X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1020598 for flyrotary@lancaironline.net; Fri, 24 Jun 2005 15:19:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; 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-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5OJIaY5015318 for ; Fri, 24 Jun 2005 15:18:37 -0400 (EDT) Message-ID: <003e01c578f1$86a7ea10$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Date: Fri, 24 Jun 2005 15:18:38 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003B_01C578CF.FF5F82A0" 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_003B_01C578CF.FF5F82A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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 ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Friday, June 24, 2005 1:44 PM Subject: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause supported by the fact that I had notice my coolant pressure = increasing on the flight to Charlies by approx 11/2 psi per hour of = flight. It started at a normal 10 psi and had increased to18 psi by the = end of the flight. =20 Ed, this paragraph caught my attention. I've been seeing high coolant = pressures lately and am wondering what is normal. In two or three hours = of ground running and one flight I've noticed that the coolant pressure = climbs fairly quickly to around 25PSI or even a little more, and seem to = be throttle dependant. I have a 24psi cap, but never see it release any = fluid. During the flight I checked while airborne and saw about 10 PSI = each time I looked. I haven't lost any coolant or oil.=20 Regards John ------=_NextPart_000_003B_01C578CF.FF5F82A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi John,
 
A couple of things.  Tracy and I both = discovered that=20 one 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 it to=20 build to that point.  At first, I thought "coolant Leak", however, = I could=20 never find any evidence of coolant in the chambers nor loss of coolant = in the=20 system.  Talking to Tracy Crook, he reported the same thing.  = We came=20 to the conclusion that without a small cushion of air that the pressure = sensor=20 was seeing hydraulic pressure caused by the pump.  With no air = cushion even=20 a small disturbance would likely cause the pressure sensor to indicate = high=20 pressure. As the block and components heated up the coolant volume = got a=20 tiny bit larger due to expansion of parts and the hydraulic = pressure=20 quickly decreased.   At least = that was=20 the best theory we could come up with at the time.
 
 During flight the pressure would quickly = decrease=20 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=20 coolant pressure never got above 12 psi (right after take off when = hottest) and=20 most of the time ran at 8 psi.   So if you are seeing a = nominal=20 10 psi and only seeing the 25 psi on startup, I don't think you have any = problem=20 especially if no evidence of coolant in exhaust stacks.  =
 
Ed A
----- Original Message -----
From:=20 John=20 Slade
Sent: Friday, June 24, 2005 = 1:44 PM
Subject: [FlyRotary] Re: Engine = Rebuild -=20 Coolant Leak Cause

 supported by the fact that I had notice = my coolant=20 pressure increasing on the flight to Charlies by approx 11/2 psi per = hour of=20 flight. It started at a normal 10 psi and had increased to18 psi by = the end of=20 the flight.   
 
Ed, this paragraph caught my attention. = I've been=20 seeing high coolant pressures lately and am wondering what is normal. = In two=20 or three hours of ground running and one flight I've noticed that the = coolant=20 pressure climbs fairly quickly to around 25PSI or even a little more, = and seem=20 to be throttle dependant. I have a 24psi cap, but never see it release = any=20 fluid. During the flight I checked while airborne and saw about 10 PSI = each=20 time I looked. I haven't lost any coolant or oil.=20
Regards
John =
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