X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m23.mx.aol.com ([64.12.137.4] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2210269 for flyrotary@lancaironline.net; Sat, 28 Jul 2007 14:43:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.4; envelope-from=Lehanover@aol.com Received: from Lehanover@aol.com by imo-m23.mx.aol.com (mail_out_v38_r9.2.) id q.cc8.1606967b (41809) for ; Sat, 28 Jul 2007 14:43:11 -0400 (EDT) From: Lehanover@aol.com Message-ID: Date: Sat, 28 Jul 2007 14:43:11 EDT Subject: Re: [FlyRotary] Re: Individual Exhaust To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1185648191" X-Mailer: 9.0 Security Edition for Windows sub 5366 X-Spam-Flag: NO -------------------------------1185648191 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit 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 happen is shorter (by approx 1/2) than the self scavenging approach. The 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 between port opens between the two rotors permitting a shorter tube to get the timing right which is rpm dependent as well as exhaust gas temp 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. 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. 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 ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -------------------------------1185648191 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 7/28/2007 10:10:17 A.M. Eastern Daylight Time,=20 eanderson@carolina.rr.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>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 approach.&n= bsp;=20 The
reason is there is approx 120 rotor degrees between two exhaust po= rt=20
openings on one rotor, whereas there is only approx 60 deg rotor degre= es=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=20 read:
 
For non-ported, street ported, or Bridge ported engines. Short system i= s 22=20 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 syste= m is=20 113 to 118 inches.
 
For Pport engines the short system is 10 to 18 inches and the long syst= em=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 successf= ul=20 race cars. The lengths for the long systems must include mufflers of some so= rt=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 pipe= s=20 with a muffler on each) And might work fine in much shorter lengths. Scaveng= e=20 wise. Un-muffled is out of the question.
 
Lynn E. Hanover    



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