Tri Z Engine Build [Archive]

El Camexican

01-26-2015, 02:26 AM

This engine only has about 6 hours on it, but I recently gave up on my aspirations to travel long distances over remote terrain on it, so I no longer see the point to keeping it trail worthy.

The engine came with a rough attempt at Phase II mods which I gingery tried to smooth over without adding to the loss of bottom end, but as much as I will defend its ability to be ridden in tight areas the fact is that it needs way too much clutching before attempting a jump to warp speed without notice. As much as I hate to admit it scares the bejesus out of me on anything but a long flat surface. I don’t know if it’s just the added traction, but it feels like it accelerates faster than my 300cc bike when it’s on the pipe.

So here goes. Below is what’s getting bolted on after the ports get another tweaking.
208919

The Sprock head has a pump dome and that’s just fine with me, I don’t believe that 2 strokes like a lot of compression to start with. Thanks to off-Road Innovations for the head and Ricochet Off-Road for the dip in orange juice. More parts may end up there before this is over.
208923

My manifold actually took the 38mm carb without a lot of fighting, but the boost bottle had to go, so a Sprock unit was picked up from Mrs. Mosh. I plan to use it with the stock cage, so it looks like some matching work and maybe even a little JB Weld will be needed.
208921208922

The fly wheel was sent out to have 5 to 6 ounces lopped off. I’d promote the place that did it, but I’m not thrilled with the workmanship, so that ain’t happening.:mad:
208920

The fuel Tee from SBDesigns here in the 3WW Store has been waiting to go on for a while now, as has the tether switch. The HD clutch springs are likely going to be needed at this point.

Also picked up a stock swing-arm from Manbearpig that will be lengthened, but how much is still to be determined.

You may have noticed some orange Yamaha decals in the photo. Still not sure about that:wondering. Input welcome.

aramid

01-26-2015, 02:47 AM

.
hello el camexican, you probably know this but just in case, you can drop power by doing the following also.

6 mm thick reed cage spacer . . this will soften power and make it a little less pipey and lite switch like.

smaller carb

reduce the amount the reeds can open.

add weight to the flywheel . . removing weight makes them less tractable so the tires suddenly spin . . more weight will smooth out the power delivery a bit and make it harder for the bike to stall when applying the rear brakes . . you can get a ring made to press over the outside of the flywheel.

mill around .020" off the bottom of the cylinder to lower the ports, then run a thicker head gasket if your compression is still higher than you want but this increases the squish distance which can increase the potential for detonation in some cases even though it lowers the compression . . its a bit of trial and error.

retard your ignition timing around .015" on the timing plate.
.

El Camexican

01-26-2015, 10:00 AM

Totally agree Aramid and if that was the goal I'd likely just put a stock cylinder and carb on it, but that's not the direction I want to go. For the amount of use it gets, it may as well just be a mild drag racer.

Darius1502

01-26-2015, 12:09 PM

Having talked with Camexican I know this guy knows his STUFF!! ITs going to be an awesome motor!!

cr480r

01-26-2015, 12:56 PM

Just curious if you have the timing specs of your current cylinder. Beyond phase 2? Have you put a wheel on it?

El Camexican

01-26-2015, 07:35 PM

Having talked with Camexican I know this guy knows his STUFF!! ITs going to be an awesome motor!!

Darius, you're making me blush. I'll be happy if it just runs as fast as a stocker when I'm done with it.:lol:

El Camexican

01-26-2015, 07:50 PM

Just curious if you have the timing specs of your current cylinder. Beyond phase 2? Have you put a wheel on it?

No sir, not yet, but that's the plan. Not sure what you mean by "Beyond phase 2?".

onformula1

01-26-2015, 08:34 PM

I think he is talking about this part-

"The engine came with a rough attempt at Phase II mods which I gingery tried to smooth over without adding to the loss of bottom end"

onformula1

01-26-2015, 08:45 PM

What reeds are you using? I would run Carbon Tech, carbon Fiber HI-Tension. Boyesen's work good as well, but I like something a bit stiffer, you could also make a reed stiffener.

You might want to run only 3 heavy duty clutch springs, especially after coming off a KTM hydraulic clutch. Maybe try that first, 6 HD's can kill your arm and are usually not needed.

Mosh

01-26-2015, 09:02 PM

I dont know trailprotrailprotrailprotrailpro about tri z's...but I do know they like the timing retarded just a bit..
And they run the best with the v force 3's...and that pump dome aint a pump dome unless Sprock re worked them. If that is the old head design that is, unless it has been turned down. If Just a fyi..

El Camexican

01-26-2015, 11:16 PM

I dont know trailprotrailprotrailprotrailpro about tri z's...:lol:

Yea, I heard that somewhere.;) If you had to pick a "random number" between 1 and 360 for that retarded timing # what would it be?

I've read many of your posts dating back to the inception of the Cool Head, great info. Compression will come up later, but for now I'm focused on the intake. You mentioned the V303A fitting the Tri-Z and that the 682m reeds are softer and work better, I assume that is for overall use more so that just top end? I'm a little leery of dropping the coin on the V-Force V303A's I see on ebay as there are multiple images, some with 6 mount holes! Can you confirm this fits the Z? and also if the angle of the block is any steeper than the stocker? http://www.ebay.com/itm/Moto-Tassinari-V303A-Delta-3-Reed-Valve-System-/321517986827?pt=Motorcycles_Parts_Accessories&hash=item4adbf7240b&vxp=mtr

I couldn't find anything on the 682m reeds on the net yesterday, so for now I'm planning to work on mating the stock cage better to better suit the Sprock manifold. It looks to me like I can add a few mm of JB weld to the top and bottom of the manifold and then blend it into the cage. On the sides I plan to just widen the manifold and shape it much like the rubber tips on the stocker.

I've got a set of Boyesen's on it now and I think I'll start with them. I ordered a second cage with the stock stops still on it to experiment with as I "feel" like I'm getting some flutter up top (it has no stops at this time as per Boyesen's instruction). It may just be fat jetting, but I don't see how a set of stops will hurt anything if I just bend them open a couple mm.

Another thought is to get a manifold spacer and machine it into a wedge so that the carb is angled up a few degrees and keeping the pod filter off the frame. It could be done to the Sprock part, but I'd rather experiment with a cheap chunk of aluminum. I know for certain that the PWK works fine tipped up a bit.

Current compression with the modified stock head is 180# and no known detonation or overheating on pump gas, but then again I didn't try to climb a dune. It runs a lot hotter than my 300 KTM in the same conditions, but still cooler than I would have expected based on what I've read. I will measure and cc the stock head when I get it off to compare it to the Sprock dome. That should be a good indicator of what to worry about.

Lots to think about. Thanks for weighing in!

El Camexican

01-26-2015, 11:36 PM

I think he is talking about this part-

"The engine came with a rough attempt at Phase II mods which I gingery tried to smooth over without adding to the loss of bottom end"
Ok, well if you've read the report you know what was suggested, so here's what I got:

- A second boost port made by punching various holes with a hand drill and then an attempt to blend them with what I assume was a tapered stone on the same drill
- No mods to the stock boost port
- Exhaust was raised, but only 1mm from where I took stock to have been
- The transition into the transfer ports looked like a combination of a terrible casting from Yamaha combined with more input from the hand drill. Good news is that not a lot of material was removed, so I smoothed them out a little and left them. This time around I plan to blend them properly and if need be JB Weld any gouges.

Boost ports after being cleaned up
208987

I think the clutch uses 5 springs. I'm ok with a stiff clutch. What does a reed stiffener consist of?

onformula1

01-27-2015, 12:22 AM

If you Goggle image- "yamaha tri-z 250 clutch hub" every picture shows 6 springs.

You can buy reed stiffeners of just cut down a old reed set & put them on top of the new reeds, you can go between 1/4 to 1/2 of the stock length reed. I always seem to land on 1/3, so cut 2/3 off the reed and clean up the ends with light sand paper, bevel the sharp points.

3 Wheel Drive

01-27-2015, 12:49 AM

Ive got an extra HD Sprock Racing base gasket if want one pm me. All the info for the Vforce3 reeds is good on the Z they will come with 4 holes no worries. Here's a pic of the reeds & HD Z gaskets:

209043

Its hard to believe after all the bling on your Z and time building that trailer, you don't have those fancy reeds yet?!:naughty:

El Camexican

01-27-2015, 12:56 AM

I've been staring at newer YZ engines looking for differences between my old 25-30 hp engine and newer 45-50hp engines. Here's what I see so far at a glance:

Tri-Z - Big OD head pipes and large wide exhaust ports
Newer YZ - Smaller head pips and ports (and of course power valves)

Tri-Z - Long, large intake tract with piston windows
Newer YZ - shorter intakes with no piston windows, but instead a port that starts in the intake floor and exits in the cases, so opens the reeds much sooner than the Tri-Z.

Tri-Z - Single slot shaped boost port
Newer YZ - Round, oval boost ports

Interesting...

El Camexican

01-27-2015, 01:03 AM

3 Wheel Drive

01-27-2015, 01:21 AM

If you have part numbers Mosh posted use them when ordering. His z build has a lot of info on all the sprock stuff and those reeds:http://www.3wheelerworld.com/showthread.php/65484-Big-Bore-Tri-z-Built-with-supporting-member-products

see post 72 ;)
http://www.3wheelerworld.com/showthread.php/142142-Someone-is-gonna-get-lucky-and-WIN-this-Custom-Tri-Z-build/page5

El Camexican

01-27-2015, 02:13 AM

I see the V-Force mentioned that thread, but no part #'s. In another thread on here from 2013 I see the owner has a "stuffer" in his 303 block. P/N AG682FM.:wondering

ironchop

01-27-2015, 11:14 AM

This thread is so full of knowledge, I got me a chubba wubba just reading it.

Thanks, y`all

El Camexican

01-28-2015, 03:16 AM

Pulled the engine out and removed the head. Did not like what I saw. The cross hatches above the exhaust port are polished out after just 6 hours of use. The port is 47.5mm straight across. According to what I've read .71% of the bore is as big as it should go. That would be 48.6mm, getting close to the max. The port is also flat across the top where it should be higher to let the rings close up before they contact the area directly above the center of the port. I hope it can be "fixed".

Put a degree wheel on it and took a bunch of measurements I'll post later. I found a website that calculates your timing after you plug in your numbers. It's telling me my exhaust timing is 190deg and my transfer timing is 126 deg. I need to learn about this calculation method because the site asked for my con rod length which I believe is 130mm. What difference does the con rod length make when the stroke is already in the equation? Maybe that's a stupid question and I'm too tired to realize it?

The other thing is the results the site comes up with. According to my degree wheel the transfers start to open 120 deg ATDC and close 60 deg ABDC. To me that's 120 deg, but they are saying 126 degees:wondering Maybe it's because they are considering the top ring as the open/close point rather than the dome?

This is going to be real learning experience.

atc007

01-28-2015, 07:41 AM

I know I'm too tired to answer the rod length right now. ..Top of piston opens and closes the windows..Always has anyhow lol... I never heard of using the ringland? Never too old to start learning lol/Are we changing/making a pipe for all the new numbers ? :) Wish I had your time lol....I hope she lands right where you want to have her. Sounds like you're cylinder or sleeve shopping first ? I think the only Z cylinder I have needs sleeved also.

YTZ drew

01-28-2015, 09:34 AM

I need to learn about this calculation method because the site asked for my con rod length which I believe is 130mm. What difference does the con rod length make when the stroke is already in the equation? Maybe that's a stupid question and I'm too tired to realize it?

I am by no means an expert, but I believe the reason the rod length is important to the calculation is because of the non-linear ratio between crank movement in degrees, and piston movement in inches/mm/whatever. The longer the rod, the more degrees the crank will move for the same given amount of piston motion near TDC and BDC. The piston in a long rod engine spends more "time" at TDC and BDC than an engine with identical stroke but a shorter rod.

cr480r

01-28-2015, 09:36 AM

Put a degree wheel on it and took a bunch of measurements I'll post later. I found a website that calculates your timing after you plug in your numbers. It's telling me my exhaust timing is 190deg and my transfer timing is 126 deg. I need to learn about this calculation method because the site asked for my con rod length which I believe is 130mm. What difference does the con rod length make when the stroke is already in the equation? Maybe that's a stupid question and I'm too tired to realize it?

The other thing is the results the site comes up with. According to my degree wheel the transfers start to open 120 deg ATDC and close 60 deg ABDC. To me that's 120 deg, but they are saying 126 degees:wondering Maybe it's because they are considering the top ring as the open/close point rather than the dome?

This is going to be real learning experience.

Timing reference is always top edge of piston, unless it's a dykes top ring. There's bound to be error between a program and degree wheel findings. The rod length and deck hight inputs are very important for accuracy with a computer program. Not to mention using a degree wheel is somewhat subjective when eyeballing opening/closing points. My earlier question was about port timing. I was curious what the phase mod worked out to in crank degrees, and if you had went beyond phase2 when "fixing" the port. Thanks for the info. 35degrees blowdown is getting up there and probably causing the scary late power hit. I would raise the transfer to 126.

MTS

01-28-2015, 11:42 AM

So how many degrees ATDC is your exaust opening? according to your wheel.

El Camexican

01-28-2015, 10:10 PM

Thanks to all who are posting. I need as much coaching, scolding and prodding as I can get. Speaking of which, what happened to Mosh's last post???:wondering:( Didn't have a chance to make notes.

CR480/MTS I am trying to properly layout my ports on paper as well as document all other info that might be needed before changing anything. I'll post them up when its presentable, but I need to make sure it is properly formatted, so I have some reading to do. ATDC was either 86 or 94, the notes are on another computer. The rest of the holes should be stock, but I see the floors are slightly below the crown at BDC, so that thicker gasket that 3 Wheel Drive was so kind to offer should add port window exposure all by itself!

At the moment I don't know if I need to consider the intake port, or the piston ports as they are never exposed in the cylinder and never completely sealed.

Something else that intrigued me is the domed piston VS perhaps a flat top. Found this the other day, so I guess there is no reason to yearn for a flat top http://www.2strokeheads.com/tech3.htm

Bill, I plan to work with the cylinder I have and yes I'm hoping to mess with the pipe before this is over, but the first version will likely look like Robot Chicken after a bad car crash (you have no idea what that means, so I'm posting a pic) I've started gathering up dented pipes from people so I can cut them up and add and subtract sections as needed. A little fire resistant duct tape might come in handy during the process.:lol:
209273

Been watching the Trikefest drags and "listening" to some of the trikes. I'm going to guess that the late Yamahondaman that has been mention many times owned the Yamaha at minute 1:20? Best sounding Yamaha since my YZ80! Anyone know where that trike is? And who owns the Kawi at 8 minutes? Both sound great.

https://www.youtube.com/watch?v=BWqGgjUrblA

fabiodriven

01-28-2015, 10:30 PM

You got me going with that video. Ronnie's Mantis was the cat's meow of it's time I'm told. I just missed him and didn't have the pleasure of lining up with him. He must have been quite the man to make a Tri-Z go fast.

I'm appreciating this thread as well, particularly the port timing. I liked that explanation about why the degree wheel might read different with a longer rod. I knew there was a significance, but I couldn't put my finger on it.

These videos aren't just to toot my own horn, I can assure you. They're more geared towards patting myself on the back. There's a really nice sounding Kawi you can see at about 15 seconds in this video as well as around the 2:02 mark. I've heard the pilot drinks motor oil for breakfast and eats fouled spark plugs and poops them out good as new.

https://www.youtube.com/watch?v=wdMt49-bsTM

http://i146.photobucket.com/albums/r275/fabiodriven/Tecate%20250/th_MOV02748.mp4 (http://i146.photobucket.com/albums/r275/fabiodriven/Tecate%20250/MOV02748.mp4)

Haha, sorry for the hijack buddy.

3 Wheel Drive

01-28-2015, 10:58 PM

Im pretty sure Orangeshee03 owns The Mantis now, it has the sickest turbo crank Ive ever seen. Theres a few pics somewhere on the forums. Im sending your gasket out Priority tomorrow, I got busy the last few days my bad. If your 2nd boost port has not been welded prior to being drilled out, it may crack at some point from vibration.

The gasket is about the only thing I have to offer, all this tech stuff with degree wheels and port timing is way over my head.:crazy:

atc007

01-28-2015, 11:16 PM

You have seen the right side intake pics of Z cylinders blown apart right El? They love to break around the cylinder nut area,,some very impressively!!

onformula1

01-28-2015, 11:47 PM

I am by no means an expert, but I believe the reason the rod length is important to the calculation is because of the non-linear ratio between crank movement in degrees, and piston movement in inches/mm/whatever. The longer the rod, the more degrees the crank will move for the same given amount of piston motion near TDC and BDC. The piston in a long rod engine spends more "time" at TDC and BDC than an engine with identical stroke but a shorter rod.

YTZ drew- Is correct, it is called "Dwell"

El Camexican

01-28-2015, 11:53 PM

These videos aren't just to toot my own horn, I can assure you. They're more geared towards patting myself on the back.

LOL!!! That's going in the haha file:lol:

I can't see the video for some reason, but I can hear your engine. Sounds a lot like mine while trail riding in tight woods.;) I'm not getting to TF until 2016, is it too soon for trash talk:naughty::lol:

El Camexican

01-28-2015, 11:56 PM

YTZ drew- Is correct, it is called "Dwell"

I have heard that term before, with ignitions I think. Is the meaning the same?

El Camexican

01-28-2015, 11:58 PM

So how many degrees ATDC is your exaust opening? according to your wheel.

86 degrees. The bottom is slightly lower than the crown at BDC

El Camexican

01-29-2015, 12:54 AM

You have seen the right side intake pics of Z cylinders blown apart right El? They love to break around the cylinder nut area,,some very impressively!!

Bad things only happen to bad people.;) I honestly wonder if there doesn't need to be something else wrong before they let go, i.e a weak stud, missing or loose alignment rings OR... (and this concerns me a lot) ... a misaligned engine.

When I dropped my engine in the first time It looked like the upped head to frame mounts were missing a washer, but then I see that others are the same and tapper to the bottom. It's like the factory made them like that:wondering. Anyway, when I was removing mine this time I noticed that the head was pushing against the right side and that there was a gap on the left. So the question is why? Tweaked frame? I should tighten that connection before tightening the rest of the mounts?

Don't know, but I do know I'm not going to run it like that again. All that force transfers to the cylinder base. Add heat, vibration and maybe a bottomed suspension and perhaps that's what's causing some of the failures. I plan to shim the upper mount after the lowers are tight and eliminate as much stress as possible from that area. My recollection is that my right side boyesen port (learning the lingo eh) isn't too different than the stock hole. I'll be sure to post photos.

onformula1

01-29-2015, 01:31 AM

Keep in mind frames do stretch, which is why Supercross & Motocross factory works bikes get a new frame every 3 races. Now think 1985-1986 trike there can be some movement.

Works bikes have the engine mounts and head stay mounts shimmed by hand by a factory mechanic. I always shim everything, some of my buddies would break the crap out of frames and when you would check them some of the welded in motor brackets would be 1/16" off, sometimes per side!

They would just tighten them up and not think about it. One race at a pro level and there's a crack starting. Check and shim if needed, start at the bottom mount and torque, go to the front mount and torque, then torque swing arm mount, last is the head stay and torque. (You don't shim the swing arm bolt)

Shimming also cuts down on vibration and on big bores using larger motor mount bolts helps with vibration too. (YZ490 trick was to drill out to 9/16" SAE) Worked on my CR500 sand drag/dune bike too.

El Camexican

01-29-2015, 01:45 AM

Great points onformula1. The mounts on the Tri-Z are small and flexible compared what you see nowadays on some bikes. The mount bolts on my KTM are so tight it's like they reamed the frame and engine holes together and all hardware is 10mm on a bike built to be light.

Obviously the swing-arm bolt on the trike is the boss of who goes where as it relates to the rest of the mounts, but the front mounts are flexible and all the other bolts are 8mm. The more I think about it the more I'm convinced that a stressed upper mount could cause the cylinders to crack when weakened by the added hole. I may punch out my mounts to 10mm as well.

