X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail1.ubtanet.com ([65.174.123.181] verified) by logan.com (CommuniGate Pro SMTP 5.0.7) with ESMTP id 967386 for flyrotary@lancaironline.net; Sat, 04 Feb 2006 12:25:13 -0500 Received-SPF: none receiver=logan.com; client-ip=65.174.123.181; envelope-from=archerw@ubtanet.com Received: from archer (unknown [198.70.252.50]) by mail1.ubtanet.com (Postfix) with ESMTP id 363FB1EC675 for ; Sat, 4 Feb 2006 10:24:24 -0700 (MST) From: "Todd Archer" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Mazda mufflers Date: Sat, 4 Feb 2006 10:24:51 -0700 Message-ID: <002c01c629af$eb4d11b0$0400000a@archer> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C62975.3EEE39B0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.2627 In-Reply-To: Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C62975.3EEE39B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I=92ve wondered about the suitability of the Racing Beat presilencers. = I don=92t think it=92s SS wool but wider strips of SS they use to fill it. That=92s the first thing the exhaust sees after the header and I know = they hold up. This is everyday car driving, too. Lynn, do these things hold up at all in race duty cycles? =20 The case is =BC=94 mild steel, I believe, so there would be a weight = penalty off the shelf. Maybe these innards and a SS can. =20 =20 Todd Archer =20 =20 =20 =20 =20 The problem with fillers, or packing if you like is twofold. The usual glass like material used in piston engine mufflers, just melts. If you catch it quickly, you may get to see the glass balls before they are machined away and vanish. =20 If you try a ceramic blanket material like I did, you discover that the hammering of the exhaust pulses mechanically decomposes that material, or any material into fuzz and blows it out.=20 =20 The race car muffler has small tubes with thousands of small perforations. A 4" perforated tube down through the center, with 5 additional smaller perf tubes inside of that tube. Still under 100 dB at 50 feet after 7 years of service. It looks like the Burns mufflers but is very much larger and is about 27 pounds. The Burns mufflers look like the way to go to me. They offer stainless swarf packings which might hold up for quite a while.=20 =20 Years ago, there were mufflers (very big and heavy) used in Mazda race cars that had Lava Rock fillings. There was a bung with a screw in plug so you could refill the lava rock after each race. The Mazda just turns it into dust with the hammering. =20 Lynn E. Hanover=20 ------=_NextPart_000_002D_01C62975.3EEE39B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I’ve wondered about the suitability of the Racing Beat presilencers.=A0 I don’t think it’s SS wool but wider strips of SS they use to fill it.=A0 That’s the first thing the = exhaust sees after the header and I know they hold up.=A0 This is everyday car driving, too.=A0 Lynn, do these things hold up at all in race duty = cycles?

 =

The case is = =BC” mild steel, I believe, so there would be a weight penalty off the shelf. = =A0Maybe these innards and a SS = can.=A0

 =

Todd = Archer

 =

 =

 =

 =

 =

The problem with fillers, or packing if you like = is twofold. The usual glass like material used in piston engine mufflers, = just melts. If you catch it quickly, you may get to see the glass balls = before they are machined away and vanish.

 

If you try a ceramic blanket material like I did, you discover that the = hammering of the exhaust pulses mechanically decomposes that material, or any = material into fuzz and blows it out.

 

The race car muffler has small tubes with thousands of small perforations. A 4" perforated tube down through the center, with 5 additional = smaller perf tubes inside of that tube. Still under 100 dB at 50 feet after 7 = years of service. It looks like the Burns mufflers but is very much larger and is = about 27 pounds. The Burns mufflers look like the way to go to me. They offer stainless swarf packings which might hold up for quite a while. =

 

Years ago, there were mufflers (very big and heavy) used in Mazda race cars = that had Lava Rock fillings. There was a bung with a screw in plug so you could = refill the lava rock after each race. The Mazda just turns it into dust with = the hammering.

 

Lynn E. Hanover 

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