Pipe design for my modified Kawasak H1

View previous topic View next topic Go down

Pipe design for my modified Kawasak H1

Post by jeff kushner on Tue Jun 09, 2015 6:01 pm

I'm hoping the Admin will see this since there doesn't appear to be a lot of traffic even though you have dedicated a lot of time to building this forum. Your work is commendable for all you've written on 2 stroke chamber design. I have been building high performance two strokes for 30+ years but this is my first foray into pipe design. I had a friend with the MOTA program run some numbers on a set of "fat" pipes and he told me that without tapered headers, they were next to useless....BUT, with tapered 44mm headers expanding to 55-58 over the course of 300mm or so, the power went through the roof when coupled to an engine with a exh duration of 200+ degrees.

Do you have any way to check this for me, or for the tools that I can verify it myself before I begin cutting up and re-welding these pipes? I need to remove the tapered headers from an old set of pipes and graft them to the "fat" pipes.


Thanks,
jeff

jeff kushner

Posts : 1
Join date : 2015-06-09

View user profile

Back to top Go down

Re: Pipe design for my modified Kawasak H1

Post by Rx7man on Sun Jul 12, 2015 2:25 am

Hello.. sorry I'm of no help to you.. yet... but I figure we have a bit of a dust bowl in here.. no better way to fix that than to say hi Wink

Rx7man

Posts : 9
Join date : 2015-07-11

View user profile

Back to top Go down

Re: Pipe design for my modified Kawasak H1

Post by Admin on Sun Jul 12, 2015 2:16 pm

Mota is a more advanced program and so I would go with its suggestions. Please let us know the outcome

Admin
Admin

Posts : 13
Join date : 2015-03-28
Age : 60
Location : Asuncion, Paraguay

View user profile http://www.dragonfly75.com/motorbike/ECtheory.html

Back to top Go down

Re: Pipe design for my modified Kawasak H1

Post by Morehp on Sun Oct 18, 2015 1:04 pm

44 mm header is WAY too big for 166 cc. You have to be careful what inputs you use on sim programs like Mota, you have to be realistic. Garbage in = garbage out. What is the window area of your exhaust port? What is the peak hp rpm?

Morehp

Posts : 3
Join date : 2015-10-18

View user profile

Back to top Go down

Re: Pipe design for my modified Kawasak H1

Post by Rx7man on Sun Oct 18, 2015 1:31 pm

48mm is a BIG header pipe on a 168cc... I would expect something more along the lines of 38mm tapering to 45 over 300...

also, a 200* exhaust duration (if it doesn't have any power valves, etc) is going to lose serious torque and it doesn't have a whole lot of displacement to make up for it... it would certainly scream at the top end though

and I agree that simulation programs are Garbage in, garbage out.

Rx7man

Posts : 9
Join date : 2015-07-11

View user profile

Back to top Go down

Re: Pipe design for my modified Kawasak H1

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum