With a  rash of loss of power episodes, and with the lack of a definite
cause, and  with a common
thread being that they had a Hushpower muffler, I'm thinking  of either or
both of these options- rip
the guts out of my current  hushpower muffler, or design and build a
muffler that is the same
dimensions as the Hushpower. It needs to have a 2" inlet be about 18"
long, and be no wider than 4
1/2 inches in diameter. I'm thinking of  ordering or making  2) 2 inch to
4 inch transitions made
from  .065 321 stainless, with a center section that is cylindrical. I want
something that is not
going to have it's guts blow out and obstruct the  exhaust flow and kill
power. It should also
attenuate the exhaust note to  some degree.

When I last checked my Hushpower, I took it off and it  rattled like a baby
rattle. I used a flexible
camera and both inlet and  outlet cones were intact. Still, this muffler is
the thing that makes me
most nervous about my installation.

Any ideas for the internal  design of a muffler that is the same rough
dimensions as my hushpower,
but  is somewhat failure tolerant?

I have one of those cylindrical SS  mufflers made in Canada, I forget the
name of the manufacturer,
but it is  cylindrical and about 24 inches long. It has angle  pieces
welded across  the cylinder part
in a spiral pattern.  I might just cut it and  shorten it to fit.

Thanks,
Brian Trubee



Is Boeing surplus still up there? If you can get some inconel that would
be a way
to go. .065" 321 SS is pretty good. I would design it in two pieces  and
bolt them
together with 1/4 inch SS bolts. That way you can take it apart  from time
to inspect it.

Paul Lamar
--

Select a tubing size that just slips into the outlet  of the muffler.

Weld two half loops of rod stock in the end of  the tube, that extend as
far as possible into the muffler. Retain in the exit  tube with a single
stainless bolt.

Any single piece of muffler swarf now has no smooth  surface to seal
against in order to completely block the exit. Smack the muffler  as part of each
preflight to be sure nothing is adrift  inside.

Lynn E. Hanover