Pipe Design !!Pictures!! on page 4! Nasty fast.

[RubberSalt]

Well I'm gonna get started on my pipe soon. I haven't check my clearances yet on how big it can be. But from what i can tell so far, the pipe isn't going to be an all out race pipe by any means. It's going to be a mid RPM range that should pull from I'm estimating at least 5k and top out at 8k RPM.

This works out well for me, as i designed my porting around mid to top end. After running the bike out at the dunes, I took note on how the engine ran. Ran better than expected but the RPM range was right where i wanted it. Power kicked in at the right time and everything. Now i just need a pipe to fully utilize my design.

Problem I have is the pipe it self, if i want it to match my porting perfectly, it will need to be an out of frame style or I'll need to cut my fenders. Neither which i want.

The pipe will hold my engine back a little, but it will be WAY better than stock.

This little software will help design my cones, so they match up evenly. http://www.pulserate.com/ It's free
Now for the interesting part, here is where i got these numbers, it compensates for a 90degree bend in the pipe already.

http://img811.imageshack.us/img811/1912/pipedesign1.png (http://imageshack.us/photo/my-images/811/pipedesign1.png/)
http://img405.imageshack.us/img405/1313/portsetup1.png

I'm not sure of my compression just yet, but I will be checking that in a day or so.

[BGP]

Fun stuff. Just out of curiosity, with all that blow down time area you're now running with the addition of those auxiliary exhaust ports, widening and raising of the main exhaust port and the fact that you're shooting for a peak of 8000 rpm, did you leave your transfers "that low" on purpose? Are you thinking that by the time your transfers open, cylinder pressures will be such that you'll actually "draw" from the base through your transfers? Or did you not shop at CC specialty tools to get a proper right angle handpiece? ( poking fun at you here...) Also, what makes you think that your engine's state of tune will let you use a mean effective pressure of 9.41? Lastly, nowhere in your values do I see and anticipated gas temperature... does the software loosely extrapolate values based on fuel type and BMEP?! At this point, if you're doing all this work, I'm sure you've read a bunch of books; who are you mostly coming back to? Jennings, Graham Bell or Blair?
Btw, go back and read Jenning's thoughts on the 2 stage vs. 3 stage diffusers, their lengths and effects on power distribution in the rpm range and see if you still want to build that pipe. Can't wait to see what you come up with.

[RubberSalt]

I've done most of my reading with bell.
I did leave the transfers that low on purpose, didn't feel like messing with them. I did raise them on my other cylinder, just time consuming. I've gone through, some more thinking and I'm going to go for a 7500RPM peak. The manual for the YT175 shows 8200RPM when looking at ignition timing. The ports i set up pull very hard from the mid range up to the top with a stock pipe. I feel a pipe designed to take better advantage of that would be peaking around 7-8k. But I'd like my pipe to be inside the frame. Being it's in the frame, I have decided to go with a broad range of power with a skinnier pipe.

The temperatures is something that has got me on this program. It doesn't factor in compression at all, but it does suggest an exhaust wrap with these pipes. I'm going to have to go with the loosely extrapolated values based on fuel type. It gives 3 settings for fuel. Now being this engine is air cooled, I'm probably going to use a slightly larger stinger than the program suggest. Might hurt power some, but it'll keep the heat down. I've got a silencer off a blaster, so the stinger is going to fit that thing.

Now I have a few other programs to help with the pipe design, 1 gives what it calls "average gas temp" at 600*c. This give sound a speed of 592 m/s. This is with 8000RPM, same port timing/size, and power development at roughly 29hp.

For the most part, just about ANYTHING is better than stock lol

[BGP]

Here's your pipe Sunshine:

http://i108.photobucket.com/albums/n4/bgp996/rubbersaltpipe1-1.jpg

You know, if you don't feel like messing around building a pipe, an old RD350 pipe like a DG or an FPP might be a good start for you if you can find one (or a set) rather than something off a YZ or CR125. Those temps seem high for what your pipe will see riding around; so the pipe would be a little shorter for the rpm your aiming at with speed being lower. How many gears on your 175? How close of a ratio is the gearbox? Look at the pic and visualize a shorter first diffuser with a slightly longer belly... To me that pipe looks like it'll want to be between two gears more often that you like... I like the "reversion" cone however. Btw, how do the values compare to the stock unit?

[RubberSalt]

I've got a YZ125 pipe, with some modifications, it could work. You know, extending it in a few places. But the power wont hit like I'd want it to, im sure of it. But the header pipe is the same diameter as my exhaust flange. I might rig that up to see how it does, but I'd like a custom pipe. If everything worked out well, I could share with the world and tell them how to build it.

The 175 has 5 gears and they are pretty tall gears too. When i shift from 2nd to 3rd when wide open at the top of the powerband, the pipe falls short of 3rd gear, it doesn't quite get on it for a little bit, atleast 5 seconds. Most of my riding is dones in 3rd gear, 4th was hard to get too - but I'm sure i may be a little lean still(gotta check).
The stock pipe is.. not that big i want to say it was 80mm at the fatest part. That doesnt mean the baffles either.. The header pipe has some factory placed dents in it to keep it close to the frame. It's really not a good design and most everything can be better. I found a picture of it, but it was in the toilet, so i found 1 off google for ya. http://img.auctiva.com/imgdata/5/9/8/0/3/8/webimg/431604087_tp.jpg

About what temps should i shoot for? This area is a part that eludes me as it's an odd area. Air cooled riden very hard. Cooler is better, but cooler has to hurt the power.

I could go as far as just putting a cone with a belly on the back of diffuser, near the drain plug lol. Pipes with drain plugs just yell "HORRIBLE" lol


Thanks for all the help on this btw, i am taking it all into consideration. Do you have a program you use for this? Or just experience/Mathmatical formulas?

