refer to "Engines,Plugs,Tuning, Petrol, Turbines, Mufflers, Cleaning, etc"
sun section "Bearings, Metal Working, Mufflers, Tuned Pipes." for several
pages on Tuned pipes. e.g.
The Tuned Pipe - Modifying Your Engine
Tuned Pipes - FAQ - Andy Ellison
Tuned Pipe Designer - JavaPipe: - download calculator
Tuned Pipes - The Technology of (emphasis on RC cars/trucks)
Tuned Pipes - The mystery of - four part series + downloads
Regards
Alan T.
Alan's Hobby Model & RC FAQ Web Links
http://homepages.ihug.co.nz/~atong
> i am going to build a tuned pipe for my 28cc weed wacker motor that is
> going into a boat, im not sure how to measure the exhaust port
[quoted text clipped - 6 lines]
> the port starts to open and finish when the piston crown reaches the
> top of the port
john mc lucas - 20 Aug 2007 12:44 GMT
Duration is from when the exhaust port,
opens on the down stroke to when the piston
closes the exhaust port on up stroke.
Timing duration can be increased by removing
material from the top edge of exhaust port,till
required timing is achieved.Good Luck,
John.

Signature
john mc lucas