3 Wheel Drive

01-29-2015, 02:08 AM

I'm pretty sure the Tri Z jugs cracked from that 2nd boost port. I've started a thread about the phase 2 wrench report mods a few years back and got a lot of replies from Raffa, Zmpolaristech, Mosh and many other Z guys.... You'll notice outside the stock boost port that its thicker than the other side without the boost port.

Before drilling out the 2nd boost port it is suggested that you lay down a good amount of reinforcing weld to strengthen the jug. In one of Moshe's builds he has large pics of the weld for this purpose. I added my own port without any weld, then off to get sandblasted and powder coated.... When it returned I noticed a very small pin hole in the thin area which was supposed to be welded/ strengthened.

The only Z guys that I know of who cracked jugs are racers, I accidently deleted that thread while editing my post... It had a lot of good info from the 3ww pros. :(

onformula1

01-29-2015, 02:17 AM

I may get some flack for this but- A KTM is a hand build and/or assembled bike to a very high standard, when I raced for Team Green Kawasaki I only got support for the 250, 500, open four stoke, Open Pro classes. No 125's at GP's I liked to race a ton of class so I raced a KTM 125 with a little support from KTM through a dealer.

After a long Grand Prix the KTM 125 only needed a good wash and a clean air filter, the Kawasaki's needed much, much more work, but boy did they work great and were very fast!

Billy Golightly

01-29-2015, 09:43 AM

Here is my .02 on things;

Ronnie ran high compression in the Zs and I think the main reason it worked right was because of his head dome design he used, and probably timing as he was always dickin around with it.

As it was explained to me, the leading cause of preignition and detonation in cylinders is the piston done, and the arch in the bottom of the head dome being at uncommon angles. This is a little bit difficult to invision without a drawing, so if necessary, use some paper. You've got the squish band which can be anywhere from 10% of bore to 60%, that is the outside ring of the dome that has an upward slope, but not nearly as aggressive upward slope as the middle of the dome. What happens is, if the squish band is at an uncommon angle (Say, it has less slope than what the angle of the piston dome is) You'll actually create a choke point and trap hot gases on the outside edge of the dome in the head and around the piston edge.

At some point, the dome dimensions on most 250cc pistons Wiseco (Maybe others also) made changed - this I was told but I do not know from first hand measuring experience. Probably for manufacturing, or different design ideas, whatever. In any case, A LOT of old original head dome designs are setup for the old piston dome dimensions. So, when you throw in a new piston with a different dome dimensions, and a more aggressive arc, it makes that pinch point.

Here, I know this probably wasn't making sense if you didn't know already what I was talking about, so here is a diagram. 209316

So anyways - Ronnie had a special head design he used that he said was a variation of a Paul Turner 250R dome pattern that he copied into a CNC program when he was machining Tri-Z heads, and that is what he ran on his and a couple other of the engines he built. I'm lead to believe that *most* issues people encountering with detonation when most other things are already in check, is caused by this issue. And piston domes probably vary from brand to brand, and even production run to production run. Has anyone here ever taken the time to actually check these angles when building a motor? I know I haven't....:lol: I mean in theory, all you have to do is measure the dome angle on the piston, and machine your squish to match (or exceed, I don't know which would be better performance wise, I would think exceeding it).

I probably should have checked this on the rotax since I'm using an entirely different design of piston in it than what was intended originally.

YTZ drew

01-29-2015, 10:00 AM

I have heard that term before, with ignitions I think. Is the meaning the same?

Same term, different meaning in the context of ignition systems.

In an inductive discharge (most battery-operated) ignition systems, dwell refers to the duration of primary circuit "on" time, measured in degrees of cam rotation (envision the 4/6/8-sided cam in an old points-type distributor). Nowadays nobody talks about dwell since we don't have to adjust point gap anymore. Dwell is now a function of rpm and the electronics in the ignition control module.

fabiodriven

01-29-2015, 02:22 PM

William that is an exemplary explanation and I can totally see the knock, why it would happen, and where it would occur. That explanation of pre-ignition is something I will take into consideration henceforth when building a motor.

Billy Golightly

01-29-2015, 02:37 PM

A kind of Ghetto way of testing the theory in an engine that has that problem (Without having to try and machine your own head or come up with a turning pogram for it, is to pull the piston, just check the trailprotrailprotrailprotrailprotrailpro up in a lathe, and cut a flat groove around the sides of it in the width of your squish band. Smooth off, and see. You'll be lowering your compression so its a double edged sword (and that alone will help with the detonation issue) but it'd be a method of trying it out.

I kind of did the opposite on a CR500 piston one time with a theory of balancing the engine by removing material off of the piston was easier than doing it to the crank and rod assembly. Worked too, smoothed it out a TON.

209320

ironchop

01-29-2015, 02:44 PM

THIS should be a sticky in Mad Scientist or something.

I just saved the link to my laptop for future reference.

ironchop

01-29-2015, 02:49 PM

At some point, the dome dimensions on most 250cc pistons Wiseco (Maybe others also) made changed - this I was told but I do not know from first hand measuring experience. Probably for manufacturing, or different design ideas, whatever. In any case, A LOT of old original head dome designs are setup for the old piston dome dimensions. So, when you throw in a new piston with a different dome dimensions, and a more aggressive arc, it makes that pinch point.

So anyways - Ronnie had a special head design he used that he said was a variation of a Paul Turner 250R dome pattern that he copied into a CNC program when he was machining Tri-Z heads, and that is what he ran on his and a couple other of the engines he built. I'm lead to believe that *most* issues people encountering with detonation when most other things are already in check, is caused by this issue. And piston domes probably vary from brand to brand, and even production run to production run. Has anyone here ever taken the time to actually check these angles when building a motor? I know I haven't....:lol: I mean in theory, all you have to do is measure the dome angle on the piston, and machine your squish to match (or exceed, I don't know which would be better performance wise, I would think exceeding it)..

A smart feller might be inclined to offer a matching domed piston with some of these new aftermarket heads out there.....as a matched set.

MTS

01-29-2015, 04:09 PM

NeverLift

01-29-2015, 05:20 PM

El I've got a stock cylinder with a cracked & rusted sleeve that I will give you for the price of shipping. If you want one to play with before you attack yours.

Billy Golightly

01-29-2015, 06:00 PM

El Camexican

01-29-2015, 07:38 PM

Mosh

01-29-2015, 09:25 PM

Ronnies stuff was not used...
I know where the domes came from. If only sprock would post.
Whatever happened to him anyway.

aramid

01-29-2015, 10:20 PM

Glad to see everyone is putting thinking caps on. How many of us have just bolted on a carb or pipe and rode around thinking we had the fastest ride around? (my hand is up).:lol:

I melted a hole through a piston on my RZ 500 exactly because of the scenario Billy brought up. I’d milled the heads down and did something really stupid (that’s another story) that really labored and heated the engine on an extended top end blast. During the rebuild I found what was causing the additional heat, so I just resolved the heating issue rather than solving the pinch point issue during the rebuild.

Yes, I used to put huge carbs on fairly mild engines thinking the bigger the carb was the more power it would make . . That's the end of my confessions.

I am definitely no rocket scientist as the statement above proves, but here’s a few things I do know that might be fun info for those that don’t know these things . . Pre-ignition and detonation are actually two completely different animals and pre-ignition can be induced by detonation.

Pre-ignition can cause a hole in a piston which is created by high heat from the pre-ignition which can last a fairly long period of time during the up stroke . . Once the pre-ignition begiuns, it can cintinue for every stroke unless something is done to reduce cylinder temps like backing off the throttle so the holes in the pistin that are created by it are not necessarily caused by just 1 upstroke that has pre-ignition . . Pre-ignition can also shatter pistons and bend rods, detonation will not shatter a piston but it can break ring lands . . Because pre-ignition is the ignition of the fuel charge before the plug sparks, and the plug is always set to fire before the piston gets to top dead center, it actually tries to push the piston downward before it reaches TDC . . This downward force combined with the upward force can be similar to running your piston into nearly a solid concrete wall at maybe 25 feet per second, thereby possibly creating a generally undesirable affect.

Another way to explain this is this . . The fuel does not actually explode, it burns in an orderly fashion and at a particular rate . . Different fuels including different brands of gasoline have a different burn rate and this burn rate is controlled by the things the gas companies mix with their gas.

As the piston comes up above the port, it obviously starts to build compression/pressure . . When the gas burns, it obviously expands which obviously creates pressure . . Since the piston builds cylinder pressure the farther it goes upwards, and the burning gas has added additional cylinder pressure that should not be there, the cylinder pressure can become greater than the piston is designed to withstand in which case it breaks and this pressure can also cause a rod to bend if the inertia/energy of the moving piston is too great for the pressure to overcome before the piston reaches its pressure limitations.

Since the piston is attached to a lot of weight that is rotating, like the crank and rear wheel etc, the energy or inertia from this is too great for the cylinder pressure to simply stop the piston before the pressure gets high enough to break it . . it’s a bit similar to hydraulic lacking but instead of liquid the lock is created by extreme pressure.

Here’s an xlnt article on detonation and pre-ignition.

http://www.contactmagazine.com/Issue54/EngineBasics.html

“Detonation: Detonation is the spontaneous combustion of the end-gas (remaining fuel/air mixture) in the chamber. It always occurs after normal combustion is initiated by the spark plug. The initial combustion at the spark plug is followed by a normal combustion burn. For some reason, likely heat and pressure, the end gas in the chamber spontaneously combusts. The key point here is that detonation occurs after you have initiated the normal combustion with the spark plug.

Pre-ignition: Pre-ignition is defined as the ignition of the mixture prior to the spark plug firing. Anytime something causes the mixture in the chamber to ignite prior to the spark plug event it is classified as pre-ignition. The two are completely different and abnormal phenomenon.”

3 Wheel Drive

01-29-2015, 10:47 PM

So my first ride on my Tri Z ended up like this:

209343

I wanted it to go faster so I added octane booster and held it WOT for way too long....LOL. The piston did not shatter but it did lock up. It must have been predetonation I guess. I'm about to split my cases again to reseal it due to oil leaking out. This time I'm bolting up my 310 kit, it's only been sitting around for a year now.

El Camexican

01-29-2015, 11:32 PM

fabiodriven

01-29-2015, 11:47 PM

As I typed out the words "pre-ignition", I foresaw a post such as aramid's last. I debated on deleting my post and educating myself after work, as the terms "pre-ignition" and "detonation" echoed and clashed in my head, and that's never happened before. You all are really making me think and teaching some fantastic stuff as well. This is obviously a wealth of information that can be applied across the board as far as internal combustion goes, but it is best off in a Yamaha thread as the Tri-Z's and big-bore IT's and YZ's have had some of the worst detonation (or pre-ignition) I've ever heard hands down.

El Camexican

01-30-2015, 12:22 AM

Spent the last three hours measuring things.

Given that my stock head was cut I can't do a 100% stock VS Sprock comparison, but I can confirm that the angle of the squish band is close to the Sprock head as pointed out earlier on here.

However, that's where the similarities seem to end. I'll post what I can now and drawings will follow.

Diameter of combustion chamber
Mine - 66.50mm
Sprock - 69.65mm

Width of squish band
Mine - .276"
Sprock - .450"

Angle of squish band (TBD)
Close. but I think there is a slight difference. Need to make a few more measurments

Squish clearance (this needs to be drawn)
Mine - First # is distance from cylinder wall Second # is what the squished solder wire measured in that location. All #'s are in inches
0.00 - .045
0.08 - .046
0.13 - .047
0.17 - .048
0.23 - .057
0.276 - .066
Squish band ends as dome radius begins

Sprock
0.00 - .042
0.08 - .043
0.13 - .044
0.17 - .048
0.23 - .054
0.30 - .057
0.45 - 0.63
Squish band ends and dome radius begins

Before anyone takes this as gospel keep in mind this is all being done by hand with a set of .0000 digital calipers. I've got great near vision and a fair bit of measuring experience. Enough to know that it would be near impossible to duplicate these numbers to within .001" if I repeat the process tomorrow.:lol:

I also took depth measurements every 1mm across the entire chamber of the stock head. I still have to do the Sprock head. Very tedious, took 4 measurements at each point. Tossed out the high and low #'s, add the remaining two and divided by 2. If any one knows of a better way to get a profile short of cutting the head in half please let me know!

onformula1

01-30-2015, 12:23 AM

onformula1

01-30-2015, 12:45 AM

nstyle73

01-30-2015, 12:50 AM

I sold my Sprock kit for the Z so I cannot compare, but on the Tecate, he cut the piston crown to match the head, so the piston that came with the big bore kit was unique.

aramid

01-30-2015, 01:04 AM

If any one knows of a better way to get a profile short of cutting the head in half please let me know!

A contour gauge might work . . Just press it into the head then lay a piece of lined tracing paper on the edge of the table then lay just the pins of the gauge on the table over the paper . . Then use a pencil with replaceable lead and make a point on the lead by rubbing it on some paper . . Then, pull the lead out far enough so the body of the pencil will not touch the pins and carefully trace it without pushing against the pins too hard because they might move . . Photocopy it or go over it with something darker . . You can then lay one tracing paper over the other and compare the differences . . Of course you can measure the heights of the lines too.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . http://t2.gstatic.com/images?q=tbn:ANd9GcTN56Yfmdg1wW3bZcIQrmVD6UWVO0WUQ VTwaZNUlgL7TWhMfO2ynVutaYw

Only 8 bucks at Amazon.

http://www.amazon.com/Empire-Level-2754-Contour-Gauge/dp/B0000TFIBW

Sorry about the big photo.

http://ecx.images-amazon.com/images/I/61FQI4s4EXL._SL1050_.jpg

El Camexican

01-30-2015, 01:15 AM

Both great ideas guys THANK YOU!!!! CCing is still pending.

onformula1

01-30-2015, 01:24 AM

Both great ideas guys THANK YOU!!!!

Your welcome but I stole the idea from Eric Gorr 25 years ago! and still use it.

His has molds of everything!

El Camexican

01-30-2015, 01:53 AM

So billy peaked my curiosity, Dug out a old wiseco piston some lay out ink and valve grinding compound, Not exactly scientific but you get the point. Stock head vs a sprock dome, Both look like they match to me. :D

Your Sprock head photos are a little blurred, but it seems the width of your band is less than mine. The outer edge of the chamber to where the radius begins on mine is .450" (measuring the slope which is probably not the right way) Yours looks smaller in the photos. Same as the Tri-Z head. Could be my imagination, or maybe I have one of the newer domes:wondering
209357

aramid

01-30-2015, 02:16 AM

Both great ideas guys THANK YOU!!!! CCing is still pending.

yeah, the mold idea is cool to, good suggestion . . If you use the mold idea, you can also use plaster of paris instead of silicone if you want . . the plaster is easy to sand if needed plus you only need to wait 30 minutes for it to dry instead of 2 days.

You can spray some silicone on a piece of metal in one area and put wax like turtle wax in another then put a dab of plaster on it then try to pull if off when it dries and use whichever one works to put on the head . . then just fill the head up with plaster.

If you want you can color the gasket surface of the head with felt pen before adding wax and plaster then after the plaster dries you can put a piece of 180 orange sand paper on flat surface and carefully sand it until the plaster is flush with the head . . the felt pen mark will be your guide so you dint sand the heck out of the head by accident.

You can put a line over the top of the plaster at the half way point then cut it just on the outside of the line with a cut off wheel . . then lay a piece of around 180 - 220 orange sand paper on a flat surface and sand it up to the line.

you can now use the plaster mold to trace out your tracing paper and save 8 bucks on a pin gauge that you may use again however, the pin gauge can be used on the piston top too then you can lay the finished tracing paper over the paper from the head shape and get a visual perspective of what's going on.

as far as measuring the head volume . . if you don;t currently have a plate you can just use your least favorote cd . . the size is perfect pluss it already has a hole in it . . if its something good like ozzie, you can just clean off the greae afterwards and it will be just as good as it ever was . . i think.

onformula1

01-30-2015, 02:38 AM

yeah, the mold idea is cool to, good suggestion . . If you use the mold idea, you can also use plaster of paris instead of silicone if you want . . the plaster is easy to sand if needed plus you only need to wait 30 minutes for it to dry instead of 2 days.

You can spray some silicone on a piece of metal in one area and put wax like turtle wax in another then put a dab of plaster on it then try to pull if off when it dries and use whichever one works to put on the head . . then just fill the head up with plaster.

If you want you can color the gasket surface of the head with felt pen before adding wax and plaster then after the plaster dries you can put a piece of 180 orange sand paper on flat surface and carefully sand it until the plaster is flush with the head . . the felt pen mark will be your guide so you dint sand the heck out of the head by accident.

You can put a line over the top of the plaster at the half way point then cut it just on the outside of the line with a cut off wheel . . then lay a piece of around 180 - 220 orange sand paper on a flat surface and sand it up to the line.

you can now use the plaster mold to trace out your tracing paper and save 8 bucks on a pin gauge that you may use again however, the pin gauge can be used on the piston top too then you can lay the finished tracing paper over the paper from the head shape and get a visual perspective of what's going on.

as far as measuring the head volume . . if you don;t currently have a plate you can just use your least favorote cd . . the size is perfect pluss it already has a hole in it . . if its something good like ozzie, you can just clean off the greae afterwards and it will be just as good as it ever was . . i think.

I have never used plaster of Paris, but it should work fine, I use silicone because it lasts forever I have molds that are 25 years old and they still work.

I don't have experience with plaster of Paris, does it hold up for the long haul?

I use a 3/8" piece on glass with a small hole in it because its heavy & you can put the hole on the outer edge so the head can be carefully rotated to get any air bubbles out. Regular water with a few drops of food coloring helps as well.

cr480r

01-30-2015, 03:10 AM

I always just used a tiny angle finder.. Plenty accurate to measure differences between the dome and crown.. Even checking squish with solder will tell you if the squish band is positive, parallel, or negative.. Or you could even leave the head and base gaskets out for mock up and use plastigage.. Don't over think it. I've always cut squish parallel or 1-2 positive if the piston has a lot of crown, use torqsoft calculator to figure the band width needed for desired msv. Squish clearance has quite an effect on msv. Then last work the bowl to get desired volume. Always works for me. I repaired a friends cr250 head that had a damaged dome. I had no way to weld it, so i took a generous cut. He wanted to run pump gas no matter what so I reduced it to around 14.7:1 CR.. To get the chamber large enough i had to use a toroid/bathtub design. It ran fantastic, he didn't trust the funky head so he later bought a oem head for it. It lost power everywhere even with more compression. Most people just bolt them on and go, but the head plays a big role on performance and should not be overlooked.

Billy Golightly

01-30-2015, 10:16 AM

Billy, I can't tell from the picture, you didn't cut the piston to the edge correct? can't tell if there is one or to cuts on there.

In other words you didn't effectively raise all the ports including the exhaust port correct?

No, I didn't do anything with the edges of the piston. I basically flat topped part of the piston, and left sort of a reverse squish band on the exterior edges. Lowered compression and lightened the piston. I went in about a half inch from the sides, and then machined flat straight across to the center. Thats why I was saying when I did this, it was kind of the opposite of working on the outside edges only.

MTS

01-30-2015, 01:10 PM

Your Sprock head photos are a little blurred, but it seems the width of your band is less than mine. The outer edge of the chamber to where the radius begins on mine is .450" (measuring the slope which is probably not the right way) Yours looks smaller in the photos. Same as the Tri-Z head. Could be my imagination, or maybe I have one of the newer domes:wondering
209357

Sorry for the crappy old cell phone pics :lol: But i measured 12 mm, .475 , Cr480 seems to have a handle on this whole deal, im just working on a few other measurements trying to get this figured out, i Do have a Ronnie head sitting here, And it appears that the Angle of the Squish is the big difference, Just need to get a smaller angle finder to get a more accurate measurement. Must say this is One of the more intresting topics of late....good work :beerYAMAHONDAMAN

ironchop

01-30-2015, 02:07 PM

El.....we use this stuff at work that's a two-part deal made by Plasti-guage (I think). You mix it up and pour it into whatever you want to make a mold of and its dry in an hour I believe. Works kickass and we frequently use it to take measurements of blind features inside of prototype parts to check difficult location dimensioning.