[BGP]

YUK! That whole thing belongs in the toilet! The problem with temps is how fast it falls off when you're not "on it" and where/when you ride. A pipe that's been cycled in a dyno room might show tremendous values and fall flat on it's face out on an icy cold lake the first time you grab a handfull of throttle. Like I stated, however, it's not such a bad thing for someone like you in a sense that the thing will be too long and help you come out of the proverbial "hole". If it were a clutched snowmobile, you'd get off and urinate all over it out of frustration because it wouldn't peel the skin off pudding! So, use a lower BMEP in your case... say 8ish. Second, have you ever touched your pipe's belly right after stopping on the trail? Let me tell you that my FMF belly isn't as hot as a pan of fries comming out of the oven at 425 deg F. They cool fast! I'm just saying that most of the time that you get on it, the pipe won't be there until 3rd gear or so. With me so far? That doesn't, however, mean that you should use a 375 degree value! It's just not a drag sled or a race bike.

Having said that, i'd calculate dimensions for say, a range of lower temps in your case. Keep in mind that the 600C you're using is 1112 F; a few inches down the port with a stoichiometric ratio, yes, but not for a mean temp. Let me go back to some notes and suggest something for you later. You'll also want to play with the stage factor value. Those will give you a sense of how much difference is involved between each level of tune ( read BMEP and exh gas temp in the pipe, hence, sound velocity ). In most cases, you'll find that you can get as much or more variance in fabrication tolerance and execution than you would from temps. Don't forget, as you know, you can save yourself by tuning the stinger diameter and/or gradually wrapping the pipe if it signs off too early. In other words, build it "long" and regulate the heat rejection to tune it... as long as you start with a decent design.

Great, you got my mind going again! Better sharpen some pencils and dust off my notes...


Funny story, when I first started seeing your posts on porting and "third porting" It took everything I had in me not get on here and blast you like the "idiot" I thought you were, dilling ports with a cordless holding the cylinder by hand and porting with a dremel !!! Ugh! Have some pride dude! But then I remembered doing my first "porting job" at 13 using my mom's nail files and father's saw sharpeners on an MX175 just because it all looked "wrong" to me. Loe, the thing ran way better when I was done! I guess we all need to start somewhere and on a budget... One thing is for sure, someday you'll be shopping at CC Specialty tools too. (hint) ;)

[Billy Golightly]

This thread is starting to seriously interest me... keep the discussion going guys. i dont have much to add for the calculation aspect of pipes...but ive tried to build and section one, and im a pretty good tig welder and fab guy, and the pipe kicked my ass. so bad infact i threw it away without ever even taking pictures of it.

[atc007]

Easy to do ! Cleaning up ports is easy,this stuff here?? The less I know the better!! There are some places I just draw the line!! I knew you'd be all over this Billy! Good stuff! BGP,if you were American,I could prolly guess who you are! But,I don't know anyone North of the border cept my Nephew and his in laws.I spent a few afternoons at Silver Speedway,and other tracks,Repairing cones ,and taking out dents,,sometimes the guys SWORE they ended up w more power and or different powerbands. I have nothing to offer but to watch! And oh yeah,,rubber,,don't let the naysayers stand in your way,,you have some good ideas,but you already know that! But,,wear your helmet!

[beets442]

1 street(denco)expansion chamber:cool:, which is a great mid range pipe from a Kaw triple 500 would be good for a 167cc cylinder and a 28mm carb. Is that close enough to work with? I know making your own has a better cool factor and thought it was close to what your looking for. Those early 70's Yamaha enduro 175's were one of the best mid range kickers too.

[NINJA]

Listen to BGP.

[RubberSalt]

I took more measurements off my cylinder and the frame. I reentered the data with a lower BMEP. Now the pipe, for the most part, is tucked away from a lot of air flow, but I think i will wrap it with an exhaust wrap. Keep the heat inside the pipe and off the engine. The pipe does come within 1 inch of the cylinder head. Yamaha designed the head with a few fins cut short to fit the pipe above it. Thats half the reason i will be welding fin extensions to the engine.

http://img848.imageshack.us/img848/7821/pipedesign6.png (http://imageshack.us/photo/my-images/848/pipedesign6.png/)

http://img811.imageshack.us/img811/3052/pipedesign6targethp.png (http://imageshack.us/photo/my-images/811/pipedesign6targethp.png/)

Going for the 8000RPM peak, according to the program, this is more of a motorcycle pipe with a wide power band. As much as I'd like to have the higher hp, my gears are tall, and the wider power band would probably suit the bike better. The other pipe had the "track bar value" on the 2nd picture, set to 3.

I have noticed this program is giving a longer total tuned length with higher "Target Power Developed", all other variables the same.

[RubberSalt]

Now I've started writing a program, who knows if I'll finish it. It consist of taking the 'cones' and dividing them up. As an example. The pipe shown only gives 7 segments. These 7 segments cant me welded together to fit the bike, have to break them up into more segments.
Segment F1 is 284.8mm long, with a small end diameter of 40mm and a wider end at 52. That wont fit my frame without a nice bend. If i divide that into 8 chunks, it will flow so much smoother with a nice gentle curve. Each segment would be 35.6mm long, only thing that needs calculated would be the diameter of each end of the cones. And this software would do the rest http://www.pulserate.com/.

Now if you guys have a program to do this, GIMMIE' IT. Otherwise i will continue to create 1. I can do the math no problem on paper, but i feel everyone would benefit from some software.

[Billy Golightly]

I have the paid pulserate software and it works very well :)

[RubberSalt]

Does it allow for you to divide the cones up? If so, i might buy it.

[BGP]

EDIT: Cut out most of this... repetition and useless info.


Back to Salt's issue.
Speed of sound Ao=√[g*R*(TC+273)], where g=1.4, R for exh gases is 290.6 (287.1 for straight air) and TC is mean exh temp in degC. Jennings says 1670~1700ft/sec. is a good value to start with. Fine, what makes him think so? Well, in1973, he took some “good” pipes and reverse engineered them with Lt=Eo*Vs/N (Lt is tuned length, Eo is exh duration and N is rev) to find those values. So, what temp is 1670~1700 ft/sec (509m/s) anyway? Well, plugging it into the first eq, you find that the temp is a very weak 364C. Right, so be careful about plugging stuff into equations that say nothing of how they became.

