Mailing List Message #67380
From: Charlie England <>
Subject: Re: [FlyRotary] Re: Fun with AI for the rotary
Date: Fri, 3 Feb 2023 15:31:58 -0600
To: Rotary motors in aircraft <>
For some reason, it's hard for me to believe that PL designed the Swiss Muffler. ;-)
Note that this page is an excerpt from the Tony Bingelis book Firewall Forward, and I'm pretty sure that Bingelis was passing on knowledge picked up from the Europeans, that needed really quiet a/c to pass certification.


On 2/3/2023 2:00 PM, bruce buksyk wrote: has posted all the old PL files.


This is probably the exchange you are looking for.


Scroll to the bottom of the thread for pics/links.


This is the Index for all the older files.




Sent from Mail for Windows


From: Les C
Sent: Friday, February 3, 2023 1:05 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fun with AI for the rotary


Since the PL site doesn't have any of the old information, it would be great if somebody could post that here.


Les Criscillo
Pilot, Brewmaster, Maker

From: Rotary motors in aircraft <> on behalf of Marc Wiese <>
Sent: Friday, February 3, 2023 9:03:14 AM
To: Rotary motors in aircraft <>
Subject: [FlyRotary] Re: Fun with AI for the rotary


I think I have that PL design too. But I didn’t think it included any inner packing of any sort?


Sent from my iPhone

On Feb 3, 2023, at 9:23 AM, Le Roux Breytenbach <> wrote:

I have a design of the “late Paul Lamar“ somewhere in my archives.

Don’t know if i may share it on the group ?

That was of a proposed design of a freeflow muffler for rotaryengines.

He shared it with all the people on the group.

Don’t know if it was patented?


Let me know


Le Roux


Sent from my iPhone

Le Roux Breytenbach 

On 03 Feb 2023, at 14:53, Doug Lomheim <> wrote:

So where can we find the proposed “specialist in exhaust systems” that it suggests?  For our applications that would probably be someone on this list!?     :)





Designing a muffler for a Mazda rotary engine requires taking into account several factors, including:

  1. Engine specifications: The muffler must be compatible with the size and output of the engine.
  1. Noise reduction: The muffler should reduce engine noise to an acceptable level, while also allowing the engine to function efficiently.
  1. Performance: The muffler should not restrict exhaust flow and impact engine performance.
  1. Durability: The muffler must be durable and withstand the high temperatures and vibration generated by the rotary engine.

A muffler design for a Mazda rotary engine could include a straight-through perforated core, surrounded by sound-deadening materials such as fiberglass or ceramic wool. The muffler should be mounted using flexible connections to reduce vibration and ensure a secure fit. Additionally, heat shields could be used to protect the muffler from high temperatures.

These are general guidelines and the exact design may vary based on specific engine and performance requirements. Consulting with a specialist in exhaust systems is recommended to ensure a muffler that is optimized for your specific engine and application.

You're welcome. 
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