Atc 88 dyno results look!

[81Rmachine]

Hey guys just thought I'd share my dyno results with ya! I made a couple dyno runs a few weeks ago and finally found the time to post my results. What I've got is an '85 ATC 70. Everything I've put into it includes

88 cylinder kit
20mm Keihin carb
K&N filter
5 angle valve job 30 degree back cut valves and ported original honda head (Machining and porting done by me)
Beatrice Cycle race roller bearing style cam
Cobra Pipe
Parts Unlimited chain
Kenda scorpion tires

I've found Honda rated these at 3.5 horse and while I didn't get to dyno it stock I did dyno my '74 z50 which was about equivalent in power and that produced exactly 3.5 horsepower and 3 ft.lbs. at about 6500 RPM.
The ATC after all modifications did quite a bit better making 16 HP at 10,200 RPM and 8.5 ft.lbs. at 8,500 RPM and as you can see by the dyno chart the torque curve is pretty broad in fact it never fell off to my surprise! Like I said I can answer any questions I did all the work myself from machining to dyno runs.
137149137150137151137152

[alexandros]

looks interested, same power as the 150cc china-honda engines!!! any video of the atc to hear the engine?

[350xx]

Wait...if a 88 makes that much power why would i get a china engine! hahaha

[Trikeboss]

16 HP with an 88cc kit @ 10k+ RPM... WOW thats just unreal! A 140cc lifan I had made like 8 HP....

[PerryS]

Id never thought that you could get 16hp out of a 70 motor with that list of mods. What kind of fuel are you running in it? I was gonna build a 70 with a 155 pitster, but that makes ne want to keep it genuine honda.

[murfman]

Makes me wonder what you can get out of a 150cc or even 190cc motor. 20HP?

[big specht]

That sound alittle high out of a 88cc . Not sayin it is not possible. I've always wanted to dyno one of my 70's to see where there at, the problem with all mine is they are all push start differant flywheels. I have one that is all honda bored out to 90cc and a china one that is 160cc .

[bigworm626]

Unreal numbers.. but the dyno don't lie. thx for the input.

[55stone`]

thats crazy high i would totally keep my 70 all honda and do this if i knew it made this much power

[hummbusa]

thats crazy high i would totally keep my 70 all honda and do this if i knew it made this much power
+1 I can't imagine a 88cc running with even the 110-120cc let alone the 140cc+ monsters

[PerryS]

It must be running on alcohol or race gas to make that kind of power.

[MrPretty]

Wow! Thats just about as much power as a first gen 200x

[ezmoney1979]

Seems like it would have to spin to 20,000 rpms to make that kind of power.

[Husky250]

10,200 rpm???? WOW, that would scare the hell out of me! You definitely have some hair on that ass! I wouldn't have the guts to push it like that!

[bigworm626]

hats off 81R! big ups kid kash.

[Thorpe]

I need more info... And a 5 angle valve job!!!

[81Rmachine]

I run it on 91 octane pump gas. 11 to 1 compression. I did some pretty elaborate porting, flow testing, and chamber work to get that kind of power. It was done on a Mustang Dynomometer which are claimed to be the most accurate in the industry. I had thought about a lifan when I got it but I wanted to keep it honda and I had access to a machine shop and a flow bench so I had no excuse not to use the original honda head. The cylinder head is where its all at. The power an engine can produce is solely limited by how much air can get through the cylinder head. Cam events and everything else must fall into place as well, but you wont get anywhere without a good flowing head. Th.e valve job was also a huge improvement over stock going from about a .040 seat width (common on an automotive valve job) to a .020 seat width. Many three wheeler heads ive pulled apart have black seats which is a clear indication the valve wasn't seating due to too wide of a seat. The seat I went to may sound too small but it actually is better for heat transfer as it doesnt trap carbon that would insulate the valve. 70 percent of the valves heat is transfered through the seat and if it cant do that then you burn a valve. I actually put this engine together a year ago and i've ridden it pretty hard Its got to have 50 to 100 hours on it and it really hasnt lost power im impressed with the longevity not problems yet. Oh and I've beaten a 200s and an '85 and '86 200x in a drag race down gravel.

[81Rmachine]

The five angle valve job consists of your typical 3 angles (60, 45, and 30) and it also includes a 75 degree throat cut and a 15 degree cut above the 30 to blend into the chamber better. I've spoken over the phone with Joe Mondello and Darin Morgan who is a pro-stock engine builder and he says a 15 degree change between each angle is optimal for both dry flow and wet flow and offers better fuel shear and eliminates fuel seperation and dries up the chamber.

