X-Virus-Scanned: clean according to Sophos on Logan.com X-PolluStop-Diagnostic: (direct reply)\eX-PolluStop-Score: 0.00\eX-PolluStop: Scanned with Niversoft PolluStop 2.1 RC1, http://www.niversoft.com/pollustop Return-Path: Received: from [65.54.169.57] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c4) with ESMTP id 860690 for flyrotary@lancaironline.net; Thu, 07 Apr 2005 14:37:36 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.169.57; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Thu, 7 Apr 2005 11:36:52 -0700 Message-ID: Received: from 4.174.5.48 by BAY3-DAV27.phx.gbl with DAV; Thu, 07 Apr 2005 18:36:51 +0000 X-Originating-IP: [4.174.5.48] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: rule of thumb and RV-3 sizes- was Cooling Inlet Date: Thu, 7 Apr 2005 14:36:49 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00DF_01C53B7F.3B9E1B70" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MIMEOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Thu, 7 Apr 2005 14:36:49 -0400 X-OriginalArrivalTime: 07 Apr 2005 18:36:52.0039 (UTC) FILETIME=[C4142D70:01C53BA0] This is a multi-part message in MIME format. ------=_NextPart_000_00DF_01C53B7F.3B9E1B70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ----- Original Message -----=20 To: Rotary motors in aircraft=20 Sent: Thursday, April 07, 2005 2:22 PM Subject: [FlyRotary] Re: rule of thumb and RV-3 sizes- was Cooling = Inlet >On Thu, 07 Apr 2005 12:06:29 -0400 Tracy Crook = > wrote. >MessageThis does "sound right" but the few studies I've seen showing = the >exit air temp on air cooled engines was very close to what water = cooled >engines have been. From: echristley=20 This is completely logical if you consider the extremely small surface = area available to transfer heat on the cylinderhead fins compared to the = surface area on even a small radiator. I agree. To take this even further, an *optimized* water cooled = installation will use fewer CFM to cool a given number of BTUs (and have = less drag) than an aircooled engine. The P-51 would probably not been = able to escort bombers all the way to Germany and back if it had an air = cooled engine (all other factors remaining the same). Tracy ------=_NextPart_000_00DF_01C53B7F.3B9E1B70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
----- Original Message -----
To: Rotary motors in = aircraft
Sent: Thursday, April 07, 2005 = 2:22=20 PM
Subject: [FlyRotary] Re: rule = of thumb=20 and RV-3 sizes- was Cooling Inlet

>On Thu, 07 Apr 2005 12:06:29 -0400 Tracy Crook = <lors01@msn.com> = wrote.
>MessageThis=20 does "sound right"  but the few studies I've seen showing=20 the

>exit air temp on air cooled engines was very close to = what=20 water cooled

>engines have been.


From: echristley

This is completely logical if you consider the extremely = small=20 surface area
available to transfer heat on the cylinderhead fins = compared=20 to the surface
area on even a small radiator.


I = agree.  To=20 take this even further, an *optimized* water cooled installation will = use=20 fewer CFM to cool a given number of BTUs (and have less drag) than an=20 aircooled engine.  The P-51 would probably not been able to = escort=20 bombers all the way to Germany and back if it had an air cooled engine = (all=20 other factors remaining the same).
 
Tracy
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