4stroke pipe on a 2stroke

[backwoodsracer]

Some one answerd this for me few years ago but what would happen if you took th fatty off and put a reg 4 stroke pipe on or vise versa?

[Brauap]

I have always wondered this and wanted to experiement but I simply do not have the $$$$ to do so! hah

I think a 4T pipe on a 2T would create massive torque because if you look at all the trials bikes that is the kind of pipes they have.. I am not sure a 4T could run on a 2T pipe due to the small exiting hole, unless it was either a small bore 4T or you modified it. But I think it would be create lots of top end power.. but I'm not sure on either! haha It would be fun to experiement on though!

[Honda#4]

Some one answerd this for me few years ago but what would happen if you took th fatty off and put a reg 4 stroke pipe on or vise versa?

It will sound like it has two extra strokes of power LMAO!

[wilkin250r]

2-stroke pipes are very particular in design. The fat section of the pipe is very crucial in creating power, it helps to remove exhaust gas, but probably more important, it helps keep the fresh fuel/air mixture inside the cylinder instead of letting it escape out the exhaust port.

A 4-stroke doesn't need this because it has valves. The exhaust valve closes, and that's what keep the fresh fuel/air inside the cylinder, it doesn't need a pressure wave coming from the pipe.

[honda400ex2003]

braap ding ding ding. braap ding ding ding...


sounds like a winner to me. who needs an expansion chamber.


steve

[ZeroLogic]

Originally posted by wilkin250r
2-stroke pipes are very particular in design. The fat section of the pipe is very crucial in creating power, it helps to remove exhaust gas, but probably more important, it helps keep the fresh fuel/air mixture inside the cylinder instead of letting it escape out the exhaust port.

A 4-stroke doesn't need this because it has valves. The exhaust valve closes, and that's what keep the fresh fuel/air inside the cylinder, it doesn't need a pressure wave coming from the pipe.

Exactly, it will not work. The motor will run but it will have no power.

[jcs003]

two stroke pipes are tuned by trial and error for specific applications. i.e. XC racing, MX, drag, duning...etc.

a race two stroke engine probably has triple the time invested in R&D for pipe, port, carb and intake than any four stroke race engine.

cam design can be done solely with a computer program. port layout isnt necessarily done in a fundamental fashion. some guys do it just by experience through R&D. others, take info from a computer and apply with simple rotary tools.

all this is playing a role in two stroke pipe development. on a four stoke it basically comes down to diameter and type of silencer clambering a pipe is using.

[krt400ex]

Originally posted by wilkin250r
2-stroke pipes are very particular in design. The fat section of the pipe is very crucial in creating power, it helps to remove exhaust gas, but probably more important, it helps keep the fresh fuel/air mixture inside the cylinder instead of letting it escape out the exhaust port.

A 4-stroke doesn't need this because it has valves. The exhaust valve closes, and that's what keep the fresh fuel/air inside the cylinder, it doesn't need a pressure wave coming from the pipe.

couldnt have said it better. without an expansion chamber, a kx250 will run like an xr100

[Brauap]

How to the trials bikes run?? I honestly do not know.. is it all in the porting?

[wilkin250r]

I don't know about all trials bikes, but I know the Gas Gas is a popular one, and it's a 4-stroke. It LOOKS like a 2-stroke because it's a side-valve engine.