[350xx]

The five angle valve job consists of your typical 3 angles (60, 45, and 30) and it also includes a 75 degree throat cut and a 15 degree cut above the 30 to blend into the chamber better. I've spoken over the phone with Joe Mondello and Darin Morgan who is a pro-stock engine builder and he says a 15 degree change between each angle is optimal for both dry flow and wet flow and offers better fuel shear and eliminates fuel seperation and dries up the chamber.

Amazing.
What kind of money did you put into her?

[Thorpe]

Sounds like I probably can't afford to hire you to work my 70 head over... Mondello, didn't he pass recently? I bought a few Olds goodies from Mondello over the years... 81r, what do you do for work up in Bemidji?

[MisterFurious]

Judas H. Priest on a popsicle stick; are you running nitro?!

[WilliamJ]

That is quite an output. I have built a few race engines for cars and to get more than 120hp per litre out of a two-valve engine is very good indeed. To get 180hp per litre - well, I have only come across that on four-valve full race Cosworth engines hitting around 10 or 11,000 rpm. If you are running on alcohol then that would be the reason, but if it’s on gas then it is truly amazing. The Honda Blackbird got about 160hp at best, and that was 1100cc so equals 145hp per litre. F1 engines have reportedly got around 250 hp per litre but that is using an ultra short stroke and 19,000 rpm.

Five angle valve seats, well-ported head, 11 to 1 CR, cam events optimized, these are tried and tested so what have you found?
Bill

[81Rmachine]

Yes Mondello did pass last spring. I had the privilege to speak with him a couple months before he died. It was a real honor for me to speak to Dr. Olds as Im a die hard Olds guru myself. Im actually a second year tech student up here in Bemidji and just last week at the Performance Racing Industry tradeshow in Florida I met and spoke with Mary Mondello who is now in charge of hiring and Cody Smith an employee who also graduated from Bemidji about employment this spring. Hopefully all goes well and I get to work at Dr. Olds very own shop.
Oh and as far as price I paid 400 for the 70 and a 185 i put about 400 into it.

[81Rmachine]

Hey Bill I see your from England so Im sure your very familiar with David Vizard and sounds like you've got 4 valve experience. I just had to ask if you've heard of Vizards "Polyquad" design? I just went to his seminar this fall in Chaska, MN.

[WilliamJ]

Yes have read up on the poly quad idea but not tried using it. It makes very good sense as better mixing gives better / more complete combustion. It was posted on a site that he seems to have stopped contributing to - Go Fast News.

My first tuned engine was built a long time ago using his Mini book from the 70s. The engine was an ancient 850cc A series Mini and I put a head with bigger valves from an 1100cc A series on it, worked the valves and seats, ground the chambers and ports to his design, raised the CR to about 10.5 to 1, fitted a single 1.5 inch carb and removed the inlet heating. Everything else was standard.

Before the work it would just reach 70mph. After the work it would reach over 100 mph - it actually went off the end of the speedo dial which only showed 95mph. 0 to 60 was just under 10 seconds and it would easily beat a standard 1275 Cooper S. A fair estimate is 80 hp at the flywheel. The man is a genius but I can understand why he went to the US. No-one rewards genius in Britain.

I would really like to see pics of what you have done....you did take pics didn’t you?
Bill

[81Rmachine]

Not of the 70 no unfortunately but I am currently doing an '81 Honda XL500s engine. Its a four valve chamber and ill be doing Mr. Vizards polyquad design here this next semester. Id love to dyno the bike when im done as well but im going to school 6 hours from home so gas gets expensive in the old full time 4x4 pickup but none the less ill have pics of the project.

[KASEY]

ok.. i have built alot of 70 motors,, and lifans and pitsters,, and i highly doubt the hp readings are accurate,, sorry but i don't see getting 5 times the stock hp with a few simple mods,,,, you made the engine 16 cc bigger than stock and added a cam piston and porting,,, and got 5 times the hp,,,,,, sorry it might run great and all ... but thats just a little strech for me.....

[big specht]

Maybe doubling the hp to 6 or 8 not 16 hp . Bring it to TF and drag race it then we will see

[VintageHondaKid]

I'm not gonna say that this is totally false... However, I'm from the show me state, and I could definitely go for a video of this thing beating up on the bigger trikes like you said it did. Then I'd be a true believer lol

[jb2wheels]

Unreal numbers.. but the dyno don't lie. thx for the input.

Actually - they do lie. If you don't compare before and after on the same dyno, same day, same configuration, same this that and everything else, the numbers aren't valid. And I bet the dyno accuracy is not very good at low output ranges.

Too many variables, not enough controls.

I'm not knocking the engine - it's a strong runner no doubt - I'm knocking the validity of the test and data.