We get it from MSC Industrial Supply. I`ll look up the actual product name and get back with you

Billy Golightly

01-30-2015, 02:46 PM

Would great stuff expanding foam insulation work also to get a good visual (assuming you had everything greased down good where it wouldnt stick)

aramid

01-30-2015, 05:02 PM

Any of the expanding foams will work fir thus purpose . . A basic paste wax will prevent it from sticking . . Once it is poured into the head, a piece of plastic food wrap can be layed over it and slight pressure can be applied as it expands . . This will cause the foam to be denser and therefore more durable and easier to work with for this type of app . . Some hardware stores and of course amazon.com carry it.. . I have always used the 2 part foam, I have never used the single part spray foam but I guess it would work but I think it might be a bit less structurally strong . . Home Depot has some for 4 dollars but I seriously doubt it will work very well just based on the price.

http://www.homedepot.com/p/GREAT-STUFF-16-oz-Gaps-and-Cracks-Insulating-Foam-Sealant-162848/100003351

http://www.amazon.com/Dow-157860-Triple-Expanding-Sealant/dp/B0002YX9GG

http://www.uscomposites.com/foam.html

El Camexican

01-30-2015, 09:10 PM

Thanks for all the suggestions guys. I ordered up the multi pin gizmo, should have it by next weekend.

MTS, I sure hope you can post up every detail possible on that head. It would be great compare it to the Sprock dome I have as well as use cr480's math to see how they compare. Maybe a small chamber Sprock dome can be cut to that profile?

Fabio mentioned the 490 earlier. Reminded me that there is still a guy up North racing them in the veteran class. I've never met him, but he's good buddies with the guy that sold me my Duck, so I plan to pick his brain before this is over. I'm told he has a few tricks for them that makes them purr.

Anyone recall reading of a 3rd Wrench Report? It's mentioned at the tail end of one of the Wrench Report articles that can be found on the internet. The same Ducati buddy raced quads in the mid 80's. He said the local Yamaha dealer had been campaigning a Tri-Z that they added a wheel to when the ban happened. He claims that Yamaha had offered the dealers kits and instructions that included the long rod. He's certain that that engine had it and said it was flat out the fast quad on the ice bar none. The dealership was Riteway Yamaha. Not sure who may still be around from back then, but surely if such a kit or instructions existed someone else has heard of them. Could this perhaps be the III Report?

onformula1

01-30-2015, 09:43 PM

No, I didn't do anything with the edges of the piston. I basically flat topped part of the piston, and left sort of a reverse squish band on the exterior edges. Lowered compression and lightened the piston. I went in about a half inch from the sides, and then machined flat straight across to the center. Thats why I was saying when I did this, it was kind of the opposite of working on the outside edges only.

Got it, Thank You.

Very cool too.

El Camexican

01-31-2015, 12:20 AM

Started documenting the ports tonight. Not as bad as I thought it would be. I still need to deal with radiuses and angles, but its a start. Was thinking of Tecati Dan while messing with this:lol:
209398209399209400209401

onformula1

01-31-2015, 01:09 AM

Hey, El Camexican want to have some fun? Check this out-

To reach 100% Volumetric Efficiency (Doesn't always happen, but you want to get close) The intake port or intake track should be 10% to 15% larger than the carb. bore.

So the question is what size carb. should I run?

Your intake port is 41mm X 48mm, add them together = 89 divide by 2 to get a average = 44.5

Most motors run best with a carb that is 15% smaller (good for all around use & MX, SX, Gp's, enduros)
Which is- 37.82mm or 38mm carb. size.

Some motors run best with a carb. that is 10% smaller (High speed desert, but gas mileage will be worse, Dunes, Drag racing, pin the tach boys)
Which is- 40.05mm or 40mm carb size.

El Camexican

01-31-2015, 01:31 AM

El Camexican

01-31-2015, 01:32 AM

I was asked to post what it is I'm reading. I'll keep adding to this post as time goes on.

http://www.macdizzy.com/cyl_primer.htm

http://www.amrca.com/tech/tuners.pdf (thanks Beets!)

http://justyamahard350.com/articles/eric.htm

http://www.singaporebikes.com/forums/showthread.php/68266-Porting-the-2-stroke

onformula1

01-31-2015, 01:48 AM

No if you did you would need a Holley carb.

onformula1

01-31-2015, 01:59 AM

All info is good info even if its bad info its good info.

I used to read Gordon Jennings book in American Lit. in high school. (I never got caught)..LOL

El Camexican

01-31-2015, 11:38 AM

No if you did you would need a Holley carb.

That's along the lines of what I was thinking.:lol:

Also wondering about the piston windows and the third window some are adding above the stockers. Any idea what the theory is behind these? Seems a lot of engines don't use any windows. Also, if using windows is there a ratio or formula to their area or location?

MTS

01-31-2015, 02:22 PM

As far as i know the ports in the piston are more for keeping the piston crown cooler, i would not add anymore to one on a tri z piston like that wiseco for the fact that they need as much piston/ wall support as you can get to keep them quiet and long lasting. i will have some info on the HR head as soon as i can form my thoughts into a comprehedable post lol.

fabiodriven

01-31-2015, 04:28 PM

Was thinking of Tecati Dan while messing with this:lol:

So funny you say that. I was thinking the same thing when I saw your pics and I hadn't even read the post yet. I can't remember if it was the 500 or his 250 he was doing that with. Either way, that 500 engine he assembled mostly by himself ran super smooth top to bottom, it was like a 4 stroke. A lot of that is due to displacement though, but I feel as though that's the kind of power you're looking for Mexinadian.

El Camexican

01-31-2015, 08:22 PM

So funny you say that. I was thinking the same thing when I saw your pics and I hadn't even read the post yet. I can't remember if it was the 500 or his 250 he was doing that with. Either way, that 500 engine he assembled mostly by himself ran super smooth top to bottom, it was like a 4 stroke. A lot of that is due to displacement though, but I feel as though that's the kind of power you're looking for Mexinadian.

It was the 500 build. First time I'd ever seen anyone do something like that. When it comes to 2 strokes I've always been a "clean the ports up the way the designer intended, cut the head .030", put a set of Boyesen reeds in it, jet it and ride" guy.

As far as the power I seek at this point it's a mid to top rush that will try to "tear my tits off". Small bore drag engine. I don't care if it won't idle under 4,000 as long as it hauls the mail from 6,000 to 8,000

3 Wheel Drive: I will be reading them for sure, thanks.

ATC-Eric

02-01-2015, 12:09 AM

El Camexican

02-01-2015, 01:45 AM

Great info in this thread. My .02 cents on the flywheel. The vibration was off the chart when I ran a lightened flywheel by Ronnie. Had to put a stocker back in it. My lower body would be completely number after an hours ride.

Not sure how yours was lightened, or by how much, do you recall? I have yet to weigh mine against the stocker, should be about 5oz lighter, but in theory my balance should not have changed due to the way it was cut. I believe that the YZ version of the Tri-Z engine used an internal rotor which would have been a lot lighter still. Not sure how they were for vibration.

aramid

02-01-2015, 02:45 AM

.

As far as the power I seek at this point it's a mid to top rush that will try to "tear my tits off". Small bore drag engine. I don't care if it won't idle under 4,000 as long as it hauls the mail from 6,000 to 8,000

ok, if top end is what you want, this guy might be able to help if you need a pipe . . he made a few pipes for the tri z a while back and if he still has the jig, he might make more . . he is familiar with the dg pipe so he can tell you the difference between that and his . . he might have some tuning tips too or even the mysterious stage III report you wanted to find . . as you know, even though the stock pipe can be modified to boost power a bit, it will always be limited in top end power simply because t was not designed for that.

http://www.dynoport.com/

MTS

02-01-2015, 02:53 AM

so, here is a HR head, what i have found is a steep sqush band agle 19° roughly by 12mm wide.now after reading a bit i have found out alot, pretty much that sprock dome with a lesser 14° or so angle and wide squish would be more suited to low rpm\midrange power, the tight squish wide band and high cmpression all fit togther to keep detonation down and increase the heat transfer aspect. the stock head is also very close to 14° but with a much thiner width of the squish around 7mm, so the trade off being a more top end power biased to the stock head with more risk to detonation under a heavy load. the reason being is more surface of the piston crown is exposed to the flame front just before and just after TDC. now the trick thing ronnie did was esentially try and get the best of both designs i think, by running the wide band and steep angle he was able to expose more of the piston crown to make more power and was able to keep detonation to a minimum via the speed the flame could carry across the piston to the edge of the band..thus burning the fuel before it could be super hot and start detonating , this is of course just my opinion...i could be off my rocker...

onformula1

02-01-2015, 03:09 AM

Also wondering about the piston windows and the third window some are adding above the stockers. Any idea what the theory is behind these? Seems a lot of engines don't use any windows. Also, if using windows is there a ratio or formula to their area or location?[/QUOTE]

Sorry, but I feel this will be a controversial topic, I can provide a Ton of info that has been tested, used & raced with excellent results- to it didn't work better than stock, never worse than stock. (Only time wasted with No improvement, but no loses)

Last time You tried to help, and I loved the energy & info you provided & I tried to add with some info that worked & was tested over a number of years...We have a Blown Out Tread that is now buried.

http://www.3wheelerworld.com/showthread.php/170747-A-Couple-of-Tuning-Tips

PM me if you want.

cr480r

02-01-2015, 03:33 AM

The trouble with heads is it's very difficult to isolate changes for comparison basis because every parameter will have an effect on another. Squish width, angle, clearance, dome volume, etc .... You cannot change any of those without changing another. I subscribe to tight piston to head clearances on all engines. It makes sense to me that fewer end gases contributes to additional power, so I leave that constant and adjust the band width and angle to get target msv. While keeping mind of total volume. It's often said that wide squish is for low-mid, and narrow for top end . I generally agree, but it's hard to isolate those variables and keep the volume the same, assuming you wanted it the same for both applications. I picture a large shallow open dome scavenging more effectively at rpm than a deep tight one, but the results are normally attributed to the reduced end gases of the narrower squish, but that variable can be adjusted with clearance and angle... Can of worms. Keep mind of msv, and CR for the application and fuel type and it will run good.

El Camexican

02-01-2015, 12:44 PM

First of all I love theory. Good, bad, right, or wrong, it all equates to the provocation of thought which inevitably equates to learning. That said I again thank EVERYONE who is posting on here.

Now for the reality of this build. I am missing a few things that I do not foresee acquiring in the near future. A dyno, and unlimited time and funds being the three main obstacles standing in the way of achieving the perfect combination.

At this time I continue to gather numerical information that will be needed to answer questions as they come up. CR ratio, max RPM and baseline port information can all change with the addition of a thicker base gasket, or a new piston, so I want to have everything well enough documented in a drawing file that a change can be assessed without pulling out the calipers again.

If I had to predict what will happen in the end it would be that the exhaust port will be raised slightly (and narrowed 1mm if I start a new cylinder) the transfers will be widened and angled with top end in mind and a blank combustion chamber will be cut to suit the piston and other dimensions. After that a pipe will likely be modified, or built to suit.

Sorry if this doesn't sound as romantic as building a 100hp 250, with 60ft pounds of torque and a 6,000rpm power-band but I would refer anyone who is disappointed back to the three missing components of this build.:)

I get that some prefer to converse about this out of the public eye. I will take that offer up and another others that may prefer not to be questioned in public.

Thanks again to all!:beer

ATC-Eric

02-01-2015, 02:20 PM

Not sure how yours was lightened, or by how much, do you recall? I have yet to weigh mine against the stocker, should be about 5oz lighter, but in theory my balance should not have changed due to the way it was cut. I believe that the YZ version of the Tri-Z engine used an internal rotor which would have been a lot lighter still. Not sure how they were for vibration.

I don't recall how much was trimmed. I sold it off a few years back so I can't weigh it. The way it was shaved, should not have messed with the balance. I just think because it was lighter it magnified the vibrations the engine already produces. Here's a picture of it.

http://i91.photobucket.com/albums/k300/ericbsemail/P6130221.jpg

El Camexican

02-01-2015, 07:51 PM

I don't recall how much was trimmed. I sold it off a few years back so I can't weigh it. The way it was shaved, should not have messed with the balance. I just think because it was lighter it magnified the vibrations the engine already produces. Here's a picture of it.

looks like they are cut the same on the circumference, but mine also has a cut across the outer face as well. I guess the vibration could just be inherent to the engine, but I've confirmed that the YZ had a smaller diameter left cheek as well as a small rotor. If the Tri-Z shakes bad then the YZ engine may have loosened a few fillings!

3 Wheel Drive

02-07-2015, 12:36 AM

How's the rebuild coming along, any updates, pics?

El Camexican

02-07-2015, 10:10 AM

How's the rebuild coming along, any updates, pics?

Well, last night I drove North and I picked up the cylinder and gasket Never Lift and you were kind enough to part with. Thanks for the shirts and plug guys!:Bounce The contour gauge also came in to check the heads with.

I've measured and documented the port angles and had the guy that will be making my drawings over to show him what's going on. Aside from that a couple of currently banned members have contacted me via email to offer guidance and advice and I'm building furniture for the house which takes a ton of time. I will be putting that base gasket in and checking the timing again and then commission the drawings.

Will post more when it happens.:beer

aramid

02-09-2015, 09:07 PM

.

The contour gauge also came in to check the heads with.

Cool, how do you like it?

Not sure what you plan on running for fuel but if you plan on running in the higher rpm ranges and not doing any, or much, trail riding, I would look at using one of the following if you haven’t decided on an oil yet . . Most are compatible with gas and alcohol and offer better protection in the higher rpm ranges than the typical general use oils . . Unfortunately, some of the prices are not for the faint at heart.

Maxima castor 927

$9.00 a qt

http://www.maximausa.com/product/castor-927/

Shell advance racing m designed for methanol and cart racing at 9000 rpm.

$14.00 a qt.

http://www.opieoils.co.uk/p-69340-shell-advance-racing-m-2t-sae-30-kart-oil.aspx

Castrol A747 used by the 14000 rpm factory GP bikes, lol. This should work but you can’t run under 3000 for long or your plugs will load up. Available on ebay. Should call to Check compatibility with methanol vs Castrol M

$23.00 a qt

http://www.castrolmoto.com/en/our_oils_new/a747.php

Castrol M for use with methanol

$25.00 a qt

http://www.bikebiz.com.au/products/Castrol-M-Racing-Oil-5-Litre.html

Castrol XR77 The latest and the greatest, check for methanol compatibility. The A747 is an older oil.

ONLY $43.00 A QT!

http://www.easyparts.nl/documentation/3387.pdf

El Camexican

02-10-2015, 01:47 AM

.Cool, how do you like it?

It's a little stiff on the outsides and the pins can flex on the steeper slopes of the head domes, so you have to push each pin down one at a time to get an accurate contour, but for $6 bucks I shouldn't complain. It will be interesting to see how close the computer calculated cc's are VS actual.

Fuel will likely be a VP of some sort, or maybe 20% toluene with pump gas if I can't get it here. Exotics are off the option list. I ended up with 3 liters of Motul double Ester road racing oil due to my failure to read the fine print. For as much as this engine will be used those 3 liters should last a very long time.

onformula1

02-10-2015, 02:25 AM

El Camexican

02-10-2015, 09:18 AM

What computer program are you using?

For the layout drawings? Good question, I have no idea. I'm farming that out as all drawings I make myself are are limited to a napkin platform:)

aramid

02-10-2015, 07:15 PM

It's a little stiff on the outsides and the pins can flex on the steeper slopes of the head domes, so you have to push each pin down one at a time to get an accurate contour, but for $6 bucks I shouldn't complain. It will be interesting to see how close the computer calculated cc's are VS actual.

Fuel will likely be a VP of some sort, or maybe 20% toluene with pump gas if I can't get it here. Exotics are off the option list. I ended up with 3 liters of Motul double Ester road racing oil due to my failure to read the fine print. For as much as this engine will be used those 3 liters should last a very long time.

1. my apologies, i knew that was a crummy one . . they make much better pro grade ones for a much higher price . . i should have posted one of those too so you could decide . . i just didn't think about it at the time.

2. I’m guessing you have already researched this so my apologies if you know any of the following.

the motul road racing has the same number as the off road for some dumb reason so that mistake is understandable . . it is better for higher revving engines though but neither this or any of the ones i listed should be used richer than 32:1.

Mixing any solvent with gas is far more complicated than most internet searches explain . . below is a fairly informative article that but not the only one that deserves reading.

http://hydrogenpowercentral.com/content/acetone-octane-and-hydrogen

The race gas will run cooler than straight gas or a mix of regular gas and toluene of equivalent octane due to the additives in the race gas so it is by far the best but obviously most expensive option . . they make race gas with as little as 100 octane which is the least expensive.

Another example is a mix of gas and race gas to achieve 104 octane will be better than a mix of toluene or xylene and gas to achieve 104 octane.

You can also run xylene . . many use it in 4 strokes at 30%.

You can use acetone with at least one ounce per gallon . . I don’t know the max percentage before the benefit begins to be lost . . this may be the best bang for your buck overall in reducing detonation and increasing power..

You can use IMCT.

If you use too much of any of these the power can be reduced and damage can be caused.

If you have gas that has a different formulae for winter and summer than the percentage of these may need to be changed.

They can be found at home depot and home paint supply stores like Sherwin Williams here.

You can run E85, it’s octane rating is around 105 but its btu is lower than xylene and toluene.

The whole purpose of higher octane is to obviously to run higher compression since the more compression you have up to a point, the more torque and power an engine will have.

both xylene and toluene have less btu than gasoline so adding it to gas will increase the octane but reduce the btu so it’s a trade off and only testing will determine what is best for your app.

You can mix race gas with regular gas, vp suggests against this however rocket racing fuels gives you a ratio chart for how to do this and calculate overall octane, lol . . the main thing is keep it sealed and out of the sun and don’t store it for long periods . . apparently the lighter compounds in race gas can be affected by heat, light and can leech thru plastic containers.

I ran 195 – 205 static compression with vp 112 in high perf 250’s, in hot weather [80 degrees f] with an ngk 8 or 9 plug and had no sign of detonation.

20% toluene will only raise the “octane” level a few points.

Toulene Mixtures with 92 Octane Premium R+M/2...114

Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane

timing is also critical as im sure you know and it should be run as high as possible and just below the point at which the engine will detonate . . different fuels require different timing settings because of their different burn rates.

im going to guess that the tri z ignition does not have the most ideal curve for your app but if you are just looking for top end, then you can just set it for the most top end power and pray it doesn't ping at lower rpms, and of course if it does, just back it down until it stops.
.

bkm

02-10-2015, 09:11 PM

1. my apologies, i knew that was a crummy one . . they make much better pro grade ones for a much higher price . . i should have posted one of those too so you could decide . . i just didn't think about it at the time.

2. I’m guessing you have already researched this so my apologies if you know any of the following.

the motul road racing has the same number as the off road for some dumb reason so that mistake is understandable . . it is better for higher revving engines though but neither this or any of the ones i listed should be used richer than 32:1.

Mixing any solvent with gas is far more complicated than most internet searches explain . . below is a fairly informative article that but not the only one that deserves reading.

http://hydrogenpowercentral.com/content/acetone-octane-and-hydrogen

The race gas will run cooler than straight gas or a mix of regular gas and toluene of equivalent octane due to the additives in the race gas so it is by far the best but obviously most expensive option . . they make race gas with as little as 100 octane which is the least expensive.

Another example is a mix of gas and race gas to achieve 104 octane will be better than a mix of toluene or xylene and gas to achieve 104 octane.

You can also run xylene . . many use it in 4 strokes at 30%.

You can use acetone with at least one ounce per gallon . . I don’t know the max percentage before the benefit begins to be lost . . this may be the best bang for your buck overall in reducing detonation and increasing power..

