Mailing List Message #65366
From: Finn Lassen <>
Subject: Re: [FlyRotary] Re: Mufflers
Date: Tue, 19 Nov 2019 09:42:16 -0500
To: Rotary motors in aircraft <>
Finally took a picture. Actually only the last half of the 3 foot pipe has holes.
The "fish mouth" is not. It's just the pipe squeezed and welded shut.
That skin seam is at the rear cockpit bulkhead in the RV-3B.

I see the last few holes have stuff in them. Probably more innards from the muffler. Will have to take it off and clean it out.

If I'm going to have to do the same on the RV-4, it's going to be a heck of a long pipe (heavy).


On 11/18/2019 8:27 PM, David Leonard wrote:
Spintech was the quietest I used,but it clearly robbed me of LOTS of power, so I took it off.  Flowmaster worked second best, but only for a couple of hours until all the packing fell out.  Removed that one too.  Running a long pipe to behind the seating area is acceptable.  Thinking about trying multiple 1/8 holes like someone else described.

Also tried a race muffler from Burns Stainless with little effect.

Dave Leonard

On Mon, Nov 18, 2019, 1:20 PM Neil Unger <> wrote:
Attn Todd Bartrim,

                                       When in doubt check the
instruction book!!  I finally checked the archives to find that Todd you
are way in front of me.  I am definitely going to put a turbo on my
renesis, but am still looking for a muffler. Depending on what Lynn
suggestes, but your experience with the spintech or your latest version
is appreciated.  Do you have any tests with a decibel meter?  My exhaust
noise is just too loud, fine for me but passengers do not exactly que up
for another ride.

So design starts all over again, but I do have another engine to play
with to keep mine in the air while I experiment.    Here again Todd you
have the electric water pump --- thoughts?


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