[MIK6]

I have a few bigbore 70s. I have a few stock, a built all honda 88cc w manual clutch (built by jensen), a 110cc auto clutch and a 125 lifian manual. the 88 will crush the 110 in a straight line w/ same tires and gearing. It runs rite w/ my stock 125 motor set up the same way. I think the 88 has alot more torque and is snappy compaired to the 125, the 125 just pulls more due to displacement. ill have them both at TF12, anyone is welcome to try them!!

MIK6 / Mike

[81Rmachine]

That's why I ran the ol' z50 and posted results of that as you can see it read an accurate 3.5 hp for the 50. Some of my buddies actually ran their drag cars on this dyno in a 1/4 mile run and went down to Brainerd the next weekend with similar weather and were only two tenths of a second off. My friend also ran his 68 Camaro with a 496 BBC Merlin block Merlin heads, Merlin intake, a full roller cam and he made 410 HP at the wheels and he runs 10s in the quarter. My point being this dyno reads on the conservative side and Mustang is definitely one of the most accurate. Again mods weren't just simple bolt ons like most guys do. I had to do quite a bit of porting on the head and ill admit its a very peaky engine it likes to rev, definitely not a grunter. Before I machined and ported the head I had the 88 kit installed as well as the pipe and I was very dissapointed. My little 50cc honda express would walk away from it. I dont blame you for being skeptical I would be too, but if I can go from getting beat by a scooter to walking away from my brothers 200x I think the lil 88 is doin pretty good.

[torque]

all skepticizim aside if you had a vid of that little 88 walking all over a a healthy 200x you would make a few more believers. i personally would love to see that

[81Rmachine]

One other thing to note is the z50 wouldn't rev much past 6,000. It simply didn't have the volumetric efficiency to do it. It sat at that point for probably ten seconds on the dyno and wouldn't rev any higher so thats where I ended the test. With just the 88 kit in the 70 it was the same way also it just didnt rev much higher than that. Now if I can increase an engines RPM almost 4,000 thats really gonna raise HP. Horsepower is simply Torque X RPM divided by 5252. So lets say I didnt increase torque on the minibike and it made 3.5 ft lbs but I got it to rev to 10,200. That is 3.5 x 10,200/ 5252=6.8 HP and that is by just revving it higher. Now the ATC made about 8.25 ft. lbs. at 10,200 so thats 8.25 x 10,200/ 5252= 16.02 HP. Actual engine output is measured in torque not horsepower. Horsepower is a rate. I increased torque about 4.5 ft lbs as it was almost exactly the same power as the 50 before, but I increased RPM 4,000 so thats where horsepower really shot up. Most guys just see numbers and dont understand where they come from. RPM is a huge factor in horsepower, why do you think Formula one is always trying to spin their engines faster. Sure their engines make good HP but they dont make much more torque than alot of street cars simply because their HP numbers come from RPM. F1 cars will never compete with Pro Stock torque numbers, a pro stock engine may make 2000 HP but they also have about 1300 ft lbs of torque and run much less RPM. Just my lesson on HP and torque I guess when you break it down and look at the whole picture its not that hard to believe.

[81Rmachine]

http://www.youtube.com/watch?v=wBFl75yZBQ0
No race footage yet but heres just a little bit of riding around the yard on it. Its still a very mild engine at low RPM but really comes to life as it revs. Stock gearing the GPS says 48 MPH.

[briano]

Nice helmet

[KASEY]

don't need a dyno to tell me that is no where near 16 hp!!!! just from the first 20 seconds of that video.... sorry it sounds good but i am sure your not even close ,,,,,,

[81Rmachine]

Well then lets see some of your own dyno results and some footage of just how fast your 70s are Id sure love to see it!!!

[JasonB]

Regardless of hp ratings on that thing, nice work. I like it, I would rock it :D

[KASEY]

well i don't do dyno's but i do know i little about 70's,,, i have built a few ,,, lets see if i can find a pict or two,,, oh by the way these are all my 70 's... and i have alot more,,,,,,, so hmmmm yep i do know 70's... and i still stand on my statement,,,

http://i1141.photobucket.com/albums/n592/KASEYII/oilcooler.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC01577.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC01606.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC00011-2.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC00002.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC00236.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09547.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09607.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09569.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09728.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09736.jpg

[KASEY]

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09754-1.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09920.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/ATC70-155A.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09944.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC09977.jpg

http://i1141.photobucket.com/albums/n592/KASEYII/DSC00092-2.jpg

[AirManCam]

That is quite an output. I have built a few race engines for cars and to get more than 120hp per litre out of a two-valve engine is very good indeed. To get 180hp per litre - well, I have only come across that on four-valve full race Cosworth engines hitting around 10 or 11,000 rpm. If you are running on alcohol then that would be the reason, but if it’s on gas then it is truly amazing. The Honda Blackbird got about 160hp at best, and that was 1100cc so equals 145hp per litre. F1 engines have reportedly got around 250 hp per litre but that is using an ultra short stroke and 19,000 rpm.

