X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1024243 for flyrotary@lancaironline.net; Mon, 27 Jun 2005 22:31:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5S2UHBI023860 for ; Mon, 27 Jun 2005 22:30:23 -0400 (EDT) Message-ID: <005c01c57b89$5857c410$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Date: Mon, 27 Jun 2005 22:30:26 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0059_01C57B67.D1141790" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0059_01C57B67.D1141790 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause ----- Original Message -----=20 From: Bulent Aliev=20 To: Rotary motors in aircraft=20 Sent: Monday, June 27, 2005 11:17 AM Subject: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause On 6/24/05 3:18 PM, "Ed Anderson" wrote: Hi John, 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 find any evidence of coolant in the chambers nor loss of = coolant in the system. 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 was 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 quickly decreased. At = least that was the best theory we could come up with at the time. During flight the pressure would quickly decrease until it was below = 10 psi and on cool days would got to zero. 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 the time ran at 8 psi. So if you are seeing a nominal 10 psi = and only seeing the 25 psi on startup, I don't think you have any = problem especially if no evidence of coolant in exhaust stacks. =20 Ed A Ed, I think that maybe it takes few moments for the pump to accelerate = the mass of coolant inside the cooling system. That's why the pressure = at the pump outlet is high for a while? Buly=20 Could be Buly, although I would think that since liquid is basically = incompressible that it is all accelerated at once. Ed ------=_NextPart_000_0059_01C57B67.D1141790 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak = Cause
 
----- Original Message -----
From:=20 Bulent=20 Aliev
Sent: Monday, June 27, 2005 = 11:17=20 AM
Subject: [FlyRotary] Re: Engine = Rebuild -=20 Coolant Leak Cause

On 6/24/05 3:18 PM, "Ed Anderson" <eanderson@carolina.rr.com&g= t;=20 wrote:
Hi=20 John,

A couple of things.  Tracy and I both discovered = that one=20 ALL the air is out of the coolant system, the coolant pressure may = jump to=20 21 psi almost immediately upon start up - long before the heat would = cause=20 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=20 of coolant in the system.  Talking to Tracy Crook, he reported = the same=20 thing.  We came to the conclusion that without a small cushion = of air=20 that the pressure sensor was seeing hydraulic pressure caused by the = pump.=20  With no air cushion even a small disturbance would likely = cause the=20 pressure sensor to indicate high pressure. As the block and = components=20 heated up the coolant volume got a tiny bit larger due to expansion = of parts=20 and the hydraulic pressure quickly decreased.   At least = that was=20 the best theory we could come up with at the time.

During flight=20 the pressure would quickly decrease until it was below 10 psi and on = cool=20 days would got to zero.

On = my flight=20 back home (some air still in system), the coolant pressure never got = above=20 12 psi (right after take off when hottest) and most of the time ran = at 8=20 psi.   So if you are seeing a nominal 10 psi and only = seeing the=20 25 psi on startup, I don't think you have any problem especially if = no=20 evidence of coolant in exhaust stacks.  

Ed=20 A

Ed,=20 I think that maybe it takes few moments for the pump to accelerate the = mass of=20 coolant inside the cooling system. That=92s why the pressure at the = pump outlet=20 is high for a while?
Buly
 
Could be Buly, although I would think that = since=20 liquid is basically incompressible that it is all accelerated at=20 once.
 
Ed
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