X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m15.nyc.untd.com ([64.136.22.78] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with SMTP id 932402 for flyrotary@lancaironline.net; Wed, 04 May 2005 13:09:59 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.22.78; envelope-from=jbker@juno.com Received: from m15.nyc.untd.com (localhost [127.0.0.1]) by m15.nyc.untd.com with SMTP id AABBHUAN3A58GU92 for (sender ); Wed, 4 May 2005 10:08:41 -0700 (PDT) X-UNTD-OriginStamp: Y+Mfppm2QyGfnY/dq+iW1bX7VodxyobaL+v/eg5f8tORCNPcpX2m/A== Received: (from jbker@juno.com) by m15.nyc.untd.com (jqueuemail) id KR6ZWJWS; Wed, 04 May 2005 10:07:58 PDT To: flyrotary@lancaironline.net Date: Wed, 4 May 2005 13:05:19 -0400 Subject: Re: [FlyRotary] Re: EGT temps Message-ID: <20050504.130519.2832.4.JBKER@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_6095.7554.766c X-Juno-Line-Breaks: 8-6,7-8,14-15,17-19,22-23,27-28,29-32767 From: WALTER B KERR X-ContentStamp: 10:5:2447838861 This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ----__JNP_000_6095.7554.766c Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit David C wrote: A point I like to think of is that 50 or 80 degrees "from" "peak" on the rich side and on the lean side is, the same temperature. For piston engines, running 50 deg lean of peak is the same temp as running 50 deg rich of peak, so the valves are seeing the same temp - so why are some engine "gurus" so adament about cruising 50 deg rich of peak? It makes no sense to me. So, I believe there is no such thing as "EGT too high". There is only "peak EGT", whatever it is for your installation. ----------------------------------------------------------------- I ran EGT indicated over 1750 which is where Tracy had the EM2 high limit set. When I told Tracy this, he was not concerned and said set the limit to 1850. The reason folks do not want you running within 50 degrees of peak on piston engines that many only have one EGT and the distribution among cylinders is usually >50 degrees and therefore do not want you running near peak, either over or under since there may well be a hot one. Bernie ----__JNP_000_6095.7554.766c Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable
David C wrote:
 
A point I like to think of is that 50 or = 80 degrees=20 "from" "peak" on the rich side and on the lean side is, the same=20 temperature.  For piston engines, running 50 deg lean of peak is the = same=20 temp as running 50 deg rich of peak, so the valves are seeing the same temp= - so=20 why are some engine "gurus" so adament about cruising 50 deg rich= of=20 peak?  It makes no sense to me.
 
So, I believe there is no such thing as "= EGT too=20 high".  There is only "peak EGT", whatever it is for  your=20 installation.
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I ran EGT indicated over 1750 which is = where Tracy=20 had the EM2 high limit set. When I told Tracy this, he was not concerned = and=20 said set the limit to 1850.
 
The reason folks do not want you running = within 50=20 degrees of peak on piston engines that many only have one EGT and the=20 distribution among cylinders is usually >50 degrees and therefore do not= want=20 you running near peak, either over or under since there may well be a hot=20 one.
 
Bernie
 
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