4 stroke stroke exhaust desing ??

[robin]

what is the best way to calculate the correct id ? and best length ? for the most power ?

 

[jr dragster T]

It depend's on what you want realy. If making a staged exaust for a stock brigg's or clone the largest size should not exceed 1 1/2". I'd go 1"-1/8" Then maybe another stage slighter larger. It's realy all a experiment.

 

[robin]

all i no is that if you get the righ lenth pipe the exhaust will help suck out the burnt fule an air i dient no if ther a a valvulation a a rule to do with valve sises and rpm ?

 

[jr dragster T]

Well you dont want the pipe any larger than the port. So even 1 1/8" ID is the biggest I'd go actually.

 

[robin]

so should i keep the pipe the same as the size of the valve or the port from the engine btw it is a bike the inter net says max power is at 9000rpm i will take the head off and messure the valves engine will length matter

 

[modelengineer]

Well you dont want the pipe any larger than the port

Why? I'd say you don't want any pipe smaller than the port. You don't want to restrict the engines ability to expel exhaust.

 

[robin]

but if its to big you don't have a good exhaust velocity

 

[jr dragster T]

Yeah it's true. You dont want the pipe to be larger than the port by a whole lot.

 

[modelengineer]

I think you'd be safe going with a pipe that is exactly the same diameter as the port. That way everybody is happy

 

[BradenM]

Thats what I did, sounds and drive's happier now