You can use IMCT.

If you use too much of any of these the power can be reduced and damage can be caused.

If you have gas that has a different formulae for winter and summer than the percentage of these may need to be changed.

They can be found at home depot and home paint supply stores like Sherwin Williams here.

You can run E85, it’s octane rating is around 105 but its btu is lower than xylene and toluene.

The whole purpose of higher octane is to obviously to run higher compression since the more compression you have up to a point, the more torque and power an engine will have.

both xylene and toluene have less btu than gasoline so adding it to gas will increase the octane but reduce the btu so it’s a trade off and only testing will determine what is best for your app.

You can mix race gas with regular gas, vp suggests against this however rocket racing fuels gives you a ratio chart for how to do this and calculate overall octane, lol . . the main thing is keep it sealed and out of the sun and don’t store it for long periods . . apparently the lighter compounds in race gas can be affected by heat, light and can leech thru plastic containers.

I ran 195 – 205 static compression with vp 112 in high perf 250’s, in hot weather [80 degrees f] with an ngk 8 or 9 plug and had no sign of detonation.

20% toluene will only raise the “octane” level a few points.

Toulene Mixtures with 92 Octane Premium R+M/2...114

Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane

timing is also critical as im sure you know and it should be run as high as possible and just below the point at which the engine will detonate . . different fuels require different timing settings because of their different burn rates.

im going to guess that the tri z ignition does not have the most ideal curve for your app but if you are just looking for top end, then you can just set it for the most top end power and pray it doesn't ping at lower rpms, and of course if it does, just back it down until it stops.
.
Speaking of banned members, ^ this post has a familiar ring to it. Kinda like a ghost of barrnet past. Lol Carry on, I've got nothing.

onformula1

02-10-2015, 11:03 PM

onformula1

02-11-2015, 12:01 AM

Try this for fuel-

http://www.100ll.com/

And before you say No! read this-

By- Rich Rohrich
There are at least 100 different threads on race fuel & AvGas that will explain all this in excrutiating detail.

Here's just one of mine that I found.

The simple answer is:
100LL (Blue) Avgas seems to be the most readily available version so I'm assuming that's what we are talking about. 100LL Avgas USUALLY isn’t the best choice but it won't hurt anything.

** For those of you in a hurry, or just sick of me rambling on about this crap skip down to the bottom of the thread to the >>>>>> for a summation.

For those of you still with me, here are some details.
Contrary to popular belief this isn't 100-octane fuel. Aviation fuels are rated on an ASTM Lean/Rich performance number system. 100LL is rated at 91/96 By comparison; Unocal Leaded race gas that is used in lots of spec fuel racing classes has performance number of 112/160. 100LL is closer to 91 octane (MON); by comparison VP C12 is rated at 108 (MON).

For our purposes Avgas has a couple of problems:
1) The 90% boiling point for 100LL Blue Avgas is set at 275 degrees F, which in an engine that turns over 7000 rpm will likely make less power than a fuel that has it's 90% point lower. Pump gas has similar problems, but most good race gas will have 90% Point MUCH lower. As an example Phillips B32 has a 90% boiling point around 235 degrees F and VP C12 has a 90% boiling point around 220 degrees F.
2) Depending on the refiner 100LL can have fairly high aromatic hydrocarbon content, in the 30% by weight range. This level of aromatics will tend to make the throttle response mushy and flat in applications that see big throttle opening transitions on a regular basis. It's similar to what happens when you dump a lot of Toluene based octane booster in your fuel. Throttle response becomes a distant memory.

3) The vapor pressure and distillation curve of Avgas just doesn't seem right for our purposes. The distillation curve or Volatility curve of a fuel determines to a large degree the warm-up, transitional (on & off) throttle response, and acceleration characteristics of an engine.
Here's the simplified version:
A fuels distillation curve designates the maximum temperatures at which various points between 10% and 90% of the fuel will be evaporated as well as the maximum end point temperature. So for any Engine/Air Temperature combination there is a minimum volatility that is required for proper running. As you probably know gasoline is made up of different hydrocarbons, with different boiling points. By combining these
Hydrocarbons together you get a Distillation/Volatility curve. Some hydrocarbons (light ends) boil off at low temps some at much higher temps. Depending on the intended application, a petrochemist will blend hydrocarbons to get a curve that matches the rpm range, temp, altitude, and acceleration characteristics for the application. The problem with avgas as a race fuel is the fact it is blended for an application where
Acceleration and throttle response is not a high priority. If you think about the average light airplane application, you're talking about a fairly low compression engine that runs in a fairly narrow rpm band, and is rarely called on to provide the type of transitional throttle response that a high rpm, acceleration critical application like motocross does. What's more important to the Avgas designer is controlling mixture strength by eliminating the possibility of vapor lock and icing while making sure that light end hydrocarbon fractions don't boil off too early. The lowered rpm ranges used in these engines allow them to push the boiling point up on the upper end as well. As you can see, by using straight Avgas or by mixing various types of fuel together you are modifying a number of important fuel design parameters. You may hit on a combination that works well, but more likely you'll have an engine that doesn't detonate, but doesn't accelerate very well either. So Avgas is SAFE, but not a very good choice. The high paraffinic hydrocarbon content of 100LL makes a very good base stock if you want to play back yard petrochemist, and I believe this is how some of the smaller race fuel blenders start out. I can tell you from experience that it's a ***** to document and test various changes unless you have a lot of time and patience, so trying to come up with your own Super Fuel is probably more trouble than it is worth.

So it sounds like Avgas is really bad for our purposes, and for the most part it is, but given the sorry state of pump fuel today, Avgas is looking better all the time.

>>>>>>
Here's my short course take on things based on my experience and personal biases, (keep in mind this is pretty generalized)

- In almost every case 100ll Avgas is a better choice than alcohol pump fuels

- If you don't need the additional octane that 100LL provides, then MTBE based pump premium (especially Amoco) will tend to provide better throttle than Avgas assuming you have any jetting skill. If you can't jet you're just wasting your time worrying about any of this stuff on a stock bike.

- Mixing 100LL Avgas with a good race gas designed for your application and rpm range is a reasonable way to save some money.

- Mixing alcohol based pump fuels with ANYTHING in an attempt to make it BETTER is just a chemical circle jerk, and if you're that cheap or that ignorant you deserve the crummy performance and the insurmountable jetting problems that you will invariably be blessed with.

- Milspec Avgas is a different animal entirely, but isn't readily available so we won't worry about it.

- The correct race fuel for your application will outperform ANY of the above, regardless of whether the engine is stock or modified. The more demon tweaks hiding in your engine, the more you have to gain.

El Camexican

02-11-2015, 12:02 AM

I was referring to this part- "It will be interesting to see how close the computer calculated cc's are VS actual."

I was thinking you had a computer program you were using.

Nothing special, he uses a 3D program called Solid Works, or Inventor and it should be able to calculate the volume of a void once it drawn up.

Billy Golightly

02-11-2015, 09:48 AM

Speaking of banned members, ^ this post has a familiar ring to it. Kinda like a ghost of barrnet past. Lol Carry on, I've got nothing.

Indeed It is.

YTZ drew

02-12-2015, 12:13 AM

Speaking of banned members, ^ this post has a familiar ring to it. Kinda like a ghost of barrnet past. Lol Carry on, I've got nothing.
I thought the same, but it read more like the epa-compliant version of barnett: all the information, but with the attitude removed to to protect the environment.

Good post Aramid, very informative!

onformula1

02-16-2015, 01:17 AM

Come on give us a update or pic of this bad boy!

El Camexican

02-16-2015, 07:30 PM

Sorry, buddy. The closet thing I have to progression photos are these.
210439210440210441
I have terrible habit of starting projects during projects that I don’t have time for to begin with. All it takes is one day without parts to work with and I drop what I’m doing and start something else. Right now I have a terribly abused 2012 KTM 300XC in the shop that I would have never let the owner buy if I’d checked it for him first. An office furniture project. A kitchen installation to plan. I have to redo the roof of the house and garage, install an air exchanger and the Tri-Z is in pieces that will likely end up bolted to the XC before he finally gets it out of here.

Beside all that and a 10+ hour a day job that will soon put me overseas for a couple of weeks I’m trying to watch every game of my hockey team this season and catch at least one episode of the Sopranos every night. Good thing I run on 4 to 6 hours of sleep a day.

Fear not I will get back on the Yamaha soon!

PS. I forgot jack my own thread to the list!:lol:

onformula1

02-17-2015, 01:07 AM

Your problem is, most people when they are waiting on parts start cleaning this and that on the trike, touch up this part, paint a bit, fix something.

BUT, your stuff is soooo clean there's nothing to do, so you have to find something to do!

Keep it up, Mr. Museum trike/bike dude. I love clean stuff.

El Camexican

07-05-2015, 03:23 PM

This post has been too long in the making. For anyone thinking this project was dropped (Bill?:lol:) let me assure you a day hasn’t past when I didn’t put some thought or action into it.

Speaking of action, I came to the realization that if I just keep reading and theorizing this thing will never run again, so good, bad or otherwise it’s time to start wrenching and hope for the best.

There is no way I can coherently get all that has gone on into one post, so I will just title each aspect and spew as much info as I can under the header for now. Perhaps if the thing actually runs I’ll take the time to put it into some sort of order.

The Cylinder Head

According to what I’ve read the squish band area should range from 40% (Top end power) to 60% (bottom end power) of the cylinder bore. Here is what these heads come out to according to my math (Mr. Clean is likely shaking his head at this point;)):

- Shaved Stock Head 40.75%
- Sprock Pump Gas Head 53.92%

If what I’ve been reading is correct the stock head had no place on a “spirited” trail engine. It also might explain why they run hot as more of the piston crown is exposed to the heat generated by ignition. Regardless, on paper it should make a good drag head… except for two other things.

I proceeded to mock up the engine and check piston to head clearance a second time using solder wire. According to what I’ve read the clearance in the squish band area should range from a min. of .015” to a max of .060”. Less clearance being better for a number of reasons regardless of application. After rotating the engine once to compress the solder wire it was removed and measured in three places, 1mm from the edge, the middle and 1mm before the squish area starts to transition into the dome. These are the measurements I got starting at the outside:

- Shaved Stock Head .060” - .065” - .078”
- Sprock Pump Gas Head .047” - .059” - .063”

Again more reasons for the stock TRI Z to run hot as gases are given more space to spread over the piston crown.

Next was to CC the two heads. Bit of a PITA, but I repeated the measurements a half dozen times with the same results. Instead of filling the chambers with a syringe I instead filled them from the tap using a CD as a top and then extracted the water with a syringe to measure it. This left water in the sparkplug, but other than that worked pretty well:

- Shaved Stock Head 19cc
- Sprock Pump Gas Head 22cc

I had a 180psi reading on the engine before I pulled it down, so losing a little static compression shouldn’t be a bad thing.

So what next for the head(s)? In theory nothing, at least not until I run it. After that I can decide if I want the power band to be raised or lowered and depending on which deck either the top or bottom of the cylinder up to .030” where the squish would be as small as I’d dare go. .020” would be the likely cut.

As far as reshaping either combustion chamber I would say the stocker would need the most work to fit what is desired, so I think the Sprock head will be left as is until all other options have been explored. It seems to have hit the theoretical bull’s-eye dead center by being close to a perfect all round shape and leaving room for decking as well as being large enough to cover a 69mm bore. Some thought went into this thing.

217986

El Camexican

07-05-2015, 04:25 PM

Port Timing

This is where most of my time has been spent. Rather drop the big bucks on a CC Specialty tools I instead risked destruction of a Dremel 90 degree adaptor by grinding the housing down to the point that some of the factory sealed lubricant is seeping out of it and then ground down the shaft and collet as well as cut some of the bit shafts.

217987

This barely allowed me to get the thing into the cylinder. Unfortunately the Dremel has to be turned off and on by ones second hand and during one of the hundred or so times I had to perform this trick I managed to nick the cylinder wall twice. I think I can get away with as they are below the tops of the transfer ports. Good news is that a .5mm cut will remove them on the next rebuild. Bottom line; don’t try this at home unless you’re willing to trash a cylinder.

Without stating exact measurements (as I haven’t made a complete new port map yet) I essentially raised the center of the exhaust port another 1.5mm, the transfers 1mm as well as widening them about the same amount or more.

An effort was also made to flatten the roofs of the transfer ports rather than leave them pointing towards the combustion chamber. The exception being the boost port above the intake port which had a nasty hook in the casting. That was removed and it now points towards the spark plug. The final goal was to angle the transfers more towards the center of the cylinder than the rear of it.

So how does one test all this? I wish I knew. The only thing that came to mind was smoke or water. I tried using a cigar and ended up dizzy and coughing with no results, so the lawn hose fitting was cut off and stuffed into each port. This is where having NeverLift’s almost stock donor cylinder was invaluable.

The secondary transfer ports were a little disappointing. While the water does exit in a wider pattern than the stock cylinder, part of that width seems to be closer to the intake side of the cylinder than the water that spews through the stock ports. I’m trying to convince myself that the modified boost window will combine with this flow and create some sort of “super vortex”, but in reality in might just create a swirling glob of tranquility.:rolleyes: I simply can’t get in to that port with the tools I have to change that pattern and if I could I don’t think there’s enough aluminum to do it, so next comes JB Weld and another month added to the project… you get the point.

The seeing the water pattern come out of the main transfers made me very happy. Not only were they shooting almost straight across the cylinder from side to side (the secondary transfers were too), but they were significantly flowing more towards the center of the cylinder than towards the rear and more consistently between the two that the stock cylinder as well as wider.

It was difficult to take these photos as there is a split second during which you feel that the angle of the hose is not adversely affecting the way the water is coming out of the port, but I think these two photos show the changes to the main transfers’ best.

217990

In this photo of the stock cylinder you can see the water is shooting out of the stock port almost directly at the rear of the cylinder (perfect for bottom end power). Use your imagination a little and you can see that part of the boost port window is above where the water is hitting. Forgetting gravity for a moment this would indicate the angle of the transfer port roof is slightly towards the top of the cylinder.

Now look at this photo of the ported cylinder.

217989

The water is shooting straight out of the port and across to the secondary transfer port on the opposite side of the cylinder. Exactly how many degrees that I I don’t know, but it’s significant.

So will any of this make the engine run better? I have no idea, but it was fun to do and it will be even more fun if this thing revs like a pissed off wasp and doesn’t blow up.:naughty: Stay tuned for more unfounded, half thought out, irreversible modifications to discontinued engine parts.:lol:

barnett468

07-05-2015, 04:37 PM

.
Hello Nico . . I’m not sure what you are talking about regarding the piston crown so I have posted some general info below . . I realize you know at least some of it and you may know all of it but I posted it just in case any of it might be interesting or helpful to you.

HEAT TRANSFER

Heat transfer is complicated as you know but in general, a lot of the heat is transferred to the water by the piston sides and mostly thru the top piston ring, therefore, if the heat to the edges of the piston crown is reduced, the amount of cooling provided by the piston are reduced . . Obviously this heat must go somewhere so it will be focused more in the center of the piston which can overheat it plus more heat will be transferred to the cylinder head.

Depending upon design, in many applications a big percentage of heat is absorbed by the cylinder head then transferred to the coolant then the radiator [or fins if the engine is air cooled].

Because of this, if the crown of a piston is caused to run cooler by any means which includes the application of thermal barrier coatings, it is important that the head is able to process and eliminate this heat, but unfortunately, most water cooled engines do not have external cooling fins to help eliminate this heat.

One simply cooling aid on a water cooled engine is to add fins to the head and/or top of the cylinder . . On an air cooled engine, the fins can simply be extended outward.

Also, a lot of the heat is transferred to the cylinder walls by the top piston ring . . These rings are not always perfectly flat on the bottom or top . . Lapping the bottom and top surfaces if possible will increase heat transfer from the rings to the cylinder by increasing the contact area between the piston ring and ring land . . They sell piston ring lapping stones for this exact purpose.

COMPRESSION

We ran all our two stroke 250's at Kawi at around 200 psi cranking compression with race gas and had no detonation so you could go up a bit if you wanted provided your ignition timing is spot on for your particular app.

El Camexican

07-05-2015, 04:55 PM

.
COMPRESSION

We ran all our two stroke 250's at Kawi at around 200 psi cranking compression with race gas and had no detonation so you could go up a bit if you wanted provided your ignition timing is spot on for your particular app.

I'm actually glad the Sprock head is larger than the previous one. It will allow me as you say to go up if desired and not have to worry about going down before I even get it running. How it runs and behaves will determine the next mods. I've already made way too many without any testing. Not a good thing ever.

poolieZerUK

07-05-2015, 05:05 PM

The cost of the CC porting tools has put me off, have seen these buy not sure how they would compare?

http://www.ebay.co.uk/itm/DIE-GRINDER-KIT-2-STROKE-PORTING-/181493640872?pt=LH_DefaultDomain_15&hash=item2a41dd2ea8

Someone here may know, but they are a lump cheaper, and you only get what you pay for

barnett468

07-05-2015, 05:08 PM

.
Yeah, even at 170, its still quite respectable and I would use the same approach that you are in this type of situation . . I just posted the race bike compression so you would have some reference point as to what worked for us in high perf apps and therefore where you might be able to go with yours in the end . . The compression was similar for the pro jet skis . . Of course they had the benefit of using an endless supply of cold water so they could regulate the temp to whatever they wanted.

El Camexican

07-05-2015, 05:19 PM

El Camexican

07-14-2015, 12:36 AM

Made a little progress over the weekend. Started by taking the cylinder to PG Racing to have .020” removed from the top. Anyone remember Pedro “Speedy” Gonzalez? He’s the only Mexican to ever get a factory ride on the AMA Supercross circuit. His dad runs the business and is a heck of a nice guy who’s always happy to show off his latest projects.
218447218448218449218450

With the cylinder almost done I started on the intake. The first order was to match the rubber boot to the aluminum and then the aluminum intake to the stock cage.
The rubber was easy, but transitioning the aluminum Sprock Racing to the stock reed cage required some epoxy filler on the top and bottom as well as opening up both sides of the block.
218452218453218454218455 218462

I’ve decided to start off with the stock steel reeds with the stops opened up 1.75mm on each side and if need be I may try fiber reeds to see what the difference is. Until I can see and touch a V Force reed cage I’m not going to drop the coin on one.

Next task was to change the clutch springs. Got lucky and was able to save the gaskets. A little oil on the paper pre-assembly is a wonderful thing. Check out the mesh pattern on the clutch/crank gears. The clearest image in the Yamaha manual shows the same.
218459218460

Once the cylinder is back I plan to match the Tri-Z piston skirt to the cylinder base, take some measurements and button it up. I have a YZ piston on order, but it’s 3 weeks out, so it will have to wait its turn.
218461

Once it’s running and jetted with the DG pipe I will have to decide if another pipe configuration is needed.

onformula1

07-14-2015, 12:52 AM

El Camexican

07-14-2015, 01:02 AM

Yes, I race with him a few times, really nice guy.

He is best known for racing for- Mitch Payton’s Pro Circuit Kawasaki team and came away with a win in the 125 AMA Supercross at San Jose. He did well at the Mammoth Mountain Motocross against the best races from around the world too.

Small world. The oldest of the two shops here in MTY is 5 minutes from my house. Pedro Jr. raced MX in 11 different countries, not bad for a local boy. If you were a little older you might know this guy too 218463 He's a little heavier these days and owns a VERY nice 1992 WR250 ;)

onformula1

07-14-2015, 01:03 AM

Did you use JB Weld, the color looks close.

Just use the stock cage to try and get some high tension carbon fiber reeds for $54.95
Check with them but the 1988-92 YZ125 reeds should be correct

http://www.carbontech.com/motor/yamaha.html

Also, check how close the reed cage is to the Boyesen boost ports, if it's blocked off a lot run a reed spacer.

onformula1

07-14-2015, 01:09 AM

Small world. The oldest of the two shops here in MTY is 5 minutes from my house. Pedro Jr. raced MX in 11 different countries, not bad for a local boy. If you were a little older you might know this guy too 218463 He's a little heavier these days and owns a VERY nice 1992 WR250 ;)

It that you?

