X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [199.185.220.224] (HELO priv-edtnes40.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1023308 for flyrotary@lancaironline.net; Mon, 27 Jun 2005 11:42:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=199.185.220.224; envelope-from=echolakeresort@telus.net Received: from boucher-oddle24 ([207.194.26.38]) by priv-edtnes40.telusplanet.net (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with SMTP id <20050627154205.HPHY14306.priv-edtnes40.telusplanet.net@boucher-oddle24> for ; Mon, 27 Jun 2005 09:42:05 -0600 MIME-Version: 1.0 Message-Id: <42C01E48.000004.03336@BOUCHER-ODDLE24> Date: Mon, 27 Jun 2005 08:42:00 -0700 (Pacific Standard Time) Content-Type: Multipart/Alternative; boundary="------------Boundary-00=_0A2RBHK0000000000000" X-Mailer: IncrediMail (3001609) From: "Echo Lake Fishing Resort (Georges Boucher)" References: To: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause X-FID: FLAVOR00-NONE-0000-0000-000000000000 X-Priority: 3 --------------Boundary-00=_0A2RBHK0000000000000 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi! Ed=0D Where is you coolant pressure sender in relation to the water pump outle= t?=0D My theory is that the initial pressure has nothing to do with temperature= , the 13b coolant passages are small,(those A/C condensers add to the restriction.) upon startup the water pump is trying to move a immobile wa= ll of coolant , once the coolant returns to the the pump inlet the flow resistance drops so does the pressure.=0D Georges B.-------Original Message-------=0D =0D From: Rotary motors in aircraft=0D Date: 06/27/05 08:18:00=0D To: Rotary motors in aircraft=0D Subject: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause=0D =0D On 6/24/05 3:18 PM, "Ed Anderson" wrote:=0D =0D =0D Hi John,=0D =0D A couple of things. Tracy and I both discovered that one ALL the air is = out of the coolant system, the coolant pressure may jump to 21 psi almost immediately upon start up - long before the heat would cause it to build = to that point. At first, I thought "coolant Leak", however, I could never f= ind any evidence of coolant in the chambers nor loss of coolant in the system= =2E=20 Talking to Tracy Crook, he reported the same thing. We came to the conclusion that without a small cushion of air that the pressure sensor w= as seeing hydraulic pressure caused by the pump. With no air cushion even a small disturbance would likely cause the pressure sensor to indicate high pressure. As the block and components heated up the coolant volume got a tiny bit larger due to expansion of parts and the hydraulic pressure quic= kly decreased. At least that was the best theory we could come up with at t= he time.=0D =0D During flight the pressure would quickly decrease until it was below 10 p= si and on cool days would got to zero.=0D =0D On my flight back home (some air still in system), the coolant pressure never got above 12 psi (right after take off when hottest) and most of th= e time ran at 8 psi. So if you are seeing a nominal 10 psi and only seein= g the 25 psi on startup, I don't think you have any problem especially if n= o evidence of coolant in exhaust stacks. =0D =0D Ed A=0D =0D =0D =0D Ed, I think that maybe it takes few moments for the pump to accelerate th= e mass of coolant inside the cooling system. That=92s why the pressure at t= he pump outlet is high for a while?=0D Buly =0D =20 --------------Boundary-00=_0A2RBHK0000000000000 Content-Type: Text/HTML; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Hi! Ed
 Where is you coolant pressure sender in relation to the water = pump outlet?
My theory is that the initial pressure has nothing to do with temper= ature, the 13b coolant passages are small,(those A/C condensers add to th= e restriction.) upon startup the water pump is trying to move a immobile = wall of coolant , once the coolant returns to the the pump inlet the flow= resistance drops so does the pressure.
Georges B.-------Original Message-------
 
Date: 06/27/05 08:= 18:00
Subject: [FlyRotar= y] Re: Engine Rebuild - Coolant Leak Cause
 
On 6/24/05 3:18 PM, "Ed Anderson" <eanderson@carolina= =2Err.com> wrote:
Hi John,

= A couple of things.  Tracy and I both discovered that one ALL the ai= r is out of the coolant system, the coolant pressure may jump to 21 psi a= lmost immediately upon start up - long before the heat would cause it to = build to that point.  At first, I thought "coolant Leak", however, I= could never find any evidence of coolant in the chambers nor loss of coo= lant in the system.  Talking to Tracy Crook, he reported the same th= ing.  We came to the conclusion that without a small cushion of air = that the pressure sensor was seeing hydraulic pressure caused by the pump= =2E  With no air cushion even a small disturbance would likely cause= the pressure sensor to indicate high pressure. As the block and componen= ts heated up the coolant volume got a tiny bit larger due to expansion of= parts and the hydraulic pressure quickly decreased.   At least= that was the best theory we could come up with at the time.

Duri= ng flight the pressure would quickly decrease until it was below 10 psi a= nd on cool days would got to zero.

On my flight back home (some a= ir still in system), the coolant pressure never got above 12 psi (right a= fter take off when hottest) and most of the time ran at 8 psi.  &nbs= p;So if you are seeing a nominal 10 psi and only seeing the 25 psi on sta= rtup, I don't think you have any problem especially if no evidence of coo= lant in exhaust stacks.  

Ed A

Ed, I think that maybe it takes few mo= ments for the pump to accelerate the mass of coolant inside the cooling s= ystem. That=92s why the pressure at the pump outlet is high for a while?<= BR>Buly=20
 
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