X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [208.80.144.20] (HELO mail.royell.org) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTPS id 4221902 for flyrotary@lancaironline.net; Wed, 14 Apr 2010 21:28:30 -0400 Received-SPF: error receiver=logan.com; client-ip=208.80.144.20; envelope-from=dvanwinkle@royell.org Received: from IBM04421E67337 ([208.80.148.124]) by mail.royell.org (Royell Mail Server) with SMTP id XFQ30152 for ; Wed, 14 Apr 2010 20:27:52 -0500 Message-ID: From: "Dean Van Winkle" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Mistral Muffler Date: Wed, 14 Apr 2010 20:27:52 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0045_01CADC10.F546B640" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 100414-1, 04/14/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0045_01CADC10.F546B640 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Lynn and others on the Mistral Muffler According to the Mistral Team at Oshkosh 09, the Muffler shown in the = current photos is not the one that failed but a secondary down stream = muffler that plugged over time and eventually brought the Florida test = aircraft down. The muffler in the various photos is substantially = composed of inconel, gage unknown to me. I was hoping to use this = muffler for my 13B and Conversion Concepts Mount for my RV-9A, but a = cardboard template that I took to Oshkosh showed that the connector = flange on the outlet would almost touch the left rear rubber mount. I = do have the Mistral Intake Manifold that adapted quite readily to my '89 = NA 13B.=20 Dean Van Winkle 13B, RD-1B, EC2, EM2 dvanwinkle@royell.org =20 ----- Original Message -----=20 From: Lynn Hanover=20 To: Rotary motors in aircraft=20 Sent: Monday, April 12, 2010 6:47 PM Subject: [FlyRotary] Mistral Muffler Ernest,=20 =20 Copy you on that! What material type and thickness was the Mistral = muffler? Anyone know what their design was like? I know that something = fatigued and plugged the flow, but I never saw a drawing of their = muffler or had anyone explain how the failure actually occurred. It = could have been a baffle plate that was not well supported on all sides. = I don't see how that could happen to my muffler as the tube is welded = to both end plates and the exhaust gasses don't strike the tube directly = but swirl around it. Yes, a piece may fatigue over time and crack off, = but I can't imagine how it could plug up the exhaust path. But I guess = anything is possible if Murphy has his way. I'll keep a close eye on it = though. With a little finessing, I'm pretty sure I can get my little = inspection camera up the tailpipe. If that fails, I can remove one of = the O2 sensors and stick the camera through the hole for a peek inside. = =20 Mark =20 =20 Here is one version of the Mistral muffler. Said to be the failed = version. Well thought out. Superb exicution. Note that there appears to = be a slip join in the main body between the flanges. The whole muffler = is encased in a cooling sleeve with a big blast tube on one end and a = coaxial exhaust areounf the down pipe.=20 =20 My vote for the failure point is the flat disc closing the end of the = perf tube.=20 =20 Nothing flat survives the pounding. If its flat it dies. Round, = conical or spherical, yes. Flat no. =20 Lynn E. Hanover=20 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0045_01CADC10.F546B640 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Lynn and others on the Mistral = Muffler
 
According to the Mistral Team at = Oshkosh 09, the=20 Muffler shown in the current photos is not the one that failed but a = secondary=20 down stream muffler that plugged over time and eventually brought the = Florida=20 test aircraft down. The muffler in the various photos is substantially = composed=20 of inconel, gage unknown to me. I was hoping to use this muffler for my = 13B and=20 Conversion Concepts Mount for my RV-9A, but a cardboard template that I = took to=20 Oshkosh showed that the connector flange on the outlet would almost = touch the=20 left rear rubber mount.  I do have the Mistral Intake Manifold that = adapted=20 quite readily to my '89 NA 13B.
 
Dean Van Winkle     = 13B, RD-1B,=20 EC2, EM2
dvanwinkle@royell.org &nbs= p;=20
----- Original Message -----
From:=20 Lynn=20 Hanover
Sent: Monday, April 12, 2010 = 6:47=20 PM
Subject: [FlyRotary] Mistral=20 Muffler

Ernest,
 
Copy you on that!  What = material=20 type and thickness was the Mistral muffler?  Anyone know what = their=20 design was like?  I know that something fatigued and plugged the = flow,=20 but I never saw a drawing of their muffler or had anyone explain how = the=20 failure actually occurred.  It could have been a baffle plate = that was=20 not well supported on all sides.  I don't see how that could = happen to my=20 muffler as the tube is welded to both end plates and the exhaust = gasses don't=20 strike the tube directly but swirl around it.  Yes, a piece may = fatigue=20 over time and crack off, but I can't imagine how it could plug up the = exhaust=20 path.  But I guess anything is possible if Murphy has his = way.  I'll=20 keep a close eye on it though.  With a little finessing, I'm = pretty sure=20 I can get my little inspection camera up the tailpipe.  If that = fails, I=20 can remove one of the O2 sensors and stick the camera through the hole = for a=20 peek inside. 
 
Mark 
 
Here is one = version=20 of the Mistral muffler. Said to be the failed version. Well thought = out.=20 Superb exicution. Note that there appears to be a slip join in the = main body=20 between the flanges.  The whole muffler is encased in a cooling = sleeve=20 with a big blast tube on one end and a coaxial exhaust areounf the = down pipe.=20
 
My vote for the failure point is the flat disc closing = the end=20 of the perf tube.
 
Nothing flat survives the pounding. If = its=20 flat it dies. Round, conical or spherical, yes. Flat = no.
 
Lynn E.=20 Hanover=20

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