For you Salt, I would start with around 475C and work out different scenarios up to ~575C. . Let's see what 500C gets you: 185*1837/8000 or 42.5” (1079mm) Sound familiar? BMEP is high on that input so you can say that the 500C is likely high too.

Also, Blair uses this equation for LT: LT=83.3*EP*Ao/rpm in mm... so for 500C; 83.3*185*560.7/8000=1080mm Ah, the magic 1080mm...

I'll post the rest of Blair's length and diameter ratios for you to compare between your program, Bell and anyone else...

Also, think it terms of pulses, BE the pipe, think of what is asked of you. Does your owner respect the fact that you have a power band to work with of the non-rubber kind? Are you drag racing? Hill climbing? Frozen lake racing or just pissin'about in trails? It all starts with heat assumptions.

[RubberSalt]

That explains why the higher the BMEP the longer the pipe. Sound waves travel faster, covering more distance in the same amount of time. So far, the program does appear to compensate for that, based on power.
At BMEP=9.41, it gave me a tuned length of 1079.9mm.
This bike will be riden mostly at dunes, shooting to the top, riding through trails down there. The lowest temps i have taken this bike out it was around 50degrees Fahrenheit.
Now i have another program that does that also. But it isn't accurate at all. At 18.3KW it shows temps at 350c, at 18.4kw, it shows temps at 500c. and the pipe doesn't change at all lol. "Expansion Chamber Design"

I've made a simple program based on Jennings's work. It calculates the speed of sound, his recommendations of Port timing VS RPM, I'm adding his tuned length formula to it also.


It will see temperatures mostly from 60-100degrees outside, not much cold.

[BGP]

Now you're seeing it. Be careful with Jenning's, his book is fantastic but some values that might have worked in the sixties are a little off these days. For example, that 1670~1700 ft/sec sound velocity.Time area stuff use for sure. The tuned length formulae are all based on the same principal; how long is the port open for and when is the wave due back for the heat that's in the pipe.

Have a look at what a 2 stage Blair pipe looks like for your zoot. The top pipe is one that I set for 7500 rpm peak and tweaked it to help broaden power delivery. That 2 stage looks sweet but it looks like it belongs on a racer or post '90 bike.

http://i108.photobucket.com/albums/n4/bgp996/saltpipes2.jpg

[RubberSalt]

That 2 stage is nuts, The stinger is... gone?

This program also calculates 2 stage pipes. I did take note though, the reflector cone and the stringer are always the same length with this program. From some formulas i found a while back, they were not the same length after calculating them. If Blair was more accurate in his work, then i need to locate his formulas.

This 2 stroke calculate appears to use Jennings(guessing). Or their own formulas. The stinger and the reflector cone are the same length, it doesn't matter if it's for a 2 stage or a 3 stage. Doesn't matter if its gas or methanol.

http://www.mh-aerotools.de/airfoils/javapipe_en.htm This program only does the single stage, but it uses a different formula for calculating tuned length. Doesn't state anything about the BMEP and estimates your engine displacement. Exhaust port area is 1250(roughly).

[RubberSalt]

http://members.cox.net/steve.stevens.bbq/modelengines/expcham.htm
This must be where my 2nd program came from, everything looks the same. I now understand why there is such big differences in the exhaust gas temps with only .1kw power difference. The main issue I'm seeing with the program is the "Horn Coefficient, kh" doesn't matter what number i put in it, it always reverts to the number 2.

I understand it more after finding this website.

[RubberSalt]

Heres the simple program I wrote in giving tuned lengths, exhaust temps, and target RPM for port designs.

http://www.2shared.com/file/rAJ40p78/2_Stroke_Information.html

[RubberSalt]

http://img684.imageshack.us/img684/9454/pipedesign7.png (http://imageshack.us/photo/my-images/684/pipedesign7.png/)

My exhaust port is bigger than the 40mm in the other designs. The flange is 40mm wide.

After doing TONS of reading, i understand much more than I did earlier today, at least with Blair's work. The design of this exhaust is similar to his design.

The 8.63BMEP falls right where you suggested. According to Blair's formulas, the exhaust temp is 450c. Got this from calculating tuned length based on Blairs sound wave formula. The tuned length is without the stinger in this program. The tuned length is a lot closer to where I need it for this bike also. My port timing should hold strong at 9000RPM. But most of the power will be produced before then. So 8500RPM should be fine for peak performance.

Another program I have worries about ring flutter and carb size. It states, for my 172.1cc engine, at 8500RPM i need a 28.3mm carb. It also states that a yz125 needs a 32.5mm carb at 11,500 RPM... SOO I think I'm going to stick with my blaster carb until i get me a nice flat slide 30-32mm.

For ring flutter, as long as my rings are less than 1.2mm thick, then I should be OK. It claims possible flutter can occur at 9000RPM with 1.2mm or thicker rings. Time to go measure.

I may go from this 3 stage diffuser to a 5 or 6 stage. After all, I'm going to be making a trillion tiny cones, might as well make it flow the best i can, right? Anyone have suggestions how to roll the metal into cones? My hands should be strong enough right? It is thin thin metal..

[BGP]

Wow! Slow down and step away from the computer! Go have fun and let your subconscious brain absorb that crap... you're taking in too much in one shot.

About the Steve Stevens page; that is all Blair. However, watch out for the following: 1) That EXD formula doesn't really apply anymore with the fancy port shapes we have these days. Use graph paper and figure it out yourself. 2) The gas constant (R=287) he shows is for air, like I said earlier, exhaust gas is 290.6... not a big deal but still different. 3) The K constants for diameter equations are getting old... think for yourself on those, that is what gets sorted out on the dyno. Besides, look at the OOF FTZ pipes; what K are they using? 5~6 on the mid section?

