Mailing List Message #65378
From: Marcus Wiese <>
Subject: Re: [FlyRotary] Re: Mufflers
Date: Wed, 20 Nov 2019 07:38:48 -0600
To: Rotary motors in aircraft <>
Just remember the Mistral muffler event. The muffler caused the Piper Arrow  (?) with their rotary to crash after the internals blocked the outlet and led to power loss. It may have partially led to their withdrawal from the engine/PSRU market. To all our loss.

Sent from my iPad

On Nov 20, 2019, at 12:28 AM, Matt Boiteau <> wrote:

This is the Aero Exhaust 2525XL diagram. I have one, but left it in Canada. Will bring it back with me in Jan to try at taming the exhaust again.

- Matt Boiteau

On 2019-11-19 3:23:50 PM, Charlie England <> wrote:

On Mon, Nov 18, 2019 at 11:57 PM Andrew Martin <> wrote:

Kelly, I would if I had some, really did not expect it to work as I deviated from the design a bit. Will be back at airport on weekend to take photo, too late for construction photo. But nothing to it.

I read about the idea by Gary Schwarz in this thread, post #7 , post #58 for his testing and post #142 sums up his findings.
Someone on here may know him as he was doing it for a rotary. Mine is much shorter than his drawing below due to space constraints but the theory works.
edit: Ahh!!! deleted his picture as too big to post. it is in his post #7 mentioned above though.

That looks a lot like a simplified version (one less turn) of a standard automotive muffler.
The Aeroturbine tries to achieve similar effect (without the flow reversals) by using venturi effect to suck part of the exhaust around and then back into the central tube.


Archive and UnSub:
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster