Mailing List flyrotary@lancaironline.net Message #57723
From: Steve Thomas <glasair2@me.com>
Subject: Re: [FlyRotary] DNA Muffler
Date: Sun, 08 Apr 2012 13:12:34 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hey, Bill

Regarding the DNA Muffler, I was able to procure one and install it on my exhaust some time last year.  It is the Full Throttle Collector model.  Just wanted to let you know it was essentially worthless.  The exhaust note was so loud that I could not squelch my intercom.  After turning the intercom volume down, it was still too loud for my Lightspeed Zulu to make me comfortable.  I'm in the process of scavenging some 321 tubing I had it welded to, and after that, I'd be happy to ship it to you.  

I am quite frustrated with the whole muffler thing.  The only one that had a decent quieting capability, a Burns Stainless 2 stage unit, was blown apart after about 30 hours.  I could have had a blockage if not caught.  

My latest attempt is to use the Racing Beat presilencer and universal muffler.  These units are oval in shape and don't have the same clearance problems of some, but may be still too big for your application.  I'll let you know how it turns out.  

Best Regards,

Steve Thomas

_______________________________________________________





On Apr 8, 2012, at 9:51 AM, Bill Bradburry wrote:

I really don’t want to redo the exhaust, but I think I have little choice.  I only have about a half to three quarter inch of clearance between the exhaust and the cowl.  I have a piece of heat insulation glued to the cowl and a piece of thin SS clamped to the exhaust, but it looks like in flight, the engine moves slightly to the left and causes the exhaust to touch the cowl. 

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of downing.j@sbcglobal.net
Sent: Sunday, April 08, 2012 12:36 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: DNA Muffler

 

Bill, If you don't care to redo the exhaust, I installed a sheet of .016 SS on 1/8th Fibre Frax, this happens to be 11 x 42 inches long and saved my fannie when I had the engine fire, to protect the fabric on the belly of my Wittman Tailwind.  The rebuild is coming along and the Marcotte Re-drive has been fitted with a seal retainer and a cooling system for the gear oil is being developed.  JohnD,

----- Original Message -----

Sent: Sunday, April 08, 2012 10:08 AM

Subject: [FlyRotary] DNA Muffler

 

I don’t think this muffler is available for sale anymore.  Does anyone know of a source for it?  I am particularly interested in the one they call the “Full Throttle Collector”, because it is only 4” in diameter and I am space challenged.

 

My plane is being painted and I think the exhaust is too close to the cowl and will cause a burn in the paint, so I plan to rebuild the exhaust when I get it back and would like to include this muffler if I can find one.

 

Any help would be appreciated.

 

Bill B


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