I'm at work so haven't really read your other posts but caught these: 1) my Blair pipe stinger is partly inside the pipe, reduces noise and o/all length without affecting tuned length. 2)Kh is another one of Blairs whacky ideas; kind of like that formula for finding D2! Love it! 3) Is your port diameter 35.57 or 45.12mm? 4) Cut your cone layouts yourself and take them to a sheet metal shop. Ask'em to roll'em up for you... sometimes they get such a good laugh off your back that they do it for free. Otherwise you really need a slip roller for cones to be nice. Some guys will throw an educated guess at how many cuts they would perform on the pipe and add that many blade thicknesses to LT. Fab the straight pipe then cut, rotate and tack weld the pipe around the machine and finish it on the bench. Another tip, if you ever make one out of stainless steel, that stuff shrinks alot with heat; build additional length into you design to end up with the right LT. Otherwise you end up with a pipe that runs 500 rpm higher than anticipated.

BTW, thanks for all the cool sites and info!

I'll read the rest later and comment if need be.

[BGP]

Hehe!, just read another bit: "5 or 6 stage" pipe... Might as well make a hydro formed pipe. That's probably the best solution for you. Once formed you make a few staregic cuts, rotate stuff and weld it back up.

[BGP]

Go watch this:
http://www.jl-mxshop.com/factory-tour-4-w.asp

Man am I glad we have a lazer table and a waterjet to cut the shapes! And a pinch roller to roll stuff up.

[RubberSalt]

That program does allow for different exhaust shapes, and it does give different results for me. Triple port and bridge exhaust are missing though(shot them and email to suggest it). My exhaust port can be difficult to measure, the main port is 43mm wide and 28.61mm tall. My triple port are about 10mm tall and 16mm wide. They are all oval shape... soooo I know how to do this, my program here calculates ovals! :)

I've did some math based on Blair's and Jennings ideas for pipes. Jennings is different. Blair is somewhat similar to the program, but it's not the same, close though.

Main exhaust=36.65mm diameter Single triple= 13.28mm diameter
Total surface area of ports (3.14* (36.65/2)^2) + ((3.14*(13.28/2)^2)x2)=1329mm^2=3.14*radius^2
That gives me a port "Radius" of 20.57mm. If i shoot for double that in the program, the pipe should be close. Time to re-input data.

That is awesome. I actually had similar ideas with hammering the cones on top of another cone! And grinding the edges flat. Only thing they didn't do in the video(they probably good enough) that I would have been doing, is checking the welds inside as I welded it together, and anything that went through to the inside would be ground smooth.

I was going to avoid stainless, harder to work with and I read it's brittle once ran. This pipe is mostly going to be tucked away safely. I've got some, but it's a little thick to me. I have a feeling we are getting close on a making a pipe.

I'm thinking either 18-20gugage steel.

[BGP]

That is awesome. I actually had similar ideas with hammering the cones on top of another cone! And grinding the edges flat. Only thing they didn't do in the video(they probably good enough) that I would have been doing, is checking the welds inside as I welded it together, and anything that went through to the inside would be ground smooth.

I'm thinking either 18-20gugage steel.


There was a dude in the background pounding the welds flush on downward sloped "anvil"... before you saw the cone touch up stage.

You'll find 18Ga to be thick... 20~22 is nice but also easier to burn through.

I also sent you a PM... Merry Christmas!

[RubberSalt]

No luck in seeing a Merry Christmas, is it a scavenger hunt Merry Christmas ?:)


Another picture of a theoretical pipe! More accurate data this time around

http://img824.imageshack.us/img824/5517/pipedesign8.png (http://imageshack.us/photo/my-images/824/pipedesign8.png/)

[BGP]

Really? No working link?

How'bout this: http://homepage.mac.com/rg500delta/deltaphasetwo/Frames/pipe_design.html Haven't read anything yet but just glancing over it seemed promising!

(Fapfapfapfap)

[RubberSalt]

I've read through all that a while back, it's a good read for information and trial and error. It's 1 of the things where I got a lot of my information, based on which angles to use and where. At least it was 1 of the original places for me. It was the point were i took his 31-35 degrees of blow down and started doing some math for my cylinder. 185-118/2=33.5

My IT cylinder came in, I'm starting to wounder if it's from 77-78 like the ebay said... I'm going to go port match it to my spare case, make sure it is going to seal up.

Has way bigger intake compared to the YT - might fit blaster reeds from the get go.. might fit cr125 reeds with some work. If i do port this cylinder, I'm going to weld up spots for the triple ports, weld up for the boyesen ports, widen transfers more in the cylinder.If it needs bored over(been honed but could be egged!), i might try something different. I'm going to test this with my spare cylinder first, see if i can bridge the exhaust port with some 1/2" iron and start porting that. If that works.. WOOOHOOO lol

I know the new YZ cylinders don't have triple ports, they have a bridge exhaust and the ports are just weird shaped. Mine would be 2 ports that are HUGE. I'll leave this for a porting thread... Thats IF i decide to port this cylinder(we know i will lol).

[BGP]

For your pipe making... maybe you've seen this?

http://vanguardcycles.wordpress.com/2010/10/01/how-the-vanguard-v1s-are-made/

[RubberSalt]

Wow, that really helps me figure out how to get everything line up well. I feel like all my ideas are being refined and will end up with better results.

He came accross the same issue i was for seeing, rolling a long peice of steel into a cone. This is where i was going to divide it up into sections, possibly make slits in the template to roll parts of it individualy.

I'm going to shoot him an email, see if he can make just cones and ship them. You know, take the work out lol. If he wants more than i want to pay though.. looks like im still rolling them. One of these days I'm going to invest in a slip roller, end up with pipes for everything. You'll see me weed wackin everything with a moster pipe on the dang thing. See mo peds doing twice the orginal speed. See me in a hospital for wrecking on a Go-ped(ok i got 1 with a pipe alread lol), it almost put me in a hospital lol.

[RubberSalt]

I've out here now cuttin and testing and cutting and testing... So far Not so good news. No way in hell i can fit that pipe design into that bike, It's to far to soon. Looks like I'm either going to have to go for a lower RPM or higher BMEP. I should just make an out of frame pipe.

