X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ew0-f52.google.com ([209.85.215.52] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4587145 for flyrotary@lancaironline.net; Sun, 21 Nov 2010 10:31:26 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.52; envelope-from=msteitle@gmail.com Received: by ewy4 with SMTP id 4so3792478ewy.25 for ; Sun, 21 Nov 2010 07:30:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=+HuUCe0ElqIsVTkTDNaf41qm8sLU7zhikVPF5qxzdRQ=; b=vFny5aCjw6wYQtp/pnsOHbJxar7PyCMwNh2BACKK/NtikAyT8Axu2i5J2f/WWWEwdV snyoQ1yUzBSrhcOKyU0bPOpykt5In9+iFc8o1d1jKJMISAD7kYr7XiPDzpvBk+/s0HdX 3MUZ3JpcX+XGtcvDRQaGY7izESjDp8sRFPBmU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=WBFL9w4R/neV1Mml7DtYcBn8WodwzwLmkDzKR343Ylcc+tni22M7wAf0g9Nodkzg5D tG9/xcCsxHk7ktiKeI3fAs+2hv9nsgIfog8q8UDf93YOCY0g8dB5SJOZRd5IOkBfte2l iw2SfBty9Nq53F8TwsjyIMSt5rSVU3AG1j55s= MIME-Version: 1.0 Received: by 10.213.16.72 with SMTP id n8mr6632733eba.38.1290353451032; Sun, 21 Nov 2010 07:30:51 -0800 (PST) Received: by 10.213.36.17 with HTTP; Sun, 21 Nov 2010 07:30:50 -0800 (PST) In-Reply-To: References: Date: Sun, 21 Nov 2010 09:30:50 -0600 Message-ID: Subject: Re: [FlyRotary] Modified header Calculations From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174c3fce156001049591d341 --0015174c3fce156001049591d341 Content-Type: text/plain; charset=ISO-8859-1 Ed, Now I've got you doing it. I have always been suspicious of applying formulas to the rotary that were derived from 4-stroke piston engines. The fact that the rotary book suggests exhaust tube lengths of between 10 and 18" confirms my suspicions. Also, a 15" tube should be much easier to fit under the cowl. There may even be room for a muffler if I plan carefully. I appreciate you putting the spreadsheet together so us non-engineering types can understand this stuff. Mark On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson wrote: > Mark, > > I did some additional reading in the rotary book I recommended to you and a > bit more head scratching on exhaust systems. > > I modified the tube length formula I used earlier to compensate for the > fact the rotary puts out two exhaust pulses per port per 720 deg cycle > compared to 1 for the piston engine. This in effect halved the length of > tube needed to get the same scavenging effect. > > Also using the recommended rotary book values for area of a rotary exhaust > tube , I calculated the tube diameter which came out to 1.8". > > In any case, I have attached the spreadsheet with those modifications > > Ed > > > Edward L. Anderson > Anderson Electronic Enterprises LLC > 305 Reefton Road > Weddington, NC 28104 > http://www.andersonee.com > http://www.eicommander.com > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --0015174c3fce156001049591d341 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Ed,=A0

Now I've got you doing it. =A0I have always b= een suspicious of applying formulas to the rotary that were derived from 4-= stroke piston engines. =A0The fact that the rotary book suggests exhaust tu= be lengths of between 10 and 18" confirms my suspicions. =A0Also, a 15= " tube should be much easier to fit under the cowl. =A0There may even = be room for a muffler if I plan carefully. =A0I appreciate you putting the = spreadsheet together so us non-engineering types can understand this stuff.=

Mark



On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson &l= t;eanderson@carolina.rr.com> wrote:
Mark,
=A0
I did some additional reading in the rotary book = I=20 recommended to you and a bit more head scratching on exhaust=20 systems.
=A0
--
Homepage: =A0http:/= /www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancaironline.net:81/lists= /flyrotary/List.html


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