Jerry Hey wrote:

Is there a significant performance gain with the tuned version?  I
have got the impression that exhaust pipe length is not so important
as unrestricted breathing.    Has anyone built one of these mufflers?
Is the simple version just an empty can that the exhaust dumps into
from the side?   What type of Stainless?  Is ".040 inconal" a
complete specification?   Jerry

In theory yes Jerry on the tuned version. Not to my knowledge has any
one built one yet. I am not sure it would fit in your cowl as the diameter
is about 10 inches while the engine is about 6 inches from center line
so the width of the cowl in that area would have to be about 32 or more inches
wide. Brian Trubee designed a simplified version with square runners welded
up from flat sheet that you might want to try. It is possible to make it
slightly more compact as the runners could be rectangular.

Just an empty can. .049 thick 316 stainless ought to be about right.
0.065 thick 316 SS would probably make it bullet proof.
Inconel (pure nickel and chrome) is great but expensive.

Paul Lamar

Bill Freeman wrote:

Paul,

I would recommend 321 or 347 over 316 due to the formation of
chromium carbides at temps between 850F and 1600F.  The 316 will
WORK fine, but will be susceptable to severe corrosion when at room
temp and exposed to humid air after sensitization , i.e. a time at
the "no-no" temps.  301 thru 304, 316 and 310 all behave this way.  321 is
stabilized with titanium and 347 with columbium.  Most A/C exhaust
systems are 321.

Bill

Ah So! That is why some of those cheap SS boat fittings parts rust 
around the weld! Thanks Bill.

Paul Lamar
 
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