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Date: Tue, 10 Jun 2008 09:17:38 -0400
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Exhaust and Muffler designs.
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Al Wick wrote:
> Well written Al, lot's of good info. I'm a little concerned for your 
> rear bracket. If you kick exhaust on your car, you will see it is soft 
> mounted. Typically the tail pipe can move up to 1/4" or more. Hard 
> mounting forces stress concentration at the attach point. 
I think you're comparing apples and oranges, Al W.

The tailpipe on a car is connected to the frame, which moves relative to 
the engine.  Al G.  has his firmly attached to the PSRU.  If it moves 
relative to the engine, then I don't think he'll be worrying about his 
muffler much.  Looks like the way he has it mounted, there would be some 
longitudinal flexing to allow for heat expansion of the pipe, but it 
would be very resistant to any vertical movement relative to the 
engine.  A soft mount would be counterproductive in this case.