X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtprh01.spirittelecom.com ([165.166.0.77] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTPS id 2211427 for flyrotary@lancaironline.net; Sun, 29 Jul 2007 10:41:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=165.166.0.77; envelope-from=jewen@comporium.net X-Report-Abuse-To: abuse@spirittelecom.com Received: from engineer1 (165-166-183-191.lnhe.2wcm.comporium.net [165.166.183.191] (may be forged)) by smtprh01.spirittelecom.com (8.13.6/8.13.1) with SMTP id l6TEfDoV028348 for ; Sun, 29 Jul 2007 14:41:16 GMT Message-ID: <00bd01c7d1ee$80620e80$6405a8c0@cooleygroup.local> From: "Joe Ewen" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Individual Exhaust Date: Sun, 29 Jul 2007 10:41:08 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00BA_01C7D1CC.F8CFCCD0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Virus-Scanned: ClamAV 0.88/3804/Sun Jul 29 04:09:31 2007 on smtprh01.spirittelecom.com X-Virus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_00BA_01C7D1CC.F8CFCCD0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Does this solem length information apply to a 20B. I would also assume = that "(two pipes with a muffler on each)" would read 'three pipes with a = muffler on each' when using a 20B.' Joe ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 28, 2007 2:43 PM Subject: [FlyRotary] Re: Individual Exhaust In a message dated 7/28/2007 10:10:17 A.M. Eastern Daylight Time, = eanderson@carolina.rr.com writes: The benefit of mutual scavenging is that the length of tubing to = make that=20 happen is shorter (by approx 1/2) than the self scavenging approach. = The=20 reason is there is approx 120 rotor degrees between two exhaust port = openings on one rotor, whereas there is only approx 60 deg rotor = degrees=20 between port opens between the two rotors permitting a shorter tube = to get=20 the timing right which is rpm dependent as well as exhaust gas temp=20 dependent. FWIW Ed Let us open our Rotary Bibles, (Racing Beat Catalog) to Psalm (page) = 23 and read: For non-ported, street ported, or Bridge ported engines. Short system = is 22 to 25 inches, Long system is 120 to 125 inches of tubing 1.7 to = 1.8 ID. For 600 to 650 Holleys, short system is 15 to 18 inches. The long = system is 113 to 118 inches. For Pport engines the short system is 10 to 18 inches and the long = system is 89 to 94 inches with tubing ID of 1.9 to 2.0 inches.=20 I suggest that these numbers are measurements from actual successful = race cars. The lengths for the long systems must include mufflers of = some sort with exhaust ending beyond the rear bumper.=20 Typical systems had the collector and Mazda race muffler under the = rear bumper. So, probably, single pipes from each housing might work fine. (two = pipes with a muffler on each) And might work fine in much shorter = lengths. Scavenge wise. Un-muffled is out of the question. Lynn E. Hanover =20 -------------------------------------------------------------------------= ----- Get a sneak peek of the all-new AOL.com. ------=_NextPart_000_00BA_01C7D1CC.F8CFCCD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Does this solem length information apply to a 20B. I would = also assume=20 that "(two pipes with a muffler on each)" would read 'three pipes = with a=20 muffler on each'  when using a 20B.'
 
Joe
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Saturday, July 28, 2007 = 2:43=20 PM
Subject: [FlyRotary] Re: = Individual=20 Exhaust

In a message dated 7/28/2007 10:10:17 A.M. Eastern Daylight Time, = eanderson@carolina.rr.com=20 writes:
The=20 benefit of mutual scavenging is that the length of tubing to make = that=20
happen is shorter (by approx 1/2) than the self scavenging=20 approach.  The
reason is there is approx 120 rotor degrees = between=20 two exhaust port
openings on one rotor, whereas there is only = approx 60=20 deg rotor degrees
between port opens between the two rotors = permitting a=20 shorter tube to get
the timing right which is rpm dependent as = well as=20 exhaust gas temp=20
dependent.

FWIW

Ed
 
Let us open our Rotary Bibles, (Racing Beat Catalog) to Psalm = (page) 23=20 and read:
 
For non-ported, street ported, or Bridge ported engines. Short = system is=20 22 to 25 inches, Long system is 120 to 125 inches of tubing 1.7 to 1.8 = ID.
 
For 600 to 650 Holleys, short system is 15 to 18 inches. The long = system=20 is 113 to 118 inches.
 
For Pport engines the short system is 10 to 18 inches and the = long system=20 is 89 to 94 inches with tubing ID of 1.9 to 2.0 inches.
 
I suggest that these numbers are measurements from actual = successful=20 race cars. The lengths for the long systems must include mufflers of = some sort=20 with exhaust ending beyond the rear bumper.
 
Typical systems had the collector and Mazda race muffler under = the rear=20 bumper.
 
So, probably, single pipes from each housing might work fine. = (two pipes=20 with a muffler on each) And might work fine in much shorter lengths. = Scavenge=20 wise. Un-muffled is out of the question.
 
Lynn E. Hanover    



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