X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao103.cox.net ([68.230.241.43] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTP id 2962270 for flyrotary@lancaironline.net; Tue, 10 Jun 2008 20:21:32 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.43; envelope-from=alventures@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao103.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080611002044.KNFS1276.fed1rmmtao103.cox.net@fed1rmimpo03.cox.net> for ; Tue, 10 Jun 2008 20:20:44 -0400 Received: from BigAl ([72.192.137.74]) by fed1rmimpo03.cox.net with bizsmtp id cQLt1Z00A1cVYgg04QLtEq; Tue, 10 Jun 2008 20:20:53 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Exhaust and Muffler designs. Date: Tue, 10 Jun 2008 17:20:54 -0800 Message-ID: <000001c8cb61$653c5c60$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 I'd put thin layer of rubber between your clamp=20 and the psru. Same concept at harmonic damper on engines. In theory it = would reduce stress concentration at your muffler outlet. FWIW -al wick ------------------- That makes some sense to me. Although I'm not sure what sort of = material one would use since the temps on the re-drive can get over 200F. And = there is the possibility of making things worse - things have been fine for = 100 hours and no signs of any "movement" at the clamps. Adding some = flexibility would change (lower) resonance frequency and . . .=20 My thinking is the critical weld is not at the end of the resonator; but = the ones at the header/tangential muffler joints; but I could be wrong. Al Gietzen