X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2877382 for flyrotary@lancaironline.net; Tue, 29 Apr 2008 15:49:49 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080429194908.ONUG3568.fed1rmmtao106.cox.net@fed1rmimpo02.cox.net> for ; Tue, 29 Apr 2008 15:49:08 -0400 Received: from BigAl ([72.192.137.74]) by fed1rmimpo02.cox.net with bizsmtp id KXp91Z0081cVYgg04Xp9cB; Tue, 29 Apr 2008 15:49:09 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Cooling sytem changes- Velocity 20B Date: Tue, 29 Apr 2008 11:53:17 -0800 Message-ID: <000001c8aa32$ab7027c0$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C8A9EF.9D4CE7C0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C8A9EF.9D4CE7C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, For max power lower temps are fine. Most people find max power at = around 175=B0F. Best efficiency is usually at slightly higher temp, around = 190=B0F. With the modern need for higher gas milage most manufacturers are going = to 190=B0 thermostats. Having a too low temperature is something of a = luxury though! Bill Jepson Bill; Your last sentence is certainly true. I put the 170F thermostat in-line with the second rad to keep the temp above that; thinking the one = radiator in the cowl would not cool too much considering the added heat load from = the oil/water cooler. I drilled three 5/32=94 holes in the thermostat to = keep some flow going through not thinking that would provide any significant cooling, but I guess it does. First step is to replace the thermostat; = then see if it might be appropriate to reduce the airflow into the in-cowl = rad =96 in some way that reduces drag. But the nice thing is there is no = urgency =96 and my flight regime is not limited. =20 Al =20 ------=_NextPart_000_0001_01C8A9EF.9D4CE7C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Al, For max power lower temps are fine. Most = people find max power at around 175=B0F. Best efficiency is usually at slightly = higher temp, around 190=B0F. With the modern need for higher gas milage most manufacturers are going to 190=B0 thermostats. Having a too low = temperature is something of a luxury though!
Bill Jepson

Bill;

Your last sentence is certainly = true.=A0 I put the 170F thermostat in-line with the second rad to keep the temp = above that; thinking the one radiator in the cowl would not cool too much = considering the added heat load from the oil/water cooler.=A0 I drilled three = 5/32” holes in the thermostat to keep some flow going through not thinking = that would provide any significant cooling, but I guess it does. =A0First step is = to replace the thermostat; then see if it might be appropriate to reduce the = airflow into the in-cowl rad – in some way that reduces drag.=A0 But the nice = thing is there is no urgency – and my flight regime is not = limited.

 

Al

=A0

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