Ammex was cool, stands for- American-Mexican, Gary Jones company, 4 time AMA national champ and a very nice guy! He got hurt and Can-Am bought out his contract so he formed his own company to continue to race...Bad trailprotrailprotrailpro

Those engines were half CZ and half YZ like.

El Camexican

07-14-2015, 01:24 AM

It that you?

Ammex was cool, stands for- American-Mexican, Gary Jones company, 4 time AMA national champ and a very nice guy! He got hurt and Can-Am bought out his contract so he formed his own company to continue to race...Bad trailprotrailprotrailpro

Those engines were half CZ and half YZ like.

Me? Hell no, I still had playing cards and clothespins on my bicycle spokes when that photo was taken! #73 was sponsored by Islo and raced MX for them for many years. He also helped them develop (copy) the Husky laydown shocks by moving the mounts on his factory frame here in town and them letting them copy it.

onformula1

07-14-2015, 01:27 AM

Who else owns a VERY nice 1992 WR250?

I thought only you did. :lol:

El Camexican

07-14-2015, 01:41 AM

Who else owns a VERY nice 1992 WR250?

I thought only you did. :lol:

Nope, not mine. That bike was rebuild for him as a X-mas gift (his son-in-law is friend of mine). I did get to ride it a few weeks ago though. It needs jetting badly, so it will be back at my place soon enough:)

onformula1

07-14-2015, 01:44 AM

I always thought it was yours.

Nice present!

El Camexican

07-14-2015, 09:03 AM

I always thought it was yours.

Nice present!

Nope. I did put it on my bikepics page under "my bikes" as they don't have another option to post photos, but I've never claimed ownership. I do like that if you Google 1992 WR250 two of the four images are of that bike.:)

El Camexican

07-17-2015, 01:11 AM

Picked the cylinder up this evening and got to work. Made a new port map so I have some data for picking a pipe. Here are the short & sweet results are compared to what I started with.

- Exhaust port was raised another 1mm (now 34.5mm from top of cylinder)
- Exhaust was opened 1 mm (now 48 mm wide)
- Transfers and boost port were raised 2mm (now 52.6mm from top of cylinder)
- Main transfers were widened 2mm (now 29.5mm wide)
- Secondary transfers were widened 1.25mm (now 24.5mm wide)
- Boost port was widened 1mm (now 19mm wide)

With the port map done the piston was reshaped at the base to match the cylinder. Unfortunately a perfect match would have required removing pin boss material so I stopped there.
218629
The cylinder was then installed and I took some timing measurements:
- Exhaust opens 83 deg. ATDC
- Exhaust is open for 194 deg
- Transfers open 117 deg. ATDC
- Transfers are open for 127 deg.
- Exhaust closes 97 deg. ABDC
- Transfers close 63 deg. ABDC
Then the head was bolted on and the squish band was measured. It is now .025” at the outer edge of the piston and .042” just before it transitions into the doom. There is a .005” difference from one side to the other which seems decent considering I lapped the cases and cylinder base by hand.
Some other numbers I’ll need to make changes in the future:
- Piston dome volume = 7cc
- Head volume = 22cc
- Bore = 68.50cc
- Stroke = 68mm
- Rod length = 130mm
- Trapped compression ratio = 8.14

All you 2 stroke gurus please feel free to play with these #’s and tell me what I did wrong.:w00t:
218630

BTW special thanks to my anonymous 2 stroke coach that likes car that go in circles and turn BOTH directions;)

onformula1

07-17-2015, 03:02 AM

I like the Motul pre-mix, excellent choice.

What paint did you use on the engine, I dig it!

Very clean, as always.

Lay out fluid too? Nice I see more Sharpies these days.

barnett468

07-17-2015, 08:49 PM

.

Some other numbers I’ll need to make changes in the future:
- Piston dome volume = 7cc
- Head volume = 22cc
- Bore = 68.50cc
- Stroke = 68mm
- Rod length = 130mm
- Trapped compression ratio = 8.14

All you 2 stroke gurus please feel free to play with these #’s and tell me what I did wrong.:w00t:

Hi Nico, I wasn’t going to bother checking any of your numbers because I figured you already checked them six ways to Sunday, but after actually looking at them, I saw what appeared to be an error so I decided to check them and the following is what I got . . Unless I have alzheimers, or my calculator is wrong [either is possible, lol], assuming your head gasket thickness is 0 [if you are using 0 rings], and your deck height is 0, your static/uncorrected, or "trapped" compression is 17.707 . . If I convert the piston dome number to a dished number of 7 cc, I get use 9.64.

If I'm wrong, please feel free to tell me where my error is so I and everyone else can tell myself how stupid I am, lol.
.

El Camexican

07-18-2015, 01:48 AM

.

Hi Nico, I wasn’t going to bother checking any of your numbers because I figured you already checked them six ways to Sunday, but after actually looking at them, I saw what appeared to be an error so I decided to check them and the following is what I got . . Unless I have alzheimers, or my calculator is wrong [either is possible, lol], assuming your head gasket thickness is 0 [if you are using 0 rings], and your deck height is 0, your static/uncorrected, or "trapped" compression is 17.707 . . If I convert the piston dome number to a dished number of 7 cc, I get use 9.64.

If I'm wrong, please feel free to tell me where my error is so I and everyone else can tell myself how stupid I am, lol.
.

I wouldn't say stupid, maybe I just have the nomenclature wrong. I agree with 17:1 uncorrected, but I take trapped to mean corrected.

I used this site http://www.torqsoft.net/compression-ratio.html and instead of a 22cc combustion chamber I used 15cc to account for the 7cc piston dome and got 9.48.

In the earlier post I said 8.14:1, but that was because I decided to add the squish volume space to the equation. In hindsight I think it is accounted for in the chamber cc number, so 9.48:1 corrected compression is likely the correct #.

But enough boring math! I bolted it in and hooked up the gauge and got a reading of 177psi. At our altitude on a hot day that works for me. It might even run on pump gas.

I also bored out the from mount to 10mm and shimmed the head mount. The front mount was using an 8mm bolt with over 1mm of slop in it! The current hole is less than .010": larger than the bolt and it fits like a glove. I could not do the lower mount as there isn't enough meat on it to go to 10mm. also made a mount for a new rear brake reservoir, but had to run a nose in a hose to get it to work in the old large I.D. hose. I put a sample of the new hose (I think it is modern high pressure fuel line, its grey) in a plastic bag of brake fluid to see how it reacts.

Oh, and to use that website formula you need to know the top of the exhaust port is 34.5mm from the top of the cylinder and that the piston is pretty much flush with it at TDC

El Camexican

07-18-2015, 02:34 AM

[QUOTE=onformula1;1376512]Also, check how close the reed cage is to the Boyesen boost ports, if it's blocked off a lot run a reed spacer.[/QUOTE

Forgot to mention the boost ports are over 1cm from the cage, so no worries:)

barnett468

07-18-2015, 03:09 AM

.
ok, xlnt . . 177 is great but you already knew that and its only 7 higher than your calculated projection of 170 which is actually incredibly close . . you probably already know that you will gain almost 5 psi per every 1000 ft drop in elevation and vise versa which is why im guessing you were asking what the elevation is at the racetrack.

just for reference, the more common terms i see and use for the type of compression you are referring to is dynamic compression or corrected compression . . it's probably a bit more universally understood . . the term "trapped" could be understood either way depending whom you ask but it probably would more commonly mean dynamic so the error would be more on my part.

you ,may already know this too but just in case you don't, E85 gas, which I think you said you don't have, is equivalent to around 105 octane, so at least in the states, it is a cheap alternative to race gas if you just need a bit more octane than 91 or 93 etc . . In fact, I know a few people that run it in their V8 engines with around 12 to 1 compression . . or a more comparable number might be around 195 - 200 psi cranking pressure.

Anyway, it looks way too nice to run now anyway.

Also, in case you didn't know, the squish band area should be included in the head volume simply because it has volume . . One easy way to accurately measure head volume is to install the spark plug you plan t use . . turn the head upside down . . put a thin layer of grease around the gasket sealing area . . then place a CD on top and give it around 1/8th of a turn to seal it well . . then just use a graduated syringe or cylinder and fill the head up.

0 deck would be when the edge of the piston is flush/even with the top of the cylinder.
.

YTZ drew

07-18-2015, 09:24 AM

. . . then place a CD on top and give it around 1/8th of a turn to seal it well . . then just use a graduated syringe or cylinder and fill the head up.

Nico, this is an awesome thread, and an amazing build. Your work is outstanding! And Barnett, you sir are a genius! Why didn't I ever think to use a CD? Great idea.

El Camexican

07-18-2015, 10:57 AM

Barnett, I did use a CD because some guy named Aramid that used to be on here suggested it. It worked very well. (Whatever happened to that guy:wondering) but instead of filling with the syringe I found it easier to fill from the tap and when all the air bubbles were out I extracted the water with the syringe. Much easier and if I'd have had a helper to hold the head it would have been super easy.

The term "trapped" came from one of the compression calculation sites and made perfect sense to me even though I'd never heard it before. As the piston passes the top of the exhaust port the gases are "trapped". Makes so must more sense to my simple brain that the term "corrected" which makes it sound like you need to fix something you didn't know was broke.:lol: It might have originated from England, or Australia. They have their own way of saying things there eh.

Ok, so back to brass tacks. Please explain to me why I need to consider the squish volume if the outer edge of the piston crown is flush with the top of the cylinder and the combustion chamber volume has been measured? In other words all the squish volume is machined into the combustion chamber of the head.

If the squish band ring of the head was flush with the mounting surface of the head (like my shaved stocker is) and the space below it was taken up by head gasket thickness, or the piston crown was below the top of the cylinder at TDC then I could see this being necessary to account for, but with the elimination of the gasket and the decking of the cylinder I no longer have that volume.

I am 99% sure there is no need to consider additional volume on my setup and I think the proof is in some rough pre-assembly math that indicated that if that space did exist my measured psi would have been significantly lower than what it ended up being. Good thing too, I was very worried about that. The only way remaining to get more psi in this setup would have been to buy a smaller dome, or do a bunch of machining to the one I have.

Thanks for posting everyone, you too Aramid, wherever you are...

as far as measuring the head volume . . if you don;t currently have a plate you can just use your least favorote cd . . the size is perfect pluss it already has a hole in it . . if its something good like ozzie, you can just clean off the greae afterwards and it will be just as good as it ever was . . i think.

barnett468

07-18-2015, 04:07 PM

.

Barnett, I did use a CD because some guy named Aramid that used to be on here suggested it. It worked very well. (Whatever happened to that guy:wondering)
Xlnt…I didn't see that post because I didn’t read all of them . . He was a friend of mine whom got back into 3 and 4 wheelers recently so I told him he should sign up because he can find parts and info if he needed . . He actually used to work on them too and knows quite a lot, but I was the one whom told him about the CD trick so I’m glad he passed the info along to you and that it was useful . . He got very busy again with his work and general life issues.

Ok, so back to brass tacks. Please explain to me why I need to consider the squish volume if the outer edge of the piston crown is flush with the top of the cylinder and the combustion chamber volume has been measured? In other words all the squish volume is machined into the combustion chamber of the head.

I apologize in advance if I don’t understand your post correctly, or if like some of my answers, this one is confusing. :lol:

Even though the squish band closely follows the crown/dome of the piston, there is still a space between them when the piston is at tdc . . In fact, you already measured this space/clearance with your solder.

In your case, if you spread the grease so you had the same diameter as the cylinder bore, you already included the squish band when you measured the volume, in which case, there is nothing else to calculate on the combustion chamber.

El Camexican

07-18-2015, 04:24 PM

.

Xlnt…I didn't see that post because I didn’t read all of them . . He was a friend of mine whom got back into 3 and 4 wheelers recently so I told him he should sign up because he can find parts and info if he needed . . He actually used to work on them too and knows quite a lot, but I was the one whom told him about the CD trick so I’m glad he passed the info along to you and that it was useful . . He got very busy again with his work and general life issues.

I apologize in advance if I don’t understand your post correctly, or if like some of my answers, this one is confusing. :lol:

Even though the squish band closely follows the crown/dome of the piston, there is still a space between them when the piston is at tdc . . In fact, you already measured this space/clearance with your solder.

In your case, if you spread the grease so you had the same diameter as the cylinder bore, you already included the squish band when you measured the volume, in which case, there is nothing else to calculate on the combustion chamber.

I think we are saying the same thing (my previous post and your last sentence) so let me try to say it another way. The space within the combustion chamber that the solder was squished in is the same space that water occupied when the doom cc was measured, BECAUSE there is no head gasket and the piston dome stops flush with the top of the cylinder. Therefore, adding the squish volume to the formula as a negative would duplicated that amount of void as it was already accounted for in the 22cc chamber volume.

I just noticed that aramid is on the banned list. Must have been that crack about the Ozzy CD.

barnett468

07-18-2015, 05:46 PM

.

I think we are saying the same thing (my previous post and your last sentence) so let me try to say it another way. The space within the combustion chamber that the solder was squished in is the same space that water occupied when the doom cc was measured

That's all you need then . . Whatever is measured, is exactly what the volume is, irregardless of what any calculations say.

The calculators then have a place to enter compressed gasket thickness and gasket bore id . . Obviously, if there is no gasket, you would enter 0, however, some calculators are finicky and require 0.0, or if your bore is 4" for example, they require 4.0 instead of just 4 . . I can also tell you that at least when using calculators to determine dynamic compression on a 4 stroke, some calculators vary by around 10% for some unknown reason, so I suggest ones I know are fairly accurate to people like the three below.

This one asks for piston ring height,piston clearance, and the amount of camshaft advance etc.

http://www.projectpontiac.com/ppsite15/compression-ratio-calculator

http://www.wallaceracing.com/dynamic-cr.php

https://www.uempistons.com/index.php?main_page=calculators&type=comp

This being said, calculating accurate dynamic compression is a bit more complicated because the compression varies with the amount of intake/fuel charge in the cylinder, so to calculate it more accurately, you need a special computer program that is around $150.00, but it also calculates other things like hp and tq based on different intakes and heads from different mfg’s . . It asks for cam duration and valve lift and several other things . . One decent one is called desktop dyno 2000, but you need to buy the upgrades and various intake and cylinder head downloads to get the most accurate results.

Also, cylinder filling is also affected by the exhaust due to the scavenging affect it has . . The amount an exhaust scavenges is mainly determined by the header tube size and length and collector type and size of the tail pipes and the muffler type etc . . This being said, you can install just about any exhaust system on a 4 stroke and it will still decent, but that is far from the case with a two stroke . . I did a lot of 2 stroke pipe testing at Kawi as well as some with Harry Klemm and Dave Miller, and of the pipes we dynoed, the ones that had the most peak power weren't often the ones that worked the best because the power was not in the right area or the right type for the app.

If you just want to play around on a super budget version for fun, you can download the one below from Comp Cams . . It takes less than 10 minutes to do it all . . I entered maximum everything on it one day just for fun so it was like 600 ci with 22 to 1 compression and a supercharger with 20 lbs of boost and nitrous etc, and it said something like 3,000 hp at 1800 rpm. :lol:

http://www.compcams.com/v002/Software/SoftwareRegistrationContent.aspx?prog=1&title=CamQuest6

Bren_downe

07-18-2015, 06:11 PM

"Ozzie" should read Ozzy. We don't want the prince of darkness after you guys…
Good thread. Carry on.

barnett468

07-18-2015, 06:45 PM

.

"Ozzie" should read Ozzy. We don't want the prince of darkness after you guys…

He was referring to the Greatest Hits album by Ricky Nelsons dad from the Ozzie and Harriet show.

...........http://tvseriesfinale.com/assets/ozzieandharriet09a.jpg

OMG...I think my spleen just burst.

. . . http://www.picgifs.com/graphics/l/laughing/graphics-laughing-867787.gif

El Camexican

07-18-2015, 06:56 PM

"Ozzie" should read Ozzy. We don't want the prince of darkness after you guys…
Good thread. Carry on.

Dangit! I thought it was, but "aramid" spelt it Ozzie, so I did the same (Never bought the CD) Oh well I have an edit button, so I can fix it:naughty:

barnett468

07-18-2015, 09:20 PM

.

Nico, this is an awesome thread, and an amazing build. Your work is outstanding! And Barnett, you sir are a genius! Why didn't I ever think to use a CD? Great idea.

Thanks for the generous words, although I doubt I am that worthy . . I actually don't remember how I got the idea so I can't claim credit for it, not that I really care anyway, mainly because they don't offer a set of steak knives with prefabulated amulite blades and finely crafted, artisan designed, faux wood handles and a four place setting of monogramed paper doilies for good ideas here.

Actually, I do [or did] a lot of chamber measuring because I build high perf engines for street cars and thought there must be a better plate that’s easier to work with for motorcycles.

barnett468

07-18-2015, 09:27 PM

.

Oh well I have an edit button, so I can fix it:naughty:

咬我。。哦，我想你的山羊是最美丽的

El Camexican

07-19-2015, 03:12 AM

.

咬我。。哦，我想你的山羊是最美丽的

"Bite me . . Oh, I think you are the most beautiful goat"

Damn, you better stick to the English menu the next time you order Chinese:lol:

barnett468

07-19-2015, 03:44 AM

"Bite me . . Oh, I think you are the most beautiful goat"

Damn, you better stick to the English menu the next time you order Chinese:lol:

lol, I actually typed in "bite me . . I think your goat is most beautiful" . . I must have used the same bad language translator that lindsay lohan used to translate arabic, but yeah, after seein the translation you got..i think your right, i might end up with some anatomical part id rather not eat if i use it.

tri-Z ripper

07-19-2015, 11:32 AM

hey that's my black Tri-Z now when Deepa was still running it! in the bottom video those where the days! lol

El Camexican

07-19-2015, 11:59 AM

hey that's my black Tri-Z now when Deepa was still running it! in the bottom video those where the days! lol

You lost me partner. What video and what Tri-Z?

poolieZerUK

07-19-2015, 07:00 PM

onformula1

07-19-2015, 07:05 PM

^ That's a wide exhaust port for a cylinder with no bridge, I hope it works out for you.

Sent from my SM-G386T1 using Tapatalk

poolieZerUK

07-19-2015, 07:24 PM

The motor it came from was off ebay bought for the crank cases.
It had been snatching the rings but the bore and piston were fresh, there was no chamfer round the ports which I had put down to poor workshop practice.

I added some chamfer and it runs smooth so was going to give it a try.

It's on it's penultimate bore so I guessed it must have been ok prior to last re bore?
Worth a punt as it came with fresh rings?
But I appreciate what you are saying.

Mexico sorry for nicking some of your thread:)

onformula1

07-19-2015, 07:59 PM

El Camexican

07-19-2015, 08:59 PM

Made up an etching of the ports of a tri z barrel.
I have not ran it so can't comment on performance, but it has been ported and it looks to be good work.
Exhaust port is 58mm wide x 37mm deep and 35mm from deck.
Expecting more top end!

I don't think you are measuring it correctly. If is was truly 58mm it would be into the transfer ports. The measurement is to be taken straight across the port map with the map wrapped around the piston, NOT flat as I suspect you have it when you get 58mm. All other measurements can be done flat, but the horizontal measurements are to be done across the arc.

You also want at least 6mm between the exhaust port and each of the transfer ports, or something bad happens with the flow. Maximum exhaust port width on that jug with a 70mm bore would be about 49mm. If it's bigger than that you'll be too close to the transfers and the rings might catch.

No I am not an expert on this topic, but I have been reading about it for months and I did stay at a Holiday Inn Express a few weeks ago which means nothing to you on that side of the pond, but believe me it's critical to this topic.:p

barnett468

07-19-2015, 09:12 PM

I am not an expert on this topic, but I have been reading about it for months and I did stay at a Holiday Inn Express a few weeks ago...

If that was in Mexico, wouldn't it be called "Vacaciones en Express", or did I just did I just say that I would like to have a quick vacation with your goat?

