X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-da03.mx.aol.com ([205.188.105.145] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5566839 for flyrotary@lancaironline.net; Tue, 29 May 2012 18:24:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.145; envelope-from=Lehanover@aol.com Received: from mtaomg-mb04.r1000.mx.aol.com (mtaomg-mb04.r1000.mx.aol.com [172.29.41.75]) by imr-da03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q4TMNhvh002971 for ; Tue, 29 May 2012 18:23:43 -0400 Received: from core-mod004a.r1000.mail.aol.com (core-mod004.r1000.mail.aol.com [172.29.196.13]) by mtaomg-mb04.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 6082EE00008E for ; Tue, 29 May 2012 18:23:42 -0400 (EDT) From: Lehanover@aol.com Message-ID: <1eb59.29861739.3cf6a66d@aol.com> Date: Tue, 29 May 2012 18:23:42 -0400 (EDT) Subject: Re: [FlyRotary] Re: Exhaust temp To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1eb59.29861739.3cf6a66d_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [173.88.30.23] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1338330222; bh=IM42mlcwPMd1e+Yx2+hWFHEsEhoyOI4ZD8raObMlv9Q=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=DVYm7RoGi5eQY9l05fb/vcYHsiwiBq9JMoE1fgYvL9jOEgj8vzXGSOkFdpIEQ1Zlt op+p0WPZI20W2TK82YHfej1onmadN789rRFi2TL3poDTMBX0/GfMUPRl6UkUCT6L9Q xmzxtb9dKzDJdfEmzCxxbj5yHfwPRP0Q5maDjUPo= X-AOL-SCOLL-SCORE: 0:2:468443296:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294b4fc54c6e59c9 --part1_1eb59.29861739.3cf6a66d_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sounds like you've got it covered.........so to speak. Just to review: Primaries the exact ID of the exhaust liners and exactly the same length to the collector. If you cannot match the ID exactly then make the primaries just a hair bigger. Collect at a shallow angle. (longer collector) Broader torque band. Steeper angle (shorter collector) more torque but narrow band. Collector outlet 2 1/4" to 2 1/2" into a long megaphone to tail pipe size. Try to split the included angles into the collector. A 3" pipe is fine but not for leaving the collector. The tuned length will end there otherwise. Just take a long dart out of the pipe and end the collector with a 2 1/2" ID. Unequal header lengths and or entry angles make a very sad sounding engine. Ideal shapes and angles make for a sweet sounding engine. Loud but sweet. Lynn E. Hanover In a message dated 5/29/2012 2:14:09 P.M. Eastern Daylight Time, echristley@att.net writes: My exhaust is encased in a .015 stainless box down to the end of the collector. The down pipe and muffler are exposed, and I see where it is blistering the belly paint already. I'll be wrapping more of the exhaust in the thin stainless. I will also open the stainless box up to allow some blast air through. First I have to change that down pipe from 1.5" dia to 3". I can't seem to get above 5100RPM, and I think exhaust backpressure is my issue. --part1_1eb59.29861739.3cf6a66d_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Sounds like you've got it covered.........so to speak.

Just to review:

Primaries the exact ID of the exhaust liners and exactly the same leng= th to=20 the collector. If you cannot match the ID exactly then make the=20 primaries just a hair bigger. Collect at a shallow angle. (longer=20 collector) Broader torque band. Steeper angle (shorter collector) more torq= ue=20 but narrow band. Collector outlet 2 1/4" to 2 1/2" into a long megaphone to= tail=20 pipe size. Try to split the included angles into the collector.

A 3" pipe is fine but not for leaving the collector. The tuned length = will=20 end there otherwise. Just take a long dart out of the pipe and end the coll= ector=20 with a 2 1/2" ID.

Unequal header lengths and or entry angles make a very sad sounding en= gine.=20 Ideal shapes and angles make for a sweet sounding engine.

Loud but sweet.

Lynn E. Hanover

In a message dated 5/29/2012 2:14:09 P.M. Eastern Daylight Time,=20 echristley@att.net writes:

= My=20 exhaust is encased in a .015 stainless box down to the end of the=20 collector. The down pipe and muffler are exposed,
and I see wher= e it=20 is blistering the belly paint already. I'll be wrapping more of the= =20 exhaust in the thin stainless.
I will also open the stainless box up t= o=20 allow some blast air through. First I have to change that down pipe from= =20 1.5"
dia to 3". I can't seem to get above 5100RPM, and I think= =20 exhaust backpressure is my=20 issue.

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