Diving the problem area up into smaller segments and seeing if i can get around the issues. Stage 3 is the problem area. If i was at home, i would just recalculate a pipe, but I'm not:-\

I'm using paper models btw, If my paper can fit the bike, then my metal should be able too.

[RubberSalt]

WOOO I got my paper pipe to fit - I managed to get the correct specs too :)

PAIN IN THE ASS lol

I recoreded every angle of every cone. The reflecting cone needs a differnt angle, almost hitting the tire. From the end of the reflector to the grab bar.. I have maybe 6 inches. This is without a stinger.

Looks like I'm going to try a stinger that is partial internal and have a silencer that sticks out next to my grab bar.

[WIkid500]

The partial stinger is a cool concept, quiets the pipe down and saves over all length. Good luck with the pipe rolling, post pic's when you get done. I hydro formed the pipes I made back in the day. SO far I have a gas blender with a tuned pipe, and a Yamaha QT-60 with a hydro formed pipe. Cool stuff.

Here's my friend dumping the mix into the blender.

http://img101.imageshack.us/img101/6250/050601132900.th.jpg (http://imageshack.us/photo/my-images/101/050601132900.jpg/)

[RubberSalt]

Only thing i have access to that could come close to hydro forming is a pressure washer that does 1400PSI. I have a spare hose i can modify and put a check valve in it. I haven't looked much into hydro forming though. Care to elaborate?

[WIkid500]

Only thing i have access to that could come close to hydro forming is a pressure washer that does 1400PSI. I have a spare hose i can modify and put a check valve in it. I haven't looked much into hydro forming though. Care to elaborate?


That's what I used. I gas welded my pipes together in flats then welded pipe fittings on each end. I used the same thread fitting that is on the end of the pressure washer when you take the quick attach nozzel off. To keep things safe I elevated the pipe with one end fitting off so it would fill with water to remove the air. When there is no air in the pipe you are inflating there is no danger of it bursting and causing harm because water doesn't compress like air. Even to inflate the little pipe the pressure washer was more than sufficient.

The only advise I have for doing this is add some extra material for welding on the edges, when you gas weld the sheet metal you don't need much filler if you clamp everything tight.

[BGP]

Here: http://www.two-stroke-addicts.freeserve.co.uk/mick/hydropipe.htm

and here: http://www.3wheelerworld.com/showthread.php?95083-How-to-build-an-expansion-chamber

[WIkid500]

Here: http://www.two-stroke-addicts.freeserve.co.uk/mick/hydropipe.htm

and here: http://www.3wheelerworld.com/showthread.php?95083-How-to-build-an-expansion-chamber


Good links BGP. That's exactly how I made my pipes.

[RubberSalt]

Doesn't look to bad, I'd have to make it in 2-3 segments I'm guessing. This bike has a nice weird curve right after you pass the engine.

I took my YZ125 pipe today, measured it. Total length was somewhere in the 810mm range. The stinger was 22.3mm wide...

Well that jogged my memory a little bit. Page 1 of this thread, I ran some numbers, real close to my actual data. The tuned length was 1035mm with a 22.2mm stinger. Being i had to chop the header pipe on the YZ pipe.. I decided to see if it would fit.

The YZ exhaust fitting, thing that goes over the flange, needs opened up about 1mm. I cut and shaped the header a little bit, made it rounder(dented up, why i own it lol). Reshaped it a little, got it to fit the bike much better. I took the rest of the pipe and added 2 sections of metal to lengthen it. So far I've added 140mm and have 1-2 segments left. Then i got to chop the reflector and change the angle. Right now, as it stands, the stinger hits the tire, and the tip of the reflector almost does also. Curse that weird bend!

For the 2 segments i added. I managed to roll them by hand until the edges met. I ARC welded(all i got over there) together. When the edges of th emetal meet up right, i don't blow through, otherwise it does. If it blows through.. damn, i fill the hole in then grind the weld out and make the inside smooth. Took them out back to an old VW Thing rear end, stuck them over some pipes coming out and hammered them round. I was impressed with how round they got for being so crudely done. They matched up perfectly. I feel alot more confident at making this pipe. The 18 gauge really wasn't that difficult to bend, but i man handle stuff a lot lol.

It'll be interesting to see what a YZ125 pipe that has been beat to hell converted over to fit a YT175. The fattest part of the YZ pipe was 113mm. Metal is about 1mm thick. When i was fixing the header pipe, some old carbon fell out of it, damn near 5mm thick!! probably stuck in all the dents lol.

When I do the tuned pipe, Should i use oxy/act or mig+argon... or that arc welder lol. I don't care if the outside is ugly, as long as the inside is pretty:)

[RubberSalt]

Well, after reentering data, and skewing the numbers a hair. I got my 'new' pipe . Instead of the 1327sq mm of exhaust port., I'm saying i have 1200. That gives me %10 less surface area. I also got a longer tuned length on it by getting a higher bmep, 9.10. Temps still come out to 480, which doesn't sound to bad. Now for cheating, i need to have a wider stinger still.

Program says i need 21.9mm stinger with the less exhaust port. I say it needs a 22.9mm. I reentered data for the smaller exhaust and for where it should be. for the BMEP to be at 9.1, i need a stinger of 22.9mm

How far in does the stinger need to go? I've never looked into internal stingers.

[BGP]

You're starting to scare me again with talk of building pipes via stick welder (SMAW). TIG (GTAW) is my preference but oxy acet is the same basic principle; it's a heat source.

For the stinger, call around and ask for some " 1x.049 " A519 or A513 tubing... that's a little thicker than 1mm wall and has a 22.91mm ID. About the stinger, I once had a set of Microns and the stingers were in by around 6~7" ( plus the silencers ).

[RubberSalt]

I know, I just couldn't believe i was about to get it to work with a stick welder lol. But I'm pretty sure I'll end up using a mig with an argon bottle, maybe oxy acet(gonna have to brush up on it) been 6 years since I've welded with gas.