El Camexican

07-19-2015, 10:28 PM

If that was in Mexico, wouldn't it be called "Vacaciones en Express", or did I just did I just say that I would like to have a quick vacation with your goat?

We actually have them down here. What we don't have is La Quinta (Spanish for "Right next to Denny's") go figure.

poolieZerUK

07-20-2015, 01:07 PM

I don't think you are measuring it correctly. If is was truly 58mm it would be into the transfer ports. The measurement is to be taken straight across the port map with the map wrapped around the piston, NOT flat as I suspect you have it when you get 58mm. All other measurements can be done flat, but the horizontal measurements are to be done across the arc.

You also want at least 6mm between the exhaust port and each of the transfer ports, or something bad happens with the flow. Maximum exhaust port width on that jug with a 70mm bore would be about 49mm. If it's bigger than that you'll be too close to the transfers and the rings might catch.

No I am not an expert on this topic, but I have been reading about it for months and I did stay at a Holiday Inn Express a few weeks ago which means nothing to you on that side of the pond, but believe me it's critical to this topic.:p

Well spotted, schoolboy error on my behalf.
How are you getting an accurate measure?
Will have a butchers at it later.

El Camexican

07-20-2015, 06:09 PM

Well spotted, schoolboy error on my behalf.
How are you getting an accurate measure?
Will have a butchers at it later.

No worries mate, I’m learning here too. I thought it was done the way you did it a few months ago, but just imagine that a solid mass needs to pass through the hole and you will know exactly how to measure it.

I will go so far as to say that “exact” measurements with conventional tools is almost impossible. The best us do-it-yourselfers can do is be consistent in the way we take measurements for comparative purposes.

A perfect example of a fudge factor measurement is the chamfers of the ports. If you stuff a piece of paper folder into the cylinder and work around it with your fingers to leave an impression on the paper (works best if the cylinder is a little dirty) you are going to get a transfer of the port image that is a little fuzzy at best on the edges. Realistically the chamfer is going to appear in that fuzzy section, so I then spread the paper out flat and trace the center of the fuzzy edge with an ink pen (I press hard to leave a groove). I’ve read some people then cut the windows out with a razor and form a circle to measure, but I just wrapped the paper around the piston and let the tips of my caliper drop into the groves that the pen made. I guess if you had to have it more exact you could bore the cylinder and map the ports on paper before chamfering them.

For comparative purposes (before and after) you can do it any way you want as long as it is done the same way each time. The reason you would need to do it “correctly” and remove the chamfer from the numbers is if you are asking someone to build you a pipe, or offer advice on another modification like changing port timing. Lying to your pipe builder about the size of your ports will do you no favors. It’s like buying the Magnum sized condoms to impress the checkout girl and then having them fall off at the worst possible time.

Same thing with checking the port timing. Each action effects the next. You must find TDC and then decide where to determine a port window opens of closes. I first thought it would be after the rings pass the chamfer, but it isn’t. It’s when the dome passes the open window of the port. How can you tell to within 1 degree? Good question, maybe a feeler gauge? I used my nearsighted vision to pick a spot and repeated the process a dozen times till I kept getting the same reading. (It’s so much easier to move the crank around on a 2 stroke as you can turn it back and forth without fear of bending anything) It is entirely possible that someone else doing the same thing on the same engine could come up with results that differ by a couple of degrees.

poolieZerUK

07-20-2015, 06:13 PM

Ok a quick measure says
exhaust port 52.75mm ish less the chamfered portion
piston dia. is 69.7mm ish

need to measure the Sprock dome volume as I can't remember which one I got, and I've ordered a degree wheel to get some meaningful figures.
going to run the Sprock intake with the with V force 3 reeds and Dyno port pipe and 38-39mm carb
was planning on getting YZ ignition but may go with the lightened flywheel

The reed cage that came with the ported motor was well eased and sporting boyesen petals but I already had the v force which appear to be quality items.

Keep up the good work:)

El Camexican

07-20-2015, 06:23 PM

Two questions: Can you post a photo of that exhaust port that shows its proximity to the transfer ports? Also, can you measure how close the exhaust is to the transfer ports at is closest point? I think the rule of thumb on a non-bridged port is 70% of bore. If you're at 70mm 49mm is about as far as you would want to go. Not saying the rings will catch (I have no idea), but I'd be concerned with your number.

onformula1

07-20-2015, 06:29 PM

70 percent is my full blown maximum, and I would not ported it that far unless I added a bridge.

Sent from my SM-G386T1 using Tapatalk

barnett468

07-20-2015, 07:07 PM

Ok a quick measure says exhaust port 52.75mm ish less the chamfered portion piston dia. is 69.7mm ish

going to run the Sprock intake with the with V force 3 reeds and Dyno port pipe and 38-39mm carb was planning on getting YZ ignition but may go with the lightened flywheel

What type of clutch do you plan to use?
.

poolieZerUK

07-20-2015, 07:09 PM

Will get photo tomorrow showing port map and cylinder.

Transfer ports measure looking from the front 8.3mm LHS 9.1mm RHS from the exhaust port not adjusted for chamfer

Piston has 175 stamped on dome

If it's no good it's no drama, but it would be nice to have a score

Looking at it there has been a lot of work put into it, and as you know to turn out this kind of thing isn't easy.

onformula1

07-20-2015, 07:46 PM

Can you post some pictures there maybe a few "tells" that with help out.

Sent from my SM-G386T1 using Tapatalk

El Camexican

07-20-2015, 11:52 PM

poolieZerUK

07-21-2015, 05:45 PM

218823218824218825

218826218827218828

re-sleeve is an option as it's only one oversize left in it, was just going to run it to see if it's viable.

El Camexican

07-21-2015, 06:40 PM

I know pictures like this can be deciving, but I don't see how your exhaust port can be that wide. It looks narrower than mine. I say this because of its proximity to the transfer ports. They look almost as though they're the same distance apart as stock.

Please check your # again. dirty the cylinder a little with a shot of WD 40, take a piece of stiff paper (I use office folders) and don't worry about aby thing but the width of that port. In other words you can just use a half circumference long piece. Place it firmly over the port and tight against the cylinder wall and rub your finger firmly around the port until you are sure you've left an impression on the paper. Make sure the paper doesn't move while you do this!

Then remove the paper, lay it out on a table and trace the port out with a ball point pen. If the imprint on the paper is 1mm wide center the pen on that line. Then wrap the paper around the piston and using a decent quality caliper (make sure you zero it out) measure across the widest point between the two sides of the ink marks. I suspect (and hope) you'll get 47-48mm. Good luck!:beer

tri-Z ripper

07-21-2015, 06:44 PM

You lost me partner. What video and what Tri-Z?

sorry the video Fabiodriven posted of him beating the old Tri-Z.

barnett468

07-21-2015, 07:11 PM

.
.

218827

re-sleeve is an option as it's only one oversize left in it, was just going to run it to see if it's viable.

It looks to me like it has already been run . . If the porting was done prior to it being run, then it obviously didn't catch a ring at that time, therefore, it shouldn't now.

I would just make sure there is at least a small chamfer or radius along the top edge of the port.

The fairly large upper corner radiuses/arc your exhaust has, also greatly reduce the chance of the ring catching . . From what I can tell by the photos, I wouldn't loose one minutes sleep over it.
.

El Camexican

07-21-2015, 10:13 PM

A sketch was made of my DG pipe this evening. I’m planning to send my specs into a company that will respond with what they calculate to be the best pipe design and I want to see how much it differs in design from the DG.
218834

I think I have everything I’ll need with the exception of putting a tach on the trike and a 6” exhaust pipe and finding up where the power band hits when run like that. I don’t recall the reasoning, but I think it has something to do with matching the crankcase and intake volume. More on that later.

A gallon of pre-mix was dumped into the tank and the engine was fired up. You can tell immediately that there’s less going on at low RPM than there was before and it seems to sing up pretty quickly, although I hate giving an engine in neutral much more than an aggressive blip, so I’ll have to get up up the ramp and onto the street ASAP.

Next up after the pipe will be the swing arm. Not sure how I’m cutting it yet as I don’t have access to a large band saw, but I’ll figure something out. The end result will be an extra 4.0 inches so I can stay in the modified class at TF.
218835

And finally the issue of aesthetics. To KTM or not to KTM, that is the final question. These Yamaha decals are itching to go on the new plastic, but then again there is always the option of covering the whole thing with racing stickers. Nothing screams high performance 2 stroke like a massive CRANE CAMS decal!
218836218837218838

barnett468

07-21-2015, 10:26 PM

And finally the issue of aesthetics. Nothing screams high performance 2 stroke like a massive CRANE CAMS decal!

OMG...There goes my spleen.

. http://www.freesmileys.org/smileys/smiley-laughing025.gif

christph

07-21-2015, 10:40 PM

El Camexican

07-21-2015, 10:54 PM

I'm curious, what's the company that is calculating your pipe design? I've used a program called the "Pipe Wizard" to calculated pipe dimensions but have yet to build one. On a side note, I just put an NOS Bassani on my Z and Wow! what a difference from the DG. The Bassani hits a lot harder than the DG but has a more narrow power band. Of course, you would expect that from the different designs. The condenser cone on the Bassani is steeper and shorter than the DG.

I'm hoping RPM Works can do it, but the link on their site for ordering specs is non-existent, so I sent them an email, but no answer yet. I'm sure there are others as well. I'd prefer not to get a pipe off the shelf. I have a bunch of old 250/300cc dented dirt bike pipes as well as a spare DG that I'm hoping I can cut up and cobble together into the configuration the pipe programed spits out. If I can and it works I may get a nice one built. I may contact Dyno Port as well. They've made them in the past, but they might not do a custom, but you never know, as they say in Spanish: "With money dances the dog"

onformula1

07-21-2015, 11:01 PM

Jemco in Texas builds a great pipe, Oscar Mayer is very happy with the pipe they custom built for his son's quad.

They should have jigs for a Tri-Z pipe.

El Camexican

07-21-2015, 11:17 PM

Look what I found with a Jemco search :)
http://www.3wheelerworld.com/showthread.php/112006-Jemco-Tri-Z-310-NICKEL-PLATED-Pipe!!/page2
Guess I'll send them my spigot diameter :lol:

barnett468

07-21-2015, 11:38 PM

.

Look what I found with a Jemco search :)
http://www.3wheelerworld.com/showthread.php/112006-Jemco-Tri-Z-310-NICKEL-PLATED-Pipe!!/page2
Guess I'll send them my spigot diameter :lol:

Maybe they make a pipe with threads on it that you can screw either spigot onto by now.http://www.freesmileys.org/smileys/smiley-laughing013.gif
.

onformula1

07-21-2015, 11:39 PM

^ Well...... I guess someone grabbed the wrong part. They have been building pipes so long, I guess their time was up on that one.

bkm

07-21-2015, 11:49 PM

Tri-Z decals look very nice.

Sent from my SCH-I535 using Tapatalk

onformula1

07-22-2015, 01:49 AM

All your stuff looks nice and is very clean and well built.

I dig the Katoom theme, plus it matches your other hot chicks... :lol:

poolieZerUK

07-22-2015, 02:02 PM

Here's how I came about the measures:

218870218871

I made two etchings at the same time so I could compare them, as I said the first measure was done quickly with a rule just redone with a caliper and it reads 51.7mm ish.

El Camexican

07-22-2015, 09:51 PM

Spoke with John at Jemco today and I think he'll be making the pipe. To say his website sucks would be an understatement, but I'm not looking for a website, so I'll give him a try.

With spare time on my hands I pulled out the decals and made the transition back to Yamaha. If it ends up running like crap its better that people don't think it's a KTM:lol:

218873218874218875218876

onformula1

09-05-2015, 09:46 PM

Any updates?

Sent from my SM-G386T1 using Tapatalk

El Camexican

09-05-2015, 09:53 PM

Any updates?

Sent from my SM-G386T1 using Tapatalk

The Jemco pipe has been sitting in Laredo for about a month waiting for me to pick it up. As soon as it's mounted and tuning begins I'll be posting.:beer

El Camexican

09-05-2015, 11:15 PM

It`s really nice .......i like it alot !! Don`t get it dirty !

When are you coming to see it?

El Camexican

09-30-2015, 07:26 AM

Finally got the pipe home. Looks very trick from a few feet away. Get a little closer and it starts to lose a little of its “wow’ factor. There is a dent that I didn’t notice when I unpacked the pipe. It could have happened in shipping, I have no way to know, but I hope I can pull it out with a torch and a wet rag.

I am very aware that carbon steel is a mother to TIG weld, so I’ll let the close up photos speak for themselves. I will however say that I did request a third spring hoop that I didn’t get (offered to pay if need be) and also I requested that the collar fit directly onto the cylinder snout and gave dimensions. It ended up coming with the larger collar, but that’s fine as I have one of Muthey’s nice little collars that will fix that right up.

I plan to finish the weld on the mount up and add a third spring hoop before shooting some WD-40 in it tonight to make sure there are no pin holes. At least with this pipe I can heat it and weld on it and it won’t look much different.
222225222226222227222228222229

barnett468

09-30-2015, 03:43 PM

I am very aware that carbon steel is a mother to TIG weld,
i've only seen gas welded pipes . . the "old" guys like dave miller and harry klemm are masters at gas welding . . the shape of your pipe looks cool, but yeah...your welds look like i did them....on a GOOD day. :lol:

ironchop

09-30-2015, 04:35 PM

yeah. I`ve seen better tigs on carbon steel than that. I had trouble with cracks in tig welds on carbon steel but I`ve never had an issue making a clean bead. Really, it`s hard to armchair quarterback from all the way over here so maybe there was something else going on I didn't realize.

outside of that, I would be most pissed about that good-sized dent. That's not good for any 2smoke pipe as you well know and wether or not it got dented in transit or before it was boxed, it should be priority ONE to make sure the pipe gets to its destination with nary a ding or dent. Bad form there.

El Camexican

09-30-2015, 06:53 PM

It never occurred to me that it may have been welded with a gas torch. On a second glance it probably was. I should be able to tell for sure when I look inside the pipe. The reason I assumed it was tig'd is the little pin holes that appear in a few spots (I'm not saying they are through holes) These happen a fair bit when TIG welding mild steel unless you're purging the inside of the pipe. The cause is heated impure air trying to escape as you complete the ring. If you purge the pipe then its full of argon and the weld looks a lot better on the back side as well. I haven't gas welded mild steel with anything but bronze for years, but I don't recall having pin holes like that.

Anyway, I want it made clear that I am NOT complaining about the pipe, or the welds (as long as they don't leak), I'm just showing ya'll what I received. You can be your own judges as to what you would pay for something like this, all I'm really concerned with is how the trike runs.

For the record my last DG pipe came with a pretty large pin hole in it that leaks pretty good. Nobody's perfect.

El Camexican

09-30-2015, 11:38 PM

I looked, it's gas torch welded.

barnett468

09-30-2015, 11:55 PM

.
I was just looking at vintage pipes on line to check out the welds [yes I'm weird] and came across this . . look at how many sections it has . . it looks like an ancoonda has a carbon fiber silencer too . . must have cost a bundle.

http://www.leguidevert.com/_lgv/img_forum/2014/02/304189_2706_1896969-606116456109719-2123771031-n.jpg

onformula1

09-30-2015, 11:59 PM

Wow, I am shocked.

I have seen a few Jemco's and I don't remember them looking like that, I would give them a call and also check with Mike (Oscar Mayer on the boards) he had a pipe built for his son's race quad and said it was great looking.

Those pipes and many others are gas welded, but they are "flowed" meaning no filler rod is used.

If you keep it just MIG the brackets, years ago brackets were gas welded or brazed. Bill's Pipes were the first to MIG weld brackets and got some flack for it many years ago, now it's the norm.

You can just blow that dent out pretty easy, I hope it happened in shipping.

As for the extra spring bracket, I alway run two springs per mount with a piece of real rubber tubing a 1/2" long located dead center it keeps the springs from rubbing and vibrating and adds tension too.

3 Wheel Drive

10-01-2015, 12:08 AM

My Jemco pipe has an large collar too, I guess that's the way they make them. How much did it cost to have a new pipe made? Did you have an option to buy a silencer from Jemco? My DG pipe fit so tight I had to sand the exhaust spigot a bit to make it fit.

http://www.3wheelerworld.com/attachment.php?attachmentid=222239&stc=1http://www.3wheelerworld.com/attachment.php?attachmentid=222240&stc=1

Red Rider

10-01-2015, 01:41 AM

.
I was just looking at vintage pipes on line to check out the welds [yes I'm weird] and came across this . . look at how many sections it has ...An absolutely beautiful specimen! It looks like the work of Jollymoto.

muthey

10-01-2015, 03:34 AM

I have sold many of those exhaust gaskets in the last 6 months but have had to put them on hold for a bit as my work where I make them has been really slow and laid me off job attached. Dont worry they are not gone forever just temporarily until I get a lathe at home

El Camexican

10-01-2015, 07:45 AM

Uff. I was hoping this wouldn't turn into a pipe bashing thread (no pun intended) I recall the packaging was a bunch of cardboard sheet wrapped around the pipe with tape, but it was a month ago and I received a bunch of other things at the same time, so I don't recall the packaging exactly. The pipe went straight into the cab of my truck after that.

The one weld I can see from the inside shows part of the collar staggered from its mate and from the outside you can see that a few of them are offset to each other by well over 1/16", but less than 1/8". The gorgeous welds in the photo Barnett posted (by the way I did see that one before, so you're not the only weird one on here) are the way the welds appear on this pipe on the lengths of the cones, but not on the circumferences. As I look closer there was filler rod used on all of them.

That all said the pipe was $404.58 including shipping and paypal fees, so let's step back for a minute and remember that we get what we pay for. This was not a $900 custom job. Ask Billy what his pipe would have cost had he charged himself minimum wage and materials :lol:

On F1: I picked up a cheap little TIG/Stick machine the other day, so MIG, Stick, Oxy Acetylene are all options now:Bounce

3WD: I told him I planned to use my DG silencer and provided the dimensions for the collar, have not tried to fit it yet though.

another

NEWDUCK

10-01-2015, 11:52 AM

This guy builds amazing pipes. His website is down for right now but its mike at cpi racing. For future reference :D
http://backcountryrebels.com/attachment.php?attachmentid=20566&stc=1&d=1299772079

Someone hand built the pipe on my Z. I think it really hurts performance all around. One day Ill buy a stock or dg to replace it. Ill have to get some pics of it. Awesome build btw!

barnett468

10-01-2015, 05:34 PM

Uff. I was hoping this wouldn't turn into a pipe bashing thread (no pun intended)
Well, if it was shipped by UPS, they can in fact screw up a ___ dream . . I paid almost $2,000.00 for a NOS hood for my 69 Boss 302 and it was still packed in the orig Ford shipping box, and when it arrived, it looked like it was dropped off a 10 story building...and then run over . . Luckily I had it insured for full value but it was a hassle getting the money back.

As I look closer there was filler rod used on all of them.

I have watched Harry Klemm and my other friend Lee Scheffers make pipes and they both used some filler rod . . Simply butt welding a pipe makes the area thinner and weaker.

That all said the pipe was $404.58 including shipping and paypal fees...

Screw the ugly welds, that's still a pretty good deal these days as you mentioned.

...so let's step back for a minute and remember that we get what we pay for.

Well I gave her $20.00 on felt I only got $7.53 worth.

(by the way I did see that one before, so you're not the only weird one on here)

Oh goodie, does that mean we can talk about oil now? . . Your exhaust flange might slip on easier and be more resistant to corrosion and seizing if you use some, especially if it has high levels prefabulated amulite...
.

ironchop

10-01-2015, 05:47 PM

Yeah you might have mentioned the price first so we had some context.

I was wondering why he didn't sand off the fisheye pinholes.

That's actually a better deal than I gave it credit for .