Five angle valve seats, well-ported head, 11 to 1 CR, cam events optimized, these are tried and tested so what have you found?
Bill
My personal car has 200HP per liter on pump gas. We've built multiple cars that are pushing 400HP per liter. Got to love four cylinders and big turbos!

[torque]

did not think i could be aroused by 70"s guess i was wrong very nice bikes kasey

[AirManCam]

I agree, those are nice Kasey!! I'm going to build one after I finish my 350x.

[CRAZY70MAN]

Kasey....lol..... man you build some great stuff. I never chimed in when I first read this thread but coming from a guy that has raced several atc 70's that were modded.....I second Kasey's comment after that video. My 150 atc 70....inner rotor, KX head makes no where near that horse and I can tell ya if you gps'ed 48 mph you have a long way to go from where my 150 will take me. Good luck.....nice 3 wheeeler by the way. Bring it to Trikefest and you will see how fast it is.lol...sounds good

[81Rmachine]

Nice collection! I really like 70s and the A+ frames. I still gotta ask what your basing your opinion on you say you know 70s and it looks like you've dealt with a few you've got a fine collection but if you don't know what one of em makes for power why do you doubt so much what mine makes. Like I said its a Mustang dyno and the load cell was just calibrated. I'd like to see what some of yours are puttin out! I'm sure you've got a good feel for power by racing em but if you don't know what yours are making then how do you know mines inaccurate maybe yours are over 20 horse obviously mine doesn't make near the torque bigger trikes do but little engines have the revs to get the horsepower up. I definitely need to go up a tooth on the front it'll do 48 like I said with stock gearing my only point ther is how high its revving I'd like to gear it up a bit and see what it'll do.

[CRAZY70MAN]

http://www.muckandfun.com/index.php?option=com_content&view=article&id=6&Itemid=7 Scroll down the the brand new 160cc race motor and read its "APPROXIMATE" 18 hp. rating. That motor is twice the displacement of yours with absolutely all the best stuff money can buy and it is still quite a bit shy of 20 hp? Not saying it is not reachable....but that is where I based my hp findings for my yx150....from the factory specs they gave me. It would cost me 2000.00 in upgrades to get 2 more hp's out of mine. Nice build...we are not trying to haggle ya.......that is just a number I have a hard time believing when compared to some of these big bore newer motors. Great stuff still.:beer

[AirManCam]

Nice collection! I really like 70s and the A+ frames. I still gotta ask what your basing your opinion on you say you know 70s and it looks like you've dealt with a few you've got a fine collection but if you don't know what one of em makes for power why do you doubt so much what mine makes. Like I said its a Mustang dyno and the load cell was just calibrated. I'd like to see what some of yours are puttin out! I'm sure you've got a good feel for power by racing em but if you don't know what yours are making then how do you know mines inaccurate maybe yours are over 20 horse obviously mine doesn't make near the torque bigger trikes do but little engines have the revs to get the horsepower up. I definitely need to go up a tooth on the front it'll do 48 like I said with stock gearing my only point ther is how high its revving I'd like to gear it up a bit and see what it'll do.
You can calibrate dyno's to say what ever they want though. What was the correction factor, if any?

[81Rmachine]

Good to see some other HP ratings. I just wanted to see something other than opinions Ive never seen what those big bores are making. Certainly if a 160cc monster is making 18 HP the dyno was off on mine cause mine wouldn't be close to a 160. I just wanted to see some other ratings thats all. Thats exactly what I wanted to see, thanks for posting CRAZY70MAN!!!

[CRAZY70MAN]

Good to see some other HP ratings. I just wanted to see something other than opinions Ive never seen what those big bores are making. Certainly if a 160cc monster is making 18 HP the dyno was off on mine cause mine wouldn't be close to a 160. I just wanted to see some other ratings thats all. Thats exactly what I wanted to see, thanks for posting CRAZY70MAN!!!

You are welcome. I don't beleive anyone here is trying to tell you "I told you so" but there are members on here that eat,sleep, breathe 70's and the mods for them such as Kasey and others. I always am willing to learn or try a new trick and or listen to someones ideas, thats the way we all learn. You have some interesting points and ideas.

