What I was thinking is sort of similar with the following exceptions-

two

exhaust runners joining into one 31  inches back from the exhaust ports,
using one of those stainless exhaust bellows to connect to the

perforated

pipe. The holes in the perforated pipe would be louvered to face the

rear by

putting a rod into them and bending them. That way they would scoop into

the

exhaust flow and scoop the flow out of the perforated pipe. The perf

pipe

would be surrounded by a 5" dia pipe that was open on both ends. The

forward

end could take air out of the engine compartment or the heated air from

the

radiator, if care was taken not to radiate heat from the exhaust to the

rad.

My  2 cents.
Brian Trubee

Sounds like you may get some exhaust augmentation of airflow through your
cowling.   Be interested to hear how it works.  I intend to louver my holes
the way you describe, but with 520 holes to do the day before I took off for
Sun & Fun, just did not get to them.  I also am considering having the tubes
coated with the high temp ceramic coating (which I am told will reduce
outside pipe temp to around 300F) in order to protect the paint job.

Then I need to find something that will withstand the shock wave of the
exhaust pulse to make "Fishtails" out of.  The 0.035 stainless steel
material I have used only survives a few minutes at full throttle.  The
pulse shock wave simply fatigues the metal in a matter of minutes and chunks
actually fall off.

So glad to see folks experimenting with the mufflers so hopefully we will
close on a couple of good solutions.

Ed Anderson

 
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