GY6 A vs B Engine Discussion Which Is Best?
 

I thought it would be an interesting topic to discuss what the differences are, benefits or disadvantages of swapping to a B short case 57mm over the A 54mm.

Can the b be stroked? I have heard they can't.


Seems that starting with the B 57mm has a lot of capability of big, big bore.

Here is a sample of the b I have seen:

https://chinesescooterparts.com/prod...ne-assembly-2/

ur better off with a taida kit

http://shop.martinmopeds.com/Taida-G...Y6-A-01-63.htm

Problem with that one is it needs alot of parts to complete which is pretty expensive in comparison.

From my understanding the main difference comes down to how much you can bore and stroke 'em. The second is price. Guys have one that can be bored and stroked they charge more for it.

I didn't ever research into the tiny differences. As far as I know the mounts and/or reinforcement webbing could be totally different also.

Unless it is the expensive Taida, it appears the b cases have internal reverse. So far by my research all the performance parts such as clutch, variator, carb, intake are the same.

The A has the 54mm bolt spacing boreable to 63mm but safely to 62mm.

The B has a 57mm bolt spacing boreable to 67mm and 232cc.

I have heard though that you can't stroke the B block as the crank would interfere with the reverse mechanism. Anyone know on this?

I am starting to be more sold on going with a CF250 that has the high, low, reverse, neutral. It has more hp out of the box and a much larger variator which I believe would help a lot on top speed.

The low gear would help on climbing as well and it appears there a quite a bit of performance parts now on the market for the 250.

My views on it also. Would have been the route I taken if I didn't have the atv drive train given to me.

Today I had somebody offer me a rusted out geo metro with a good drive train for $100. I'm shopping for a 1.5 inch bender die now. 55 horses with 58 ftlb torque should be able to turn over some 32-10-14 inch silverbacks no problem:evil:

When talking about the metro "good" is a relative term lol.

that will be too big of an engine to fit wouldn't it?

Yeah on a paved road good is the last thing I would use. In a buggy thats a good bit of power considering the gy6 makes about 10hp and the cn250 is rated at 18hp. The key is designing the cage strong enough but doesn't weigh more than the car (around 1900lbs). My target is 400-500lbs finished weight, about 140 of that being engine/trans. Push come to shove it seems it's pretty easy to tune the little suzuki 1.0 to 75 reliable horses. Still got 2 more major projects in front of it so it's got a minute to sit in the planning stages.


Geo engine swaps:

http://buggynews.com/suzuki-1000cc-g...gy-t29580.html

http://www.buggymasters.com/forum/showthread.php?t=1155

Not that completely crazy swap.

I think an atv engine would be best because the car engine would be so much fab work.

I road on a rzr 1000 a few weeks ago and it had tons of power. However, when it is all said and done, we were plenty fast at 45mph and on trails 40 was scary.

These buggies even with the gy6 150 stock will kick butt on the rzr going through trails. It is the wide open that would be completely opposite or climbing.

Speed and these don't really mix:

http://www.louisianasportsman.com/cl...5663985688.jpg

Those need power to keep the spinning in the muck to keep the treads open and grabbing. Not the exact thing you get from gearing but simple displacement. The atv engine buggy which is next on the project list is the trail/joy riding machine. The one I follow my son around in his gy6 powered one.


But what do I know my daily driver is a s10 with a v8. I like little vehicles with big engines.

I know what you mean. I have a supercharged 4.7L V8 Jeep Grand Cherokee

sounds like a Joyner would be a better machine possibly.

A better machine would most likely be a small tracker, samurai, or side by side but this is just a hobby to keep me from going crazy sitting all day. I've already built a 4x4 s10 blazer sitting on dana 60 axles with a 383 stroker. I was wanting to exocage it with 1.5 and this is another reason to buy the bender die for my jd2.

Plus adult buggies of any make are rare as hens teeth around here. This kinroad I have was the closest I could find and it was an 8 hour round trip to go pick up after a 2 year search.

I am currently doing so modifications to our buggies as well and want extra power.

so any other opinions of the a vs b case being that the b case has internal reverse and can be bored and stroked to 232cc.

the taida B case does not have reverse dont know what engines you are lookig at ? Taida makes both a short case and long case in the b block. Comes with a wider stud spacing. The 232cc you would have to use a long case. The buggies use a short case unless you dont mind modifying.

jmansracerocket,

There is an ATV/Buggy Gy6 200 B shortcase on the market. It can be bored up to 232 just as Taida.

It also has a larger variator of 123mm.

It also includes a built in oil cooler drilled into case.

I understand that even with taida, 232 is race only and not reliable for daily use.

It appears from study that 180cc which has a 3mm stroker, is about the biggest we can go for reliability.

That Gy6 is a qmk engine it’s not the same quality case. You can get a 180cc and add a stroker crank I believe even bigger then 3mm, but that’s with taida short case with the wider stud spacing of 57mm not our stock 54mm. Your going to spend some coin for taida stuff but there quality is better.

jmansracerocket,

I know the case would not be the same quality of Taida. However, I would think if I used the Taida bearings, Cylinder with Forged Piston, Big Valve Head and Stroker crank all by Taida would be durable.

What is the biggest bore and stroke you think I could safely and reliably get away with?

Well that’s a big question because are you going to stay with the shortcase ? Also from what I’ve realized the cranks are not balanced ! There’s a few places that will send the taida crank out for balancing but of course more $$ again. But with that the engine will run smoother, and last longer, and be more reliable espically increasing the stroke that’s very important. It honestly comes to your budget and what your willing to spend. The taida engines get expensive quick.

The taida cranks need balancing? I thought they were top notch cranks.

Yes on the short case not long.

Taida crank is still better quality then the smaller stroker cranks from what I’ve seen. There’s combo kits where u can purchase a b block taida setup shortcase and it’s a 63mm piston and uses a taida stroker crank. Uses a oil cooler also. Just I would recommend a better starter clutch at least. Could try stock starter but might not be a bad idea to upgrade the starter as well.

Jmans,

Was talking about keeping the Chinese b case as they are being that it has internal reverse and the wider 57mm pattern, but put Taida crank, cylinder, piston and head.

That qmk Chinese engine uses a 61mm piston. So u would have to tear down the engine and bore it to accommodate a 63mm piston if that’s what u want. Or leave it as a 61mm and put a stroker crank in it. But there’s more then just adding parts. You have to check valve clearances also, and see what chain length you will need.

Jmans,

From my understanding, it appears that the parts are interchangeable with the Taida parts.