That being said, pull that dent out. Its still ruining it for me :)

Sent from my Z998 using Tapatalk

El Camexican

10-01-2015, 06:44 PM

I'll get on that dent Chop Chop:lol:, but first I need to find a three prong 220V single phase plug for my TIG welder. Should be common as perro caca but I'm being told 4 to 5 weeks to get one in the industrial mecca of all of Mexico, WTF??? You guys that can mail order a hood (dented or not) to your front door have no idea how good you have it...

barnett468

10-01-2015, 06:54 PM

You guys that can mail order a hood (dented or not) to your front door have no idea how good you have it...

Hey EL . . actually we do know just how good we've got it, that's why we choose to live in the US instead of "Southern California". :lol:

onformula1

10-01-2015, 08:44 PM

ironchop

10-01-2015, 09:14 PM

I can't believe you can't hammer out three blades, jb weld the wires to the blades, and carefully plug it into the wall.

That's what a real Mexican would do ;)

Sent from my Z998 using Tapatalk

El Camexican

10-01-2015, 10:25 PM

I can't believe you can't hammer out three blades, jb weld the wires to the blades, and carefully plug it into the wall.

That's what a real Mexican would do ;)

Sent from my Z998 using Tapatalk

There you go OnF1, that's exactly why there are none at Home Depot, or anywhere else down here. A Mexican shop worker will cut off the plug of ANYTHING. For 110V they twist the wires and stick them in the slots, for 220V then they fray and flatten the wires and stick them into the clamps that hold the fuses in place in the box.

I will be at a suppliers tomorrow and try to snap a photo for you. When I painted my trailer there the compressor didn't have a pressure sensor/switch (or an on off switch) on it, so I would stick the wires into a high voltage box, sparks would fly till the wires welded themselves to the fuse clamps and I would run back to the spray gun and paint as fast as I could to try and keep the tank from getting over 100psi then when the cup ran dry I'd run back to the box and pull the wires out before refilling the gun. Keeps you on your game.:lol:

JB Weld? You jest!

onformula1

10-01-2015, 11:43 PM

Can I just ship you one? UPS, Fed-ex, USPS?

I never tried to ship to Mexico, they must have shipping correct?

ironchop

10-02-2015, 09:56 AM

They steal everything out of the mail ......it`s a joke......insurance and maybe it gets delivered !

you must be talking about the UPS hub in Nashvegas Tennessee.

Many a firearm part or Vintage chopper part I have sent or received has completely disappeared in the Brown Triangle down there never to be seen again. The claims lady and I were on a first name basis in `06.

are you all electric, Camexican?

If so, just steal the plug off your dryer or stove while your wife is out....that's what I would do. Then play stupid when she gets home and claims "you should have known better"

That's the speech I got last week for baking rattle can paint jobs in the kitchen oven

onformula1

10-02-2015, 12:45 PM

you must be talking about the UPS hub in Nashvegas Tennessee.

Many a firearm part or Vintage chopper part I have sent or received has completely disappeared in the Brown Triangle down there never to be seen again. The claims lady and I were on a first name basis in `06.

are you all electric, Camexican?

If so, just steal the plug off your dryer or stove while your wife is out....that's what I would do. Then play stupid when she gets home and claims "you should have known better"

That's the speech I got last week for baking rattle can paint jobs in the kitchen oven
On the oven, been there done that, got busted so, I grabbed a oven off the street on bulk trash day and fixed it for the shop, I also found a large toaster oven for the small stuff.

I built a hanging system for both to.

Happy wife, happy life.

Sent from my SM-G386T1 using Tapatalk

El Camexican

10-02-2015, 06:11 PM

Can I just ship you one? UPS, Fed-ex, USPS?

I never tried to ship to Mexico, they must have shipping correct?

Thanks for the offer, but I ordered the plug yesterday on ebay for less than 1/3 of the price here. I'll run up next week and grab it.

Glamy seems to have used the Mexican Postal Service before:lol: They open everything and send on only what they deem to have no value. When I got married the only gift that made it here was a card. I swear if you shipped a pig they'd even steel the squeal!

Most of the time they don't even reseal the envelopes and boxes, so if it does make it past Customs it can still get lost. It can also take more than 6 months to get a letter by mail. I've lost count of how many times I've had to go an pay a reactivation fee for my phone, gas, or power because the bill never came, or came 3 weeks after the cut off date.

There are services that will bring stuff down her for a fee that are reliable likely because there are greasing palms all the way down here, but they are by subscription, so I don't bother and just use our US warehouse address and pick things up myself.

Here's a power box I saw today. OSHA anyone?:lol:
222281

El Camexican

10-03-2015, 12:03 AM

I like view out the hole .....um window the best !

I think it's a false wall.

fieldy

10-03-2015, 12:46 AM

El Camexican

10-03-2015, 07:04 AM

It ain't humid but it sure is hot........down in Mexico......riff raff......
looks like someone done stole the ac for the metal, nice hard hat, safety first!...........let's hear it for the man! Cool bike!
Maybe someone tied a rope to the bars and took off leaving the huge hole like many a mexican western picture show.

It' pretty humid where I am and pretty hot too.

Truth be know that half wall is a pretty common feature down here. The key to beating the heat is a high roof and air movement, so most welding shops have cement walls about 8 to 10 feet high and then a steel roof on columns another 10 feet above that. They may add chain link to the void if it's exposed to a street. This particular shop is on a huge parcel of land owned by one guy that converted it from a dairy farm to a complex that contains over 6 businesses. That short wall is part of the original farm which now separates the shop from a pallet manufacturer. If you send enough time down here you don't even give walls and wiring like that a second glance.

onformula1

10-03-2015, 05:53 PM

Nico, check your email, thanks

barnett468

10-03-2015, 06:07 PM

Truth be know that half wall is a pretty common feature down here. If you send enough time down here you don't even give walls and wiring like that a second glance.

Yup...looks pretty much the same inside police headquarters in Rosarito Beach. http://www.mustang.org.au/forum/Smileys/smilies/hysterical.gif

El Camexican

11-01-2015, 10:18 PM

Finaly got the pipe on. Muthey's collar worked great, the only thing I had to do to make it fit perfectly was sand the burr off the Jemco flange and open up the collar to the same size as my ported hole.

Sounds awesome! With the pipe and all the mods the Tri-Z "sound" is gone, I love it! Started with a 48 pilot and a 170 main. Once warm it became pretty obvious that a couple sizes down on each is needed before I bother to take it for a rip.
223434

I found someone to cut my swing-arm, so that's the next step. Plan is to add 3.99" to make sure it stays in the mod class at TF :acr
223435

onformula1

11-01-2015, 10:53 PM

jeswinehart

11-01-2015, 10:58 PM

El, you're coming too TF2016 ???

El Camexican

11-01-2015, 11:37 PM

Chop, chop choppy!

I checked my specs I think you are very close on the pilot maybe a 45, but I think you will end up with about a 162 main jet. (165 second guesstimation)

PWK 38mm correct?

Yep, 38 PKW. Blue "JD" needle from a 250 KTM, #7 slide, pod filter, stock steel reeds, float height at 16mm and 1.5 out on the air screw to start. She came off the choke pretty fast and smoked pretty heavy when warm. It sings up super fast from idle, but starts to blubber a fair bit as she nears the top. In saying that it sure seems to rev a lot higher than it used to. The thing sounds more like a 125 that a 250 when the throttle is stabbed in neutral. I love it!:p

El Camexican

11-01-2015, 11:48 PM

El, you're coming too TF2016 ???

Yea, it's a 99.99% done deal ( I hate saying 100% in case something comes up). I had planned to go this year, but totally screwed up the date when coordinating a trip my wife was planning and told her to buy her tickets for the day TF 2015 was ending:rolleyes: Given the rain I guess I was lucky. Anyway, I won't make that mistake for 2016. Really looking forward to it:Bounce Planning to bring 2 trikes, 1 big bottle of rum and a 1/2 dozen cigars. Food, shelter and other luxuries I'll figure out when I get there. Slept in my truck cab for three seasons of drag racing, I can do it again for one week.:lol:

onformula1

11-02-2015, 12:02 AM

Yep, 38 PKW. Blue "JD" needle from a 250 KTM, #7 slide, pod filter, stock steel reeds, float height at 16mm and 1.5 out on the air screw to start. She came off the choke pretty fast and smoked pretty heavy when warm. It sings up super fast from idle, but starts to blubber a fair bit as she nears the top. In saying that it sure seems to rev a lot higher than it used to. The thing sounds more like a 125 that a 250 when the throttle is stabbed in neutral. I love it!:p

Stock steel reeds???

They were bad in 1985...:lol:

onformula1

11-02-2015, 12:06 AM

Yea, it's a 99.99% done deal ( I hate saying 100% in case something comes up). I had planned to go this year, but totally screwed up the date when coordinating a trip my wife was planning and told her to buy her tickets for the day TF 2015 was ending:rolleyes: Given the rain I guess I was lucky. Anyway, I won't make that mistake for 2016. Really looking forward to it:Bounce Planning to bring 2 trikes, 1 big bottle of rum and a 1/2 dozen cigars. Food, shelter and other luxuries I'll figure out when I get there. Slept in my truck cab for three seasons of drag racing, I can do it again for one week.:lol:

I would love to go to trikefest, 26 hours one way is a long drive!

El Camexican

11-02-2015, 12:36 AM

I would love to go to trikefest, 26 hours one way is a long drive!

Longer for me I think.

Yea, went with steel reeds for the stiffness hoping to get a few more RPM out of the engine. The stops are opened to as large as the cylinder will allow. I have a set of Boyesen's but want to try the steels first.

onformula1

11-02-2015, 12:47 AM

Longer for me I think.

Yea, went with steel reeds for the stiffness hoping to get a few more RPM out of the engine. The stops are opened to as large as the cylinder will allow. I have a set of Boyesen's but want to try the steels first.

The steel reeds will flutter before you ever see any of the new found power from mid to top.

El Camexican

11-02-2015, 01:10 AM

The steel reeds will flutter before you ever see any of the new found power from mid to top.

Good point. They will get one test before the fibers go back in.

onformula1

11-02-2015, 01:23 AM

Good point. They will get one test before the fibers go back in.

They will be much better and will not flutter, but they will float a bit.

In the end I will predict you will end up with carbon fiber high tension reeds.

El Camexican

11-02-2015, 01:30 AM

They will be much better and will not flutter, but they will float a bit.

In the end I will predict you will end up with carbon fiber high tension reeds.

I think that would require the V-Force set-up. I was really hoping to avoid that. Do you know of a CF reed that fits the stock Tri-Z cage?

onformula1

11-02-2015, 02:07 AM

I think that would require the V-Force set-up. I was really hoping to avoid that. Do you know of a CF reed that fits the stock Tri-Z cage?

Carbon Tech reeds-

http://www.carbontech.com/motor/yamaha.html

88-92 YZ125 part number- 144HT (Same as a Tri-Z) $54.95

I like this set-up over the V-Force, less money too.

onformula1

11-02-2015, 02:16 AM

You could use Boyesen carbon fiber reeds for the same application if you want, I like the Carbon Tech reeds better and have been using them since 1993, what's interesting is Boyesen is now selling Carbon Tech reeds on their website, that seems a bit strange to me?

cr480r

11-21-2015, 05:16 AM

Still some tdr carbons out there floating around. I have a set in mine. Got em for like $15

El Camexican

11-21-2015, 11:24 AM

barnett468

11-22-2015, 06:02 AM

.
Hey El, glad to hear you got it running . . I'm not sure how much you know about dirt drag racing, and I am certainly not the foremost authority on it, but I posted some stuff that might be helpful, some of which you probably know but I figured I'd cover the bases anyway just in case.

Also, you might consider starting a separate thread for drag racing titled something like "What is the best tire and suspension setup for Trike Fest Drag Racing" because I think you will get more answers simply because more people will see it.

CHAIN

I would run the RK 520 MXZ4 chain . . It is one of the lightest available and should be good for another hp or two . . It comes in all the colors of the rainbow . . If you don't trust master clips you can use the rivet type.

http://rkexcelamerica.com/products/brands/rk/japan-chain/rk-520-mxz4-dirt-bike-chain

SUSPENSION VS TRACTION VS WHEELIES

A bouncing bike is a bad thing.

Wheelie bars can help but people have won without them.

I would try it with lower suspension to reduce the potential for wheelies but the lower it is the less traction you will have, so you might want to test it with stock height and lowered.

REAR - I would lower it around 2 1/2 to 3 inches from stock and check the fender to tire clearance when bottomed and install a spacer on the shock shaft between the bottoming bumper and the shock if needed . . You can use cheap aluminum to reduce weight and reduce the chance of scratching the shaft and it needs to be almost the same diameter as the shock body . . You can just use a tie down to pull down on the suspension which will obviously make it a bit stiffer which "should" also help . . Try it with the damping settings on max.

If you use the 4 Snow type tire, they will bounce, so you might also try removing the shock and installing a solid bar . . You could even make it adjustable inexpensively by using a swedge tube and heim rod ends . . This will also reduce the bike weight by maybe 6 lbs . . If you do this, just remember to use 1 right hand thread and 1 left hand thread joint.

FRONT - Lower this by the same amount, but if it gets twitchy at high speed, raise it up until it is at the best setting.

If you don't have air caps or do but don't want to mess with air, preload the front springs around 1 1/2" and run 20 wt fork oil.

TIRE PRESSURE

Try it low and try it high . . Any change less than 3 lbs will be hard to notice so I wouldn't bother with 1 lb increments . . This will save you some testing time.

TIRE TYPE

I see you have been doing your homework . . This being said, the winners in 2014 were running Ohtsu Pro Wedge II's . . They work better than the snows in harder packed dirt and are what a lot of the drag guys I know are running but they them backwards . . Unfortunately they are only available used so Ebay is one place to find them . . There is a set on there now.

I'm guessing you checked out the 2014 Trike Fest drag videos but if not, you can see 3 top bikes in the one below and they all have Ohtsu Pro Wedges.

https://www.youtube.com/watch?v=PRSInzPgV_Q

RIM TYPE AND RIM WIDTH

I would consider using the 10" wide .125 Mitchell's with them . . They will have reduce expansion and bounce and increased contact area over using them on 9" wide rims.

IGNITION TIMING

I wouldn't worry about adjusting the timing for better bottom end since you will only be running at top end at the drags and the more rpm the merrier . . As long as your timing is not too far advanced, the more you run, the more power it will have so basically, if it doesn't ping now, retarding it will make it richer and reduce power everywhere including on the bottom . . I would set it until it revs the highest, then retard it 2 degrees so you have a margin of safety . . Basically, if you are running stock timing, it likely does not have enough advance but this depends on the rate your fuel burns also, so you should time it with the fuel you will be using.

I would also get a tach and possibly a detonation sensor . . You can get digital tachs as cheap as $10.00 but of course it is a $10.00 tach.

Tach

http://www.ebay.com/itm/Hour-Meter-Tachometer-For-Outboard-Mercury-Yamaha-Nissan-Evinrude-2-4-Stroke-/360845036042

Your ignition also may not provide enough advance and if you get a programmable one, you can set it to the optimum level . . PVL might have one but MSD does for sure . . It is $300.00.

https://www.mpsracing.com/instructions/MSD/4217.pdf

REAR AXLE BEARINGS

I would consider some low friction ones . . They are a bit pricey but they will last a long time and are good for a couple hp . . Ceramic bearings are even better but are expensive and not necessary for your app since you aren't running a Honda . . Some places like Applied Tungstenite can coat your bearings . . Check with the places below for info.

http://www.appliedtungstenite.com/html/bearings.html

http://www.microblueracing.com/microblue-steel-ball-bearings.html

COOLANT

This is a long and complicated subject, but in short, one aspect of anti freeze is that it is around 3 times more viscous [thick] than water, so it puts more load on the water pump which in turns eats a little more hp but not a very much . . I would consider running 15 % antifreeze and some water wetter type liquid but a different brand like Purple Ice and the rest distilled or purified water but tap water wont hurt.

I would also run a slightly higher pressure rad cap . . Rocky Mountain ATV has them.
.

El Camexican

11-22-2015, 11:25 AM

Oh my, here goes, not sure if the skin on my finger tips is thick enough thou...

.CHAIN

I would run the RK 520 MXZ4 chain . . It is one of the lightest available and should be good for another hp or two . . It comes in all the colors of the rainbow . . If you don't trust master clips you can use the rivet type.

I know you meant to say "free up another hp or two" so I won't tease you about it. Already ordered a KTM non-o-ring orange chain. I'm 99% sure it's made by RK. I bought it for the color, otherwise I would have bought a D.I.D. Saw you comment that they were a "decent" chain the other day. My D.I.D. ERV3 chains go 3,000 miles without needing a single adjustment on steel sprockets. So far I've been selling them for $50 bucks to others when I change my counter sprockets and put a new chain on. If I was concerned about breaking a chain I would buy an EK. They make a 630 that can handle over 1000hp stuck to a slick.

SUSPENSION VS TRACTION VS WHEELIES

A bouncing bike is a bad thing.

Wheelie bars can help but people have won without them.

I would try it with lower suspension to reduce the potential for wheelies but the lower it is the less traction you will have, so you might want to test it with stock height and lowered.

REAR - I would lower it around 2 1/2 to 3 inches from stock and check the fender to tire clearance when bottomed and install a spacer on the shock shaft between the bottoming bumper and the shock if needed . . You can use cheap aluminum to reduce weight and reduce the chance of scratching the shaft and it needs to be almost the same diameter as the shock body . . You can just use a tie down to pull down on the suspension which will obviously make it a bit stiffer which "should" also help . . Try it with the damping settings on max.

If you use the 4 Snow type tire, they will bounce, so you might also try removing the shock and installing a solid bar . . You could even make it adjustable inexpensively by using a swedge tube and heim rod ends . . This will also reduce the bike weight by maybe 6 lbs . . If you do this, just remember to use 1 right hand thread and 1 left hand thread joint.

FRONT - Lower this by the same amount, but if it gets twitchy at high speed, raise it up until it is at the best setting.

If you don't have air caps or do but don't want to mess with air, preload the front springs around 1 1/2" and run 20 wt fork oil.
Wheelie bars are not allowed in the mod class as far as I know. Unfortunately my 4" swing-arm extension is going to raise my rear end and my front forks are dropped about about 1.5" as I have a slight bend in the tubes that I have positioned to straighten out over time (I hope). I was thinking of strapping the rear down 3 or 4 inches if they will allow it. BUT, I am also thinking that having the ass high without a wheelie bar, or 8" over swinger may be an advantage out of the hole as it will allow a little more wheel spin.

The constraints of this class tell me that it's all about the clutch and who can get to third gear first without lifting the front wheel too high. As far as top end stability as it relates to the stance of the chassis I don't think the speeds reaching in this competition will cause it to be an issue. I'm guessing 50 - 60 MPH would be the highest I'd get to. I have a Works rear shock build to my weight and a set of Progressive springs up front and do have air caps. Should be overkill for a drag racer. Hopefully the swing-arm extension won't fudge the rear too much, but if it does I can send the shock back to them with the new specs.

TIRE PRESSURE

Try it low and try it high . . Any change less than 3 lbs will be hard to notice so I wouldn't bother with 1 lb increments . . This will save you some testing time.

TIRE TYPE

I see you have been doing your homework . . This being said, the winners in 2014 were running Ohtsu Pro Wedge II's . . They work better than the snows in harder packed dirt and are what a lot of the drag guys I know are running but they them backwards . . Unfortunately they are only available used so Ebay is one place to find them . . There is a set on there now.

I'm guessing you checked out the 2014 Trike Fest drag videos but if not, you can see 3 top bikes in the one below and they all have Ohtsu Pro Wedges.

https://www.youtube.com/watch?v=PRSInzPgV_Q

RIM TYPE AND RIM WIDTH

I would consider using the 10" wide .125 Mitchell's with them . . They will have reduce expansion and bounce and increased contact area over using them on 9" wide rims.

