Return-Path: Received: from [65.54.168.110] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 575490 for flyrotary@lancaironline.net; Tue, 21 Dec 2004 12:00:31 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.110; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 21 Dec 2004 09:00:01 -0800 Message-ID: Received: from 65.54.97.150 by BAY3-DAV6.phx.gbl with DAV; Tue, 21 Dec 2004 16:59:32 +0000 X-Originating-IP: [65.54.97.150] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Oil cooler mount updated pictures Date: Tue, 21 Dec 2004 11:59:28 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_013F_01C4E754.86438EA0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Tue, 21 Dec 2004 11:59:28 -0500 X-OriginalArrivalTime: 21 Dec 2004 17:00:01.0743 (UTC) FILETIME=[82AC1DF0:01C4E77E] This is a multi-part message in MIME format. ------=_NextPart_000_013F_01C4E754.86438EA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageI'll go with Rusty's take on this one. First off, there IS a = pressure bypass in the system (the oil pressure regulator). I see = almost no difference in cold oil pressure than I do with hot oil when = the engine is turning fast enough to be "in regulation". The only = difference is that the regulation point rpm is lower with cold oil.=20 The thermostat does not isolate pressure from the oil cooler anyway = since it is not an oil tight system. Tracy Sing that song to your last cooler again, maybe it will believe. Maybe = not. (I know, tackie sa comment, I apologize.) Too a certain extent, you = are or should be absolutely correct, 5w-30 should be no thicker cold = than 5 and no thinner hot than 30, but, why chance it ? It also = shouldn't have any more pressure, period, than bypass allows but = something obviously causes oil to act differently than water, with = coolers anyway; and, while hydraulic pressure is hydraulic pressure, = fluid density, compressibility difference, whatever, seems to be a good = a guess as any; and, one perhaps easily avoided by thermostatically = controlled relief valve. Why beat the poor little sucker to death = waiting for oil to reach 140, if it does have any effect ? =20 jofarr ----- Original Message ----- From: Russell = Duffy=20 I disagree. I'm using 5W-30, so when it's cold, cold, cold, the oil = still isn't thick, thick, thick :-) Also, airplane guys are kind to = their engines. We crank them, and allow them to gently warm up before = running them hard. This is very different from how it would be used in = the car, which I suspect is why Mazda included the oil thermostat. The = only hassle is waiting for it to get 140 degrees before takeoff. I see = the thermostat as being nice, but not necessary. ------=_NextPart_000_013F_01C4E754.86438EA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message=
I'll go with Rusty's take on this one.  First off, there IS a = pressure=20 bypass in the system (the oil pressure regulator).  I see almost no = difference in cold oil pressure than I do with hot oil when the engine = is=20 turning fast enough to be "in regulation".  The only difference is = that the=20 regulation point rpm is lower with cold oil. 
 
The thermostat does not isolate pressure from the oil cooler anyway = since=20 it is not an oil tight system.
 
Tracy
Sing that song to your last = cooler again,=20 maybe it will believe. Maybe not. (I know, tackie sa comment, I=20 apologize.) Too a certain extent, you are or should be absolutely = correct,=20 5w-30 should be no thicker cold than 5 and no thinner hot than = 30, but,=20 why chance it ? It also shouldn't have any more pressure, period, than = bypass=20 allows but something obviously causes oil to act differently than = water, with=20 coolers anyway; and, while hydraulic pressure is hydraulic = pressure,=20 fluid density, compressibility difference, whatever, seems to be a = good a=20 guess as any; and, one perhaps easily avoided by thermostatically = controlled relief valve.  Why beat the poor little sucker to = death=20 waiting for oil to reach 140, if it does have any effect ?  =
jofarr
----- Original Message ----- = From: Russell=20 Duffy
 
I disagree.  I'm using 5W-30, so = when it's=20 cold, cold, cold, the oil still isn't thick, thick, thick=20 :-)  Also, airplane guys are kind to their engines.  = We crank=20 them, and allow them to gently warm up before running them = hard.  This=20 is very different from how it would be used in the car, which I = suspect is=20 why Mazda included the oil thermostat.  The only hassle is = waiting for=20 it to get 140 degrees before takeoff.  I see the thermostat as = being=20 nice, but not=20 necessary.
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