Yeah, i was gonna just buy some tubing for the stinger. Lots of air craft places around here in Wichita KS

[RubberSalt]

Oh yeah, i forgot to mention. I went ahead and mapped my ports, calculated actual area size - use arc lengths and what not, atleast as acuratly as i could, using calipers on printer paper... lol. Anyways, my total area came out to be roughly 1200^2 mm.. I wasn't to far off by estimating a memory.. right ?:-p lol

I'm glade i checked. I was going to use 1327.966 for my exhaust port area. That pretty big >.< I was only 10 percent off lol. This actualy makes me happy. Means i can redo the pipe design AGAIN!! and it should be skinnier. I need to shoot for 39.098 diameter with that program.

[BGP]

Here's a video I was going point you to with regards to cone rolling, starts off well but ends up being kind of rough looking. Entertaining if nothing else.
http://www.youtube.com/user/GPapesh?feature=mhum#p/a/u/0/xw1Y0IZz15Q

BTW, got pics of any "paper doll" yet?

[RubberSalt]

Here is the latest and great and hopefully potential finaly design.
http://img217.imageshack.us/img217/8863/pipedesign9.png (http://imageshack.us/photo/my-images/217/pipedesign9.png/)

Comes with the extra needed length on the header pipe. A hair bit more power at lower RPM. Tuned to run exhaust gases at 477 Celsius according to Blair's formula of tuned length.

This is the paper doll i made, modeled after the pipe on page 1 with the 39.9mm diameter. It was a VERY tight fit that bearly cleared everything. Wish the header pipe was a few cm longer.. Oh wait that 1 above is :-D

http://img831.imageshack.us/img831/6845/photo05120232.jpg (http://imageshack.us/photo/my-images/831/photo05120232.jpg/)

That is the stock pipe next to it. The first 8 inches of the stock pipe are nice - then thats it lol. I don't have pictures of the YZ pipe yet, I'll try to grab some later.

[BGP]

If you can't find tubing, you can try this place. U-Bends are handy as well.
http://www.aaenperformance.com/snow_exhaust.asp

[Bretmd94]

:wondering really interesting stuff in this thread. I am smart enough to know whats going on, but adhd enough that it makes me want to beat my head on the desk.

Both of you have more patience than I (and a lot more brain power). I am interested to see where this goes.

[RubberSalt]

I like, but i have a feeling everything i need is going to be at "The Yard Store". A store here with crap tons of air craft scrap and metal and tubing. It's where i got the material for my reed spacer. air craft grade aluminum, $3 a LB lol. I got a 12mm thick chunk, enough for 5 spacers for $3.41 lol. I got the 18 gauge steel there for $10, 24inch by 48inch. If they don't have it, I'll be calling around.

I'll have to get pics of the inside where i added to the YZ pipe. It's sad seeing the outside, looks like some nasty welds that destroyed it. Then you look inside and are like "DAMN i swear that would have been it for this part". I don't know how it worked, but it did lol

[RubberSalt]

Here are some pictures of the YZ125 pipe, I didn't get a chance to work on it today, possibly tomorrow.

http://img828.imageshack.us/img828/5934/yz125pipeextension.jpg (http://imageshack.us/photo/my-images/828/yz125pipeextension.jpg/)

http://img706.imageshack.us/img706/4807/yz125pipeextensioninsid.jpg (http://imageshack.us/photo/my-images/706/yz125pipeextensioninsid.jpg/)

http://img543.imageshack.us/img543/7632/yz125headermod.jpg (http://imageshack.us/photo/my-images/543/yz125headermod.jpg/)

That's 18 gauge steel rolled with my hands and a hammer+a pipe. Arc welded with a Lincoln Electric 220v arc welder. Done at 40 amps with a 6011 Rod.

[BGP]

What is that.. a Noleen Pipe? It's worth a try, the belly is kind of fat for the crank volume on your YT but it should still be ok. Can't wait to see what you think of it. BTW, it does look like absolute garbage! ( Hahahaha! ) You sure you're not adding too much to it? Looks like it'll run in the 6500~7000 rpm range now. You added around 150mm to it right?

[RubberSalt]

I'm actually adding 225mm. It looks like some one cut a chunk out of the belly. That is awesome you recognized the pipe(i think). All i can see is the "leen", the "no" is missing lol. I wish i could work on it today, but i gotta help my brother setup his party. Tomorrow hopefully i can finish it. Fun part is cutting the reflector and changing the angle it's at.

[RubberSalt]

I finished fitting the pipe to the bike yesterday. GOD IT IS NASTY. But it is so beautiful all at once lol. I've taken my dads snap-on camera to it. It really doesn't look bad. There is 1 spot inside the fat part that his a little bubble of slag where i blew through. The rest is good, was grinding everything smooth as i went along.

Been chipping a lot of slag off, who woulda guessed? I do know it leaks, DOES NOT HOLD WATER. I'm going to take some oxy/act and smooth it all out/seal it up.

I haven't quite finished it up yet. Got 1 bracket and need to stick the stinger inside 3-4 inches. Currently, the stinger is about 1 inch from the back of m grab bar. I'm going to have a great day trying to silence this 1 lol.

Been trying to upload pics but the blue tooth is being a pain in the ass.

[RubberSalt]

I able to easily power slide the bike now, i wasn't able to easily before :) It's running lean as a mofo with this new pipe. Gonna have to take it out to the trails someday and tune it in. :)

[RubberSalt]

http://img23.imageshack.us/img23/9038/photo05161538.jpg (http://imageshack.us/photo/my-images/23/photo05161538.jpg/)

http://img684.imageshack.us/img684/6837/photo05161539.jpg (http://imageshack.us/photo/my-images/684/photo05161539.jpg/)

It made a HUUUGE difference, sounds WAY meaner now. Pulls much harder than the original pipe. Power comes on smoothly and evenly, doesn't just hit and trailprotrailprotrailprotrailpro when the power came, like the stock pipe.
I can't wait till i make the real thing, be better tuned, smoother welds, probably more segments for smoother contours. This was just a "see if i can do it"

Length is an issue. I took a shorty silencer, choped it in half(well measured first), i ended up bending the stinger a little more and turning the silencer sideways, the fenders are maybe.. 3mm off - gonna have to coat with heat resistance tape or something.

