X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1.6) with ESMTP id 1852286 for flyrotary@lancaironline.net; Tue, 20 Feb 2007 21:43:22 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id l1L1wHTp024402 for ; Tue, 20 Feb 2007 20:58:17 -0500 (EST) Message-ID: <001701c7555b$ca24e930$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Another exploding cigar?? Date: Tue, 20 Feb 2007 20:58:31 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C75531.E0F92010" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C75531.E0F92010 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi John, I originally, had an 18" length of tubing that I had drilled 1/8" holes = in (a really tedious task) along its length and around its = circumference. I initially thought it really didn't help, until on = start up and taxi while at Tracy's one visit - one of them fell off my = header. Tracy immediately detected the difference in volume and saw = what had happened. waved me down and I put it back on more securely. So the answer is it will undoubtedly help some - but, it will still be = loud. The best you can hope from is to drop it from ear shattering to = just very loud. Without some sort of damping on a turbo block the = exhaust pegs a 125 dB digital sound meter. If you have an N/A block then that helps about 8 db worth right there. = If you have a turbocharger then you would be in great shape. You may get a bit more muffling than I did as you appear to have both = exhaust ports going to one tube instead of two like I do. Surprisingly = it turns out (according to what I have read on exhausts) its easier to = dampen the sound with the two pipes into one than each by itself. I am really interested as I have tried about 5 different approaches. = Those that dampen the sound don't live long and vice versa. Ed ----- Original Message -----=20 From: John Downing=20 To: Rotary motors in aircraft=20 Sent: Tuesday, February 20, 2007 7:45 PM Subject: [FlyRotary] Another exploding cigar?? Ed, here are the pictures of the exploding cigar I'm working on = (experimental,right), the pipe is 2 1/2", the same as my exhaust. The = perforated screen has 5/32" holes and is installed in a 5" long cut = which is about 27 degrees from the horizontal of the pipe. If the noise = level is lowered by this installation I will find some SS of about .060" = and weld up one of all SS. This is all regular exhaust pipe for trial = and not intended for flight, although it is 30 inches from the rotors = and could be ok? Startup is still about 3 weeks away, as the intake = manifold is still at the welders. I welcome any and all comments and = criticism, as I stated, I don't have a clue how this will work. JohnD -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0014_01C75531.E0F92010 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi John,
 
I originally, had an 18" length of tubing that I = had=20 drilled 1/8" holes in (a really tedious task) along its length and = around its=20 circumference.  I initially thought it really didn't help, until on = start=20 up and taxi while at Tracy's one visit - one of them fell off my = header. =20 Tracy immediately detected the difference in volume and saw what had = happened.=20 waved me down and I put it back on more securely.
 
So the answer is it will undoubtedly help some - = but, it=20 will still be loud.  The best you can hope from is to drop it from = ear=20 shattering to just very loud.  Without some sort of damping on a = turbo=20 block the exhaust pegs a 125 dB digital sound meter.
 
If you have an N/A block then that helps about 8 = db worth=20 right there.  If you have a turbocharger then you would be in great = shape.
 
You may get a bit more muffling than I did as = you appear=20 to have both exhaust ports going to one tube instead of two like I = do. =20 Surprisingly it turns out (according to what I have read on exhausts) = its easier=20 to dampen the sound with the two pipes into one than each by=20 itself.
 
I am really interested as I have tried about 5 = different=20 approaches.  Those that dampen the sound don't live long and vice=20 versa.
 
Ed
----- Original Message -----
From:=20 John=20 Downing
Sent: Tuesday, February 20, = 2007 7:45=20 PM
Subject: [FlyRotary] Another = exploding=20 cigar??

Ed, here are the pictures of the = exploding cigar=20 I'm working on (experimental,right), the pipe is 2 1/2", the same as = my=20 exhaust.  The perforated screen has 5/32" holes and is installed = in=20 a 5" long cut which is about 27 degrees from the horizontal of = the=20 pipe.  If the noise level is lowered by this installation I will = find=20 some SS of about .060" and weld up one of all SS.  This is all = regular=20 exhaust pipe for trial and not intended for flight, although it is 30 = inches=20 from the rotors and could be ok?  Startup is still about 3 weeks = away, as=20 the intake manifold is still at the welders.  I welcome any and = all=20 comments and criticism, as I stated, I don't have a clue how this will = work.  JohnD

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Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 http://mail.lancaironline.net/lists/flyrotary/
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