Return-Path: Received: from email.netonecom.net ([209.172.26.13] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2993694 for flyrotary@lancaironline.net; Sun, 15 Feb 2004 22:52:00 -0500 Received: from johndown (C03-080.netonecom.net [216.65.186.80]) by email.netonecom.net (MOS 3.4.2-CR) with SMTP id CKJ07120; Sun, 15 Feb 2004 22:51:59 -0500 (EST) Message-ID: <010901c3f439$b8bcccc0$44bc41d8@johndown> From: "john" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] muffler? Date: Sun, 15 Feb 2004 23:01:43 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00E5_01C3F417.AE3A7E40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 This is a multi-part message in MIME format. ------=_NextPart_000_00E5_01C3F417.AE3A7E40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit MessageRusty; One of the Tailwind fellows is running his second 90 degree elbows into a three inch square tubing, fabricated of 321 ss. This square tubing will exit out the bottom of the cowl the same as the normal round exhaust pipe. I'm thinking of doing this, as it save alot of weight. JohnD From: Russell Duffy To: Rotary motors in aircraft Sent: Sunday, February 15, 2004 1:55 PM Subject: [FlyRotary] muffler? Greetings, I'm working on mounting this 14 pound Spin Tech muffler, and just have to ask a question... I know that rotaries are painfully loud with no exhaust on them. I also know that the cast manifold alone will help significantly, and that a turbo will reduce the noise to about normal Lycoming levels. As I understand it, this is partly due to the fact that there are twists and turns that the exhaust has to negotiate, which reduces the speed, and eliminates the supersonic pulses. As it turns out, my primary pipes will have to make three 90 degree turns before they get to the collector. I've started wondering if these three turns are enough to reduce the noise to an acceptable level. My gut feeling is that it won't be enough, but I think some people are already running with little to no muffling. I sure would like to eliminate that muffler, but I'm not optimistic that it will be possible. What do you think? Silly idea? Cheers, Rusty ------=_NextPart_000_00E5_01C3F417.AE3A7E40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Rusty;  One of the Tailwind = fellows is running=20 his second 90 degree elbows into a three inch square tubing, fabricated = of 321=20 ss. This square tubing will exit out the bottom of the cowl the = same as the=20 normal round exhaust pipe.  I'm thinking of doing this, as it save = alot of=20 weight.  JohnD
From:=20 Russell=20 Duffy
Sent: Sunday, February 15, 2004 = 1:55=20 PM
Subject: [FlyRotary] = muffler?

Greetings,
 
I'm working = on mounting=20 this 14 pound Spin Tech muffler, and just have to ask a=20 question...
 
I know that = rotaries are=20 painfully loud with no exhaust on them.  I also know that the = cast=20 manifold alone will help significantly, and that a turbo will reduce = the noise=20 to about normal Lycoming levels.  As I understand it, this = is partly=20 due to the fact that there are twists and turns that the exhaust has = to=20 negotiate, which reduces the speed, and eliminates the supersonic=20 pulses. 
 
As it turns = out, my=20 primary pipes will have to make three 90 degree turns before they get = to the=20 collector.  I've started wondering if these three turns are = enough to=20 reduce the noise to an acceptable level.  My gut feeling = is that it=20 won't be enough, but I think some people are already = running=20 with little to no muffling.  I sure would like to eliminate = that=20 muffler, but I'm not optimistic that it will be possible.  What = do you=20 think?  Silly idea?
 
Cheers,
Rusty
  
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