[Dirtcrasher]

You need a mig welder :D

[Bryan Raffa]

You need a mig welder :D

ya think.... lol hey you got a welding helmet? cuz it looks like you had your eyes closed on them welds...other than that ,, its cool..thoes bikes were horrably constricted..

[Modding_out]

I'm pretty good with a stick welder and if i may offer some help....

1. buy 6013 or 6011 rods, idk wth your using it's not right
2. use a smaller rod, looks like you used 1/8 inch rod, try 3/32 or 1/16...the 1/16 take some time getting used to, but once you got it your good.
3. increase your amperage, looks like you lowered it to much so you could get away with using 1/8 rod....always match the thickness with the rod and the voltage to the rod.
4. Do not weld over slagg!!!! chip it off any try again; grind it off high spots if applicable..... if you don't the ark will follow the old weld and make your problem worse.


I'm not trying to pick you apart, I'm trying to help you so you don't make the same mistake twice.:D

[RubberSalt]

You Hit the nail dead center on the head there, Modding out.
Used 6011 1/8th. at 40 amps, i lowered it all the way.

Alright, so i have 18 gauge steel, suggestions on rods? my welder only does AC current with the following amp settings: 40-225 amps.
I'm also gonna try a wider feed on this stuff, i bet I'll have better results.. lol

[Modding_out]

Well 6011 is a deep penetrating rod, it likes to "eat" in to the metal. it's also slightly harder to weld with fore some reason.
6013 would be my personal choice for some thing like this, 6013 puts down allot weld(good for filling saw cuts) strikes an easy ark and stays constant. it's not a deep penetrator though, it kinda melds into the part your welding, but at 18 gauge it's a non issue. 6013 get's picked on allot for being a "newb rod" but I think that's unjustified hate.
there is also 7018 rod with shares attributes of both 6013 and 6011, don't remembered all the details...google it.

As for thickness, try some 3/32 for starters if your not satisfied with the weld quality go with 1/16.

ac current is fine, make your leads are DCAP (or is that dcep? i forget...) and you'll be fine, your buzz box has plenty of juice .

[fabiodriven]

Between the welders, the op's R&D, and the pipe guru, I would have to say I am very impressed with the talent on this site.

Obviously the welds need some work, but you gotta start somewhere.

[atc007]

Nobody stands in Salts way! Good work,it only gets easier from here! A better welder or maybe even new cords? Would make life MUCH Easier for ya! Nice job though!

[beets442]

+1......7018 in 1/16th

[RubberSalt]

If i get a chance soon, I'm going to try out the 6013 and the 7018 rod. I have a feeling my next attempt will be much nicer. I'm going to spend more time on it, instead of rushing through the only free day i had at the time. Maybe spend a week getting it perfect. You know, take all the time in the world. Then toss my current pipe on my 125 and watch it be confused. "Do i go fast or do i go slow?"

[BGP]

...ac current is fine, make your leads are DCAP (or is that dcep? i forget...).

DCEP -> Direct Current Electrode Positive...

I may be wrong but with AC welding its constantly "alternating" between DCEP and DCEN, no?

BTW Salt, I like that shape... it looks right for what you've done inside. Now go find a chep 110 Mig on CL! Good work man!

[Billy Golightly]

This thread is making me anxious to re-try building a pipe for my 500 again. The biggest problem I had was keeping the sectioned pieces I cut on the bandsaw ROUND when I went to weld them back together. I always wound up with a side that had a big gap and it made welding it together a pain in the balls. I seen in one of the videos BGP posted that they had an aluminum billet cone that they forced the sections onto and then sort of hammered back into round shape. I'm going to have to try that and I have the perfect piece of junk thats been laying around here for 10 years that'll act as my cone to form a round.

Salt if you can't get a mig welder....lay the thing out and mark all the pieces how you want it turned with a sharpie (so I can re-align the marks) and send it to me...I'll tig it up for you.

[BGP]

...lay the thing out and mark all the pieces how you want it turned with a sharpie (so I can re-align the marks) and send it to me...I'll tig it up for you.

SNAP!! I was going to offer tigging it up for you Salt, but the border BS would be a pain. But this offer right there is GOLD.

[Sparkplugkid]

need a sound video!!!

[RubberSalt]

My dads got a neat little 110 mig welder I'd like to try. He doesn't let his tools leave his garage though.

If i do send it off to get tigged up. I could tack weld all the joints first. With a mig. I'm gonna have about a week to my self soon, so i may try to build the next pipe then. I'll defiantly be taking my time on this 1. The 1 there I spent about 10 hours on, kinda rushing through things.

I'll have to get a Sound/Riding video for you, Sparkplugkid. It needs tuned in pretty bad now, so.. I'll have to wait till i get some one to haul it out to the trails lol.


Edit: I NEED A TRUCK lol

[Modding_out]

Sounds like you've got allot of options open for you when it comes to welding:naughty:

Here are some pics of a weld I quickly threw down
It's 6013 1/16 rod, can't tell you the amps I was welding at, cause my welders so old the painted on dial has rusted away:rolleyes: , I just go buy feel and visual checks of what welds the best. But any way, I just posted these up cause of you go this route you'll know what weld quality to expect.(It was prolly running a smidge to hot in the pics)

Top http://www.3wheelerworld.com/attachment.php?attachmentid=124283&d=1305765976

Bottomhttp://www.3wheelerworld.com/attachment.php?attachmentid=124288&d=1305766022

http://www.3wheelerworld.com/attachment.php?attachmentid=124286&d=1305766011http://www.3wheelerworld.com/attachment.php?attachmentid=124285&d=1305765998http://www.3wheelerworld.com/attachment.php?attachmentid=124284&d=1305765986

[RubberSalt]

Nice, I know what rods I'm using lol.
Gonna have to buy some and practice before the next pipe. Although. With the next pipe. I'll probably be tack welding everything with the arc and finishing it off with the mig, doubt my dad wants me to use all his gas lol. But i wont lie, i could use some serious practicing lol.

