X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4951953 for flyrotary@lancaironline.net; Wed, 20 Apr 2011 08:59:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=2vPzMgfOIErJN3e9oB0C+rg2PyH4jEtKOmutOqWodeY= c=1 sm=0 a=B-AW_4qdGpYA:10 a=8nJEP1OIZ-IA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=HHGDD-5mAAAA:8 a=Ia-xEzejAAAA:8 a=7g1VtSJxAAAA:8 a=5attzAUJ4iV1dye-tQIA:9 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=i1zE5R4R5dEA:10 a=EzXvWhQp4_cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:51800] helo=EdPC) by cdptpa-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 3C/7E-01460-C78DEAD4; Wed, 20 Apr 2011 12:58:36 +0000 Message-ID: <14E40669222A4659A180479DF476D31B@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Burns Stainless Muffler Failure Date: Wed, 20 Apr 2011 08:58:27 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 Hi Thomas, Thanks for the photo. The exhaust pulse from the rotary is just incredible powerful. Any flat surface perpendicular to the pulse (such as the end of you muffler), appears to be doomed to fatigue failure from the pounding of the pulse. I once squished the tips of 2" dia SS steel tubes together and drilled holes to make a "fishtail" sound suppressor. After a 30 min flight, I came back to find chunks of the SS tube missing where the pulse had hammer and fatigued the tips during that short flight. Rather than a flat surface, a cone or angle surface which deflects some of the pulse energy appears to be required for longer term survival. Better luck on your next choice Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com -------------------------------------------------- From: "Steve Thomas" Sent: Tuesday, April 19, 2011 7:24 PM To: "Rotary motors in aircraft" Subject: [FlyRotary] Burns Stainless Muffler Failure > I just did an inspection of my muffler and found that it was basically > coming apart inside. This is a Burns Stainless, 17" 2-Stage muffler after > 50 hours of flying behind a 2-rotor engine. Now, it could be that 50 > hours is a reasonable life for something like this, I don't know. But, it > certainly confirms the stories of muffler disintegration. I've inspected > this muffler several times over the last 50 hours, but this is the first > time that I've seen damage. But, when it comes apart, it really comes > apart. It is unfortunate, as the muffler was really effective in reducing > the noise and was light-weight. > > > Best Regards, > > Steve Thomas > > _____________________ > > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html >