[TatTooL23]

even though some people eat sleep drink 70's or think they do, or think they r god here which i personally think is more of the case, no one has posted dyno numbers. and no one has talked about the mods done in this case as in depth and what it is actually changing. who knows.... but i would never discount it without 100% proof. thats just being ignorant to act like u just know he's wrong. but on here...... its expected to c that response.

[CRAZY70MAN]

even though some people eat sleep drink 70's or think they do, or think they r god here which i personally think is more of the case, no one has posted dyno numbers. and no one has talked about the mods done in this case as in depth and what it is actually changing. who knows.... but i would never discount it without 100% proof. thats just being ignorant to act like u just know he's wrong. but on here...... its expected to c that response.

Some of Kasey's 70 builds look like God may have built them..........lol..........

[whyzee]

The most you could EVER get out of an 88cc air cooled 4 stroke would be around 8hp. Dyno was definitely off

Love your build though! Awesome work regardless of its HP.

[CRAZY70MAN]

Here is another dyno chart from Sterdy with an 88cc kit and their performance pipe. Tad over 5 hp. http://www.sterdyproducts.com/productcart/pc/viewPrd.asp?idcategory=38&idproduct=50

[Thorpe]

Well... ^^That helps make my decision, on doing a 88cc kit, or a lifan motor swap... Lifan it is!

[350xx]

Well... ^^That helps make my decision, on doing a 88cc kit, or a lifan motor swap... Lifan it is!

Exactly what I was thinking.
Lifan 125 with kickstart it is!
Make a custom lever for the rear fenders so its like a big red. (Swings up backwards) and we will be good to go!

[KASEY]

even though some people eat sleep drink 70's or think they do, or think they r god here which i personally think is more of the case, no one has posted dyno numbers. and no one has talked about the mods done in this case as in depth and what it is actually changing. who knows.... but i would never discount it without 100% proof. thats just being ignorant to act like u just know he's wrong. but on here...... its expected to c that response.


well i still after 32 years of riding 70's i still have the passion for them unmatched by 90% of you guys,, just ask me!!! i do not need a dyno to tell me anything,,, it would taks a specialized dyno to be accutate with these small hp motors,,, i do know that,,, and i can tell you with a pretty good amount of accuracy from the list of mods to his motor its not even close.... HOW you ask??? well lets talk about it,, first of all i see no timing advance,, you need alot of timing to use that amount of rpm's... stock 70 have NONE ,,, so when i built a 95cc 70 motor.. YEP 95 cc's you can go that big ,, with about 12 to 1 compression,,, i didn't use a stock 70 head either,, because it has no bearings on the cam,, and the betrice cam has very small diameter bearings ,, which help but at 10.000 rpm's hinder also,,, i used a xr70 honda head with large diameter bearings,,, the head was flow ported very nicely i also used a 24 mm carb not a 20,,,, more air more power at higher rpm's.. as far as timimg i used a ct 70 flywheel which has a built in centrifical advance much needed,, also the flywheel ia aluminum reducing rotating mass ,, after spending A buttload of money I installed it in a chassis to see what all the hard work had yielded,,,,, wow big power alright ,,, then i finished the install of the PITSTERPRO 155ho.... well the 95 cc build is on the shelf as much power as it did have ,,,,, the 155 seems to be DOUBLE THAT ,,,,,so believe me i have been around the block for many years with 70's everywhere from my garage to parts in the dishwasher,, so a dyno really means nothing to me... get me a video i will tell you all you need to know,,,, and if you want to build a HOT ROD 70 call me i will be glad to talk about it for hours!!!!!! OH and ITS OK TO USE MY NAME IN YOUR POST!! i have broad shoulders and i can take it ,, no sense in beating around the bush!!!

[TatTooL23]

believe me i do not discount the knowledge u have with 70's or any trike for that matter. its far more then i know. i read about and watch all the builds u do. they r great. i just disagree once in awhile on how people go about things. and i am not saying just u..... i know its how it is, and it won't change. just have seen it all too much on forums. i guess its just something that bothers me too much, or i think about it too much when it doesn't affect me in any way.

and i as well thought wow 16hp?? but i just didn't know 100% for sure. i understand now how u did know for sure.

anyway. i am starting two 70 builds. one basically a stock restore and hopefully a suspended 150cc for the other. we will c, lots of other projects at the moment, but i chip away at a little on each here and there.

[bigworm626]

We have a verdict: Kasey is God of the 70cc. Like they used to say in ECW... Holy Sh!t!!! Holy Sh!t.

[torque]

was doing some reading on the powroll sight found some good reading about dyno's. thought i would post it here

http://www.powroll.com/tech_specs_dyno.htm