I've got some 6011 1/16 rod but it blows through everything, I haven't tried them on the 18 gauge yet, but I'm going to test them. I bet i end up getting 6013 rods.

I'm going to be looking for some 20 guage steel, the 18 is heavy, almost as heavy as the stock pipe lol.

Thanks a ton for the pictures and help!

[Thorpe]

A nice metal fit, all tacked up, and let Billy tig it for you! A tig would be such a sweet, leak free weld... I dig the amount of R&D you have into this build! Never built a 2 stroke pipe, but lots of hot rod headers.... A tig will yield the prettiest results... http://www.heartthrobexhaust.com/ is where we would buy all of our mandrel bends... Even stepping to 16 gauge isn't a terrible idea. Its more difficult to work with, but will warp less under the heat of the weld (just an option to consider)

Billy-- bandsaw trashing your pipe shapes... try using an abrasive cutoff wheel instead...?

[RubberSalt]

Only thing i had to cut it with was a 4.5" cut of wheel. I'll be cutting a better way to cut it with my assortment of tools. Cutting isn't a problem, just didn't have the tool i needed.

The hardest part i had was getting the cones perfectly round. I didn't have many round things to hammer them on to make sure they were round perfectly. But they were pretty dang close.

[Thorpe]

We would usually spin a 4" wheel, .035" thick in a pneaumatic die grinder... (3m green corp) Was the easiest way to cut, without destroying too much in the process (fwiw)

[RubberSalt]

I got the jet kit a couple of hours ago, so i can finally start jetting that thing and see how it really comes to life. I tuned the bottom end better. The stock pipe, I'd say has a little more bottom end torque. But that was to be expected. Most pipes don't really give more power, but moves it from 1 rpm range to another. I moved everything of mine to the mid and top end. And I'm lean on the mid and top end.. lol

Come Sunday, I'll have it tuned in a lot better. Girl is turning 21 Friday night, so I'll need Saturday to recover. I also got a vid of it running nice and lean. I'll have to get it from my buddy, that could take ages...

[RubberSalt]

Oh yeah, If any of you want some pipes designed by this neat little program of mine, let me know.

I'll need to know a few things though. Width of exhaust port. More or less, as close as you can get to the total surface area. Stroke, bore, exhaust port durations and the transfer duration. Desired RPM range and what type of pipe you'd want. High HP with narrow power band or Low HP with wide power band. I prefer a wide top end power band :-p

And what bike/engine it's for

[Bretmd94]

Very good job, I can't wait to see a finished product with proper welds.



Oh yeah, swap your tires around! lol Those pro-wedge's are meant to be run with the scoops backwards.

[RubberSalt]

I need to, now that i have more hp. Some reading I did claimed i could run them backwards, for lower hp machines. I need to test them the other way. Maybe when i start tuning I'll swap them. I was happy to get them pro wedge - $30 :-D

[RubberSalt]

Well, it's been to long for me, atleast 3 days! Thursday looks to be my next chance to tune it in. I can't wait to see what the bike does then! It makes me sad, i got this beautiful hideous pipe that i haven't got to really play with yet lol.

I'm strongly considering using my 34mm carb, i do have big reeds now.

[RubberSalt]

My pipe works. Hit 3rd gear where i normally top out 2nd. Then i lost it and hit the ground pretty damn hard with my knee.

I don't normally drink, but right now, i am. Pain is gone. I also have ice on my knee and my leg is being kept elevated and straight.

[zzmegad]

take care of those knees, ice is good, knee pads better, my knee just started bothering me again last month from an injury that happened over 10 years ago... And it's been fine this whole time, wth

[RubberSalt]

When it got on the pipe after tweaking the jetting some.. DAMMN it pulled like a bat out of hell on steroids!.

I've started taking vitamins, to help target what my body needs.
Vitamin A
Vitamin C + rosehips
Magnesium
Calcium - liquid gels
1 more i cant remember right now.

[Chazz of Blades]

I made a booboo about a year and a half ago, I layed a mini bike over in wet grass, going MAYBE 5-10 mph, cracked my right kneecap in between ground and metal tank. I can't ride in the backseat of a car anymore, and my knee still hurts like hell every now and then.

[RubberSalt]

I'm going to have to figure a home nasty fix remedy for it. Cut it open, JB weld the bone together, use my acetone jbweld mix.. lol. I've got 2 knees to practice on.. right? lol

I want to make a 2nd pipe, but a swing arm is more important.

[RubberSalt]

I've noticed a fn thing about my pipe. It pulls harder when cold. Sounds like i need a wider stinger or to extend the pipe a few mm.

[RubberSalt]

Looks like I'm going to be starting on another pipe soon. This 1 is for a Blaster. I'll keep this thread updated once I get started working on it. I know it's not for a 3 wheeler, but it's still building a pipe!

[Six Stroke]

Oh yeah, If any of you want some pipes designed by this neat little program of mine, let me know.

I'll need to know a few things though. Width of exhaust port. More or less, as close as you can get to the total surface area. Stroke, bore, exhaust port durations and the transfer duration. Desired RPM range and what type of pipe you'd want. High HP with narrow power band or Low HP with wide power band. I prefer a wide top end power band :-p


And what bike/engine it's for

I may have to take you up on that when my YZ Moto project is a little further along. Something better than a stocker 175 pipe would be righteous.

[RubberSalt]

Now that my knee is useable - im thinking about a new pipe... Out of frame design.
The 3 issues i came across with the YT - cramped in the frame, tuned length made the extra shorty exhaust meet the end of the grab bar, many bends, pipe is right above the engine - less cooling on engine

Out of frame = no cramped areas, no length issues... and less bends... and more air flow to engine & extended cooling fins = more comp i can have:)
Out of frame downfalls - if i roll bad, good bye pipe, pipe temps will be hard to maintain, have to design it far enough away, that its not in my way.



btw - i got a mig welder to use now lol