IGNITION TIMING

I wouldn't worry about adjusting the timing for better bottom end since you will only be running at top end at the drags and the more rpm the merrier . . As long as your timing is not too far advanced, the more you run, the more power it will have so basically, if it doesn't ping now, retarding it will make it richer and reduce power everywhere including on the bottom . . I would set it until it revs the highest, then retard it 2 degrees so you have a margin of safety . . Basically, if you are running stock timing, it likely does not have enough advance but this depends on the rate your fuel burns also, so you should time it with the fuel you will be using.

I would also get a tach and possibly a detonation sensor . . You can get digital tachs as cheap as $10.00 but of course it is a $10.00 tach.

Tach

http://www.ebay.com/itm/Hour-Meter-Tachometer-For-Outboard-Mercury-Yamaha-Nissan-Evinrude-2-4-Stroke-/360845036042

Your ignition also may not provide enough advance and if you get a programmable one, you can set it to the optimum level . . PVL might have one but MSD does for sure . . It is $300.00.

https://www.mpsracing.com/instructions/MSD/4217.pdf

REAR AXLE BEARINGS

I would consider some low friction ones . . They are a bit pricey but they will last a long time and are good for a couple hp . . Ceramic bearings are even better but are expensive and not necessary for your app since you aren't running a Honda . . Some places like Applied Tungstenite can coat your bearings . . Check with the places below for info.

http://www.appliedtungstenite.com/html/bearings.html

http://www.microblueracing.com/microblue-steel-ball-bearings.html

COOLANT

This is a long and complicated subject, but in short, one aspect of anti freeze is that it is around 3 times more viscous [thick] than water, so it puts more load on the water pump which in turns eats a little more hp but not a very much . . I would consider running 15 % antifreeze and some water wetter type liquid but a different brand like Purple Ice and the rest distilled or purified water but tap water wont hurt.

I would also run a slightly higher pressure rad cap . . Rocky Mountain ATV has them.
.

Tire pressure will be have to be set for each type of condition. I've been trying to think of a place here where I can test it properly. Most flat terrain here is hard packed like a gravel road.

I have a $30 tach I plan to hook up. I can attest to the $10 eBay ones not working and not covered by warrantee.

Timing changes will have to be tuned to fuel as you say. I still haven't found any one that wants to sell me some C12 down here and I can't ship it to our warehouse in the States because OSHA recently raped us and all fuels are stored outside.

Rims are 9 or 10" ITC, I'm not planning to change them.

Stock rad cap stays, I'd rather piss it out the overflow tube than the head gasket.

Coolant is 75% water

Ceramic bearings, adjustable ignition curves and detonation sensors are all way out of the budget I'm willing to give this thing. If winning at all cost was the issue I would be posting about fitting a single front wheel to a nitro sand rail. Not happening! Would I like to win the mod class? Hell yea! Will I? I doubt it, I'm probably going to get smoked by someone on a bone stock wore out Tecate, but it would be nice to be the quickest Tri-Z with under 250cc's pulling it.

barnett468

11-22-2015, 05:51 PM

.
Ok, then as your primary question regarding the tires goes, the 4 SNOW's certainly aren't a "bad" choice at all then, and I would get 20x10x9's if I used them, but here's a bit more info.

In 2012, one of the top bikes used the Duro HF245 20x11x10 in the photo below.

The Ohtsu Pro Wedge hook up a bit better than the 4 Snows on hard packed dirt like the Trike Fest track has.

Lots of drag racers also use the Ohtsu MR 501's and Dunlop KT335's on dirt like Trike Fest has.

My point being that there are a few different types of tires that will be highly competitive in case you wanted to tun something other than the 4 SNOW's there.

Pro wedge II ........ 11.8 .. 22x11x8 . . Discontinued
MR 501 ............... 13.2 .. 20x10x9 . . Last used on 2012 400xX & 400EX so may still be available . . p/n 42711-HN1-004?
Dunlop KT335 ..... 14.4 ... 2-x10x9 . . Discontinued but some shops may still have
4 SNOW approx ... 15.0 .. 22x10x8 . . Available
Duro HF245 ............. ? .. 20x11x10 . They also make 20x11x9 . . Available.
Duro Sand and Snow . . This is nearly identical to the 4 Snow's tread, but I don't know anything about it

These Ohtsu MR 501's are purportedly new and this may be the last new pair one will ever see, because if they aren't already discontinued, they most likely will be soon . . There may also be a date of mfg on tire . . $190.00 plus shipping.

http://www.ebay.com/itm/OHTSU-20x10X9-Tire-Set-OEM-Honda-TRX400EX-TRX250R-TRX450R-TRX400X-/291498594381

Used Ohtsu Pro Edge II's . . These look very good but ask about sidewall cracking . . This ad just ended and they did not sell, but I have an Ebay account and can contact the seller if you want . .$100.00 with aluminum Honda rims.

http://www.ebay.com/itm/Hondaline-Ohtsu-Pro-Wedge-II-2-Paddle-Mud-Snow-Tires-4x110-Vintage-NICE-/201447652132?nma=true&si=7kn4pJyqliHB3Io32q7O1vyL8Jo%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

OHTSU MR 501

http://i.ebayimg.com/images/i/291498594381-0-1/s-l1000.jpg

DUNLOP KT335

...... https://images.rockymountainatvmc.com/images/prod/275/d/dun_07_kt_335_rea.jpg

DURO HF245

http://cdn1.bikebandit-images.com/product_images/du/450/duro-hf245-atv-tire.jpg

onformula1

11-22-2015, 07:31 PM

I installed a set of new Boyesen reeds last week, dropped the pilot to a 45 and the main to a 162.

Still seems a little fat at the bottom, but it cleaned up a lot at the top. If I had to guess I would say retarding the timing a couple degrees may be all that is needed. If not them I guess CF reeds will be needed.

The swing-arm is half done and waiting on some other projects to be finished, but by years end I expect to have the swinger installed with a 48T rear and a non-o-ring chain. I need to get the longer brake line ordered as well.

Still debating a set of 4 SNOWS. Any opinions would be appreciated based on this thing being used at the drags only.

TF is only 7 months away, time sure seems to fly.

Since the Pro Wedges are hard to come by and most after 30 years are cracked, I would run the best replacement the 4 Snow

http://www.maxxis.com/catalog/tire-363-4-snow

They are light, 2 ply, have killer traction and are 22" tall which is what you want for the drags.

The longer swing arm will need a stiffer spring due to leverage and chain torque. (Contact me, I will help you out)

You may consider running AVgas in Mexico until you can buy fuel in the USA, I have a few sand drag racing friends in Mexico that run it with fantastic results. Because of the nature of a airplane that fuel in equal in quality to US standards. Look for 100LL I have been told it is called "Azul" in Mexico. (Check with the airport to be sure)

Don't worry about the chain there have been dyno tests performed where the best non o-ring chain vs. the worst o-ring chain was less than 1/5 of 1 horsepower.

On a 2 stroke-
Retarded timing= more upper mid, top end & over rev

Advanced timing= more low end and mid

As for jetting- don't forget what your launch RPM will be.

El Camexican

11-22-2015, 09:53 PM

The longer swing arm will need a stiffer spring due to leverage and chain torque. (Contact me, I will help you out)

When the swinger is completed I'll shoot you an email with the numbers.

I will find that C12, I just need to get off my butt.

cr480r

11-22-2015, 11:13 PM

You may consider running AVgas
I ran a lot of 100ll successfully in my old lt250. I don't remember the comp ratio anymore, but it trapped 215psi with a 190 port.

Don't worry about the chain there have been dyno tests performed where the best non o-ring chain vs. the worst o-ring chain was less than 1/5 of 1 horsepower.
I bought DID ERT2 once thinking it was gonna gain performance. The chain was garbage after one dune trip.. Been using sealed chain every since.

onformula1

11-22-2015, 11:52 PM

When the swinger is completed I'll shoot you an email with the numbers.

I will find that C12, I just need to get off my butt.

Ask Pedro Gonzales.

onformula1

11-22-2015, 11:56 PM

I ran a lot of 100ll successfully in my old lt250. I don't remember the comp ratio anymore, but it trapped 215psi with a 190 port.

I bought DID ERT2 once thinking it was gonna gain performance. The chain was garbage after one dune trip.. Been using sealed chain every since.

O-rings rule in the dunes.

Where have you been, kinda quiet on this forum lately, no?

86T3

11-23-2015, 02:55 AM

Most of the heavy hitters in open are running 4 snows. I bought a set for my T5 but didn't get much testing done because 1) I finished the build there 2) We had to jet it 3) a couple hangovers of epic proportion and lastly 4) the monsoon. The few runs I made they hooked really well but we're a little too tall for my already tall gearing, si if you go this route I'd bring some different sprockets to try. And don't be the last person at the Choo tree

barnett468

11-23-2015, 03:00 AM

Don't worry about the chain there have been dyno tests performed where the best non o-ring chain vs. the worst o-ring chain was less than 1/5 of 1 horsepower.

El, as you may know, just because one dyno test may have shown only 1/5 th of 1 hp difference in the test mentioned, it doesn't mean that it is not possible to gain more than that by using different chains then the ones they tested . . There may have also been errors in their testing method . . I have seen errors in various testing methods dozens of times before . . Tests are only valid if they are repeatable, and the fact is that it is absolutely possible to "free up" more than a paultry 1/5th hp by using a lighter chain and contrary to what has been implied by some [or one] the amount of gain I mentioned absolutely is achievable in some instances.

In addition, power can not only be gained by using a light chain as opposed t a heavier one, the lighter chain also reduces the weight which in turn increases the power to weight ratio . . Obviously the amount of change in this instance would be extremely small and therefore not worth "worrying" about in your particular case, it does exist as you know, and in some cases at Kawi such as the works MX and Road Race bikes, we actually spent a LOT of time and money per ounce reducing a vehicles weight.

Having also seen many dyno tests, including ones we did at Kawasaki, I can say for a fact that it is nearly impossible to accurately determine the cause of such a small difference in hp because of other variables such as engine temp and dyno error and operator error etc. One thing that must be done when trying to determine the cause of such a small difference in hp is to use a sealed, climate controlled dyno room where the temperature and humidity can be controlled . . The atmospheric pressure also affects hp and it can change enough from morning to afternoon to cause a slight difference in hp, however, most dynos are able to correct the hp numbers based on the different factors IF the dyno operator puts them in.

I have seen several cases where a dyno operator simply entered incorrect factors which were then shown on the dyno sheet . . This is actually not a big problem if one is only using the dyno for a comparison test between different parts or settings, however, if the same bike is run on the same dyno under the same conditions but the operator then uses the correct correction factors, the bike will miraculously appear to have either gained or lost hp . . Also, the readings from wheel dynos are not as consistent as the ones from engine dynos because different tire pressure will alter the hp rating.

For these reasons as well as others, it is sometimes best to get try and find info from an another source when one looking for something just to see if both sources say a similar thing . . Obviously there are several mfg's that say their product is better than everybody else's and in some cases they even say it has been "proven" to be by an "independent" lab, but I think that most of us know that Dos Equis really is much better than Corona. :)

Here's a dyno test where all they did was oil the chain and they "freed up" 10 more hp, so heck, just oil yer chain and grease yer bearings and ya might "free up" as much as 15. http://www.mustang.org.au/forum/Smileys/smilies/thumbsup.gif

:beer

http://www.webbikeworld.com/t2/bmw-scottoiler/

http://www.webbikeworld.com/t2/bmw-scottoiler/scottoiler-gear-dyno-test.jpg

Billy Golightly

11-23-2015, 10:00 AM

El Camexican, Glad to hear you will be at TF this upcoming year! It is an experience you wont likely forget!

El Camexican

11-23-2015, 08:42 PM

Ask Pedro Gonzales.

Already asked Sr. No dice. :(

El Camexican

11-23-2015, 08:44 PM

El Camexican, Glad to hear you will be at TF this upcoming year! It is an experience you wont likely forget!

I'm pumped man, is is going to be a blast!!! I figure if I have just one drink with each of the people I hope to meet... I'll be drunk.:beer

onformula1

11-23-2015, 09:25 PM

Already asked Sr. No dice. :(
I wonder what they run?

Sent from my SM-G386T1 using Tapatalk

El Camexican

11-23-2015, 10:19 PM

I wonder what they run?

Sent from my SM-G386T1 using Tapatalk

Good question. I didn't ask, but I assume Pemex "roja" like the rest of us. There are guys that have it here that have race fuel, the problem is getting it without a connection.

Jmoozy27

11-23-2015, 10:37 PM

Good question. I didn't ask, but I assume Pemex "roja" like the rest of us. There are guys that have it here that have race fuel, the problem is getting it without a connection.

A lot of people have died or been injured producing and refining that fuel. Pemex safety policy is like that of the Panama Canal trenchers. :lol:

86T3

11-23-2015, 10:58 PM

I'm pumped man, is is going to be a blast!!! I figure if I have just one drink with each of the people I hope to meet... I'll be drunk.:beer

And then you don't get any tire testing done

barnett468

11-23-2015, 11:20 PM

And then you don't get any tire testing done

hmmm...should I beer test, or tire test...beer...or tire . . I think I'll have another beer while I think about it.

barnett468

11-23-2015, 11:34 PM

.
Hey El, if you drink enough, you could probably run these on the back and it wouldn't make much difference.

.......OATSUE TRACTION MASTER EXTREME IV

. . . . https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcToehxHtQhWXjzEQdE0dOZFevvFouOxD VLk08H3sXHCF5iwzskj

El Camexican

11-23-2015, 11:44 PM

A lot of people have died or been injured producing and refining that fuel. Pemex safety policy is like that of the Panama Canal trenchers. :lol:

I believe you guys refine a lot of it. Fortunately you save all the ethanol for yourselves:) It's dirty as all heck due to the storage systems here, but as long as you run a filter it burns great. I always topped my street bike up with it before trailering it the Hill Country to ride the Twisted Sisters up north. Seemed to run much better than on TX premium with 10% ethanol.

El Camexican

11-23-2015, 11:56 PM

And then you don't get any tire testing done

No worries, I don't drink till the sun sets. I love to drink and I love to drive, but I hate doing both at the same time. Hope to see you there. We can talk about your Sabers;)

barnett468

11-24-2015, 12:22 AM

No worries, I don't drink till the sun sets.

Yes but I think that not stopping until it rises again might make racing a little bit challenging.

El Camexican

11-24-2015, 12:53 AM

Yes but I think that not stopping until it rises again might make racing a little bit challenging.

It does! I crashed one morning doing a burnout in front of a large crowd once while my liver was still working on cleaning my blood up. Loosened my steering head bearings (guess the races weren't properly seated) Next pass ended up being a 110mph tank slapper. That one sobered me up!:lol:

onformula1

11-24-2015, 04:50 AM

Might want to get this-

http://www.scottsonline.com/Stabilizer_Photos.php?ID=1191

keister

11-24-2015, 01:41 PM

Yea, it's a 99.99% done deal........... Planning to bring 2 trikes, 1 big bottle of rum and a 1/2 dozen cigars. Food, shelter and other luxuries I'll figure out when I get there......
Stop the presses!! That is awesome news!!

Most of the heavy hitters in open are running 4 snows.
Actually, I think they are called '3-Snows'.

..........3) a couple hangovers of epic proportion ........ And don't be the last person at the Choo tree
If we're gonna be best friends, you're gonna need to man up

barnett468

11-24-2015, 06:50 PM

On a 2 stroke-

Retarded timing= more upper mid, top end & over rev

Advanced timing= more low end and mid

This statement is a little vague to me at least and therefore would be more helpful if a more detailed explanation or a link to the source of the info is posted so I and others that might not understand it could better understand it.

I am definitely not as knowledgeable about ignition timing as many people, but in general, part of my experience and understanding of it is that it is not completely accurate that "advanced timing" timing increases bottom end power but "retarded timing" increases top end power etc, however, it is certain that each individual engine determines exactly how much timing it wants and at what rpm it wants it, at least this is the way it has always been in the past.

The ideal time to have the spark occur is when it is timed to cause the combustion to create the most pressure in the cylinder . . This is referred to as the location of peak pressure or LPP . . The point at which the combustion makes peak pressure will always be after top dead center, however, it will not always be at the same point relative to the crank angle/piston location . . The more the ignition timing is advanced towards its optimum point for a particular engine, the higher the cylinder pressure becomes and the closer to top dead center the LPP becomes . . None of the people whom have done the LPP test and wrote articles I read by them regarding their findings are certain just why this location changes.

Unless one has the sensors to determine the exact LPP of every engine vs the point at with the spark plug fires relative to the crank angle/position of the piston, one has to resort to alternative methods to determine it as closely as possible . . One of the options to determine the LPP, which will also get the engine to produce the maximum hp and tq throughout the entire rpm range, is to test different timing settings at different rpm's on a dyno and then modify the computer program on engines that have computer controlled ignition, or modify the mechanical advance unit and change the distributor or timing plates position on engines that don't have computer controlled ignition timing so they provide timing settings that are close to the best dyno test settings found as possible . . The timing curve can be set more accurately with computer controlled ignitions than it can on ignitions that only use a mechanical advance unit to control them.

Another one of the options to achieve maximum power is to advance the timing until the engine begins to detonate slightly then retard it a little so there is a safety margin . . I add the safety margin because the greater the load on the engine, the greater the potential there is for it to have detonation, and there may be times when an engine is subjected to greater loads and/or ambient temperatures during actual use than it was when the timing test was done . . It is better to have a little less timing than what is optimal than it is to have a little more than what is optimal because a little more may cause the engine to hurl.

One issue is that the point at which an engine detonates is not necessarily the LPP for that particular engine, and in cases where it is not the LPP when an engine detonates, additional power can be gained by doing things to reduce detonation like running a colder plug than stock, however, this is typically only done when the static compression is more than around 10.5:1 . . A plug of the same heat range but which has a retracted tip can also be tried . . Also, installing a cold air induction unit on it [if it is a car etc] so the engine can get air that is the same temp as the outdoor ambient temp instead the air from under the hood, which can sometimes be around 180 degrees, will also reduce the potential for detonation plus it will increase power because the colder the inlet air temp, the denser the air will be and the denser the air is, the more oxygen it will contain.

Detonation, or the potential for detonation can also be reduced by improving cylinder cooling . . One way this can done on air cooled engines is by adding additional size to the cylinder fins . . These fins are designed to keep the cylinder from overheating even with the maximum factory overbore, however they can be insufficient when big bore kits and/or stroker kits are added and/or when compression is increased etc.

The potential for detonation can also be reduced in a 2 stroke by improving the quench band in a cylinder head that has a poorly shaped one, and it can be reduced in a naturally aspirated 4 stroke that has quench pads in the combustion chamber by reducing the distance from the top of the piston to the cylinder head to around .034 to .043 inches with closer to .034 being better . . Detonation/preignition potential can also obviously be reduced with race fuels and part of the reason these fuels reduce it is because they actually burn cooler than pump gasoline. ?

To get the most power at all rpms, variable ignition timing must be used . . Some engines that operate within a very narrow rpm range like professional drag cars and weed eaters and lawn mowers etc don't have a variable timing system because that type is not "required" for those particular apps, however, engines used in transportation vehicles use a much wider rpm range, benefit greatly from having a variable timing system.

Inaccurate timing can cost up to around 10% of an engines potential hp and tq, and I have seen less than optimal power from inaccurate timing literally hundreds of times, however, the driver often doesn't know the engines timing is not optimized because it sill runs "ok" . . Incorrect timing will also reduce mileage and can increase the engines cooling requirements and actually cause it overheat if the cooling system is marginal.

Setting the timing to the mfg's recommended setting does not always mean that this will be the best setting for power and mileage, even if the engine is stock . . Mid 1960's thru around 1984 automotive engines which were non computer controlled, almost always had less total timing and/or a timing curve than was optimum . . This was intentionally done by the mfg's to meet emissions requirements . . Because of this, modifying the timing on many of these stock engines will increase mileage and power and will also reduce the engines cooling requirements.

Setting the timing to the mfg's recommended setting if an engine has been modified is not always the best setting either, and a modified engine will often benefit from a timing setting that is different than the stock one, which is another reason it is important to do timing tests on any engine to see what setting will produce the most power if that is ones goal.

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