X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1020932 for flyrotary@lancaironline.net; Fri, 24 Jun 2005 19:39:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; 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-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5ONcPl9028029 for ; Fri, 24 Jun 2005 19:38:26 -0400 (EDT) Message-ID: <001901c57915$d2310830$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Coolant Leak Date: Fri, 24 Jun 2005 19:38:27 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0016_01C578F4.4AEAEAB0" 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_0016_01C578F4.4AEAEAB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, all I can tell you is that the pressure would go immediately = (within 2 seconds) to 21-24 psi. Then as the engine warmed up the = pressure would drop to a nominal 8 psi or so. It seem likely that the = pressure sensor was responding to small variations in the coolant = volume. But, certainly open to another explanation. It was not = coolant/combustion chamber leaks of that much I am certain. Tracy found = the same thing, have not heard any other similar reports until John = Slade mention his coolant pressure build up. Ed ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Friday, June 24, 2005 5:02 PM Subject: [FlyRotary] Coolant Leak A couple of things. Tracy and I both discovered that once 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. =20 Maybe not. How/why would the pump pressurize the system? There = will be some pressure differential across the pump, and downstream from = the pump you will see the drop around the loop; but not 21 psi.=20 Maybe depends on what you mean by "almost immediately". With no air = in the system a small amount of expansion will cause a pressure = increase. I recall seeing over 20 psi when the temp was only up to = 125F. Al ------=_NextPart_000_0016_01C578F4.4AEAEAB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Al, all I can tell you is that the = pressure would go=20 immediately (within   2 seconds) to 21-24 psi.  Then as = the=20 engine warmed up the pressure would drop to a nominal 8 psi or so.  = It seem=20 likely that the pressure sensor was responding to small variations in = the=20 coolant volume.  But, certainly open to another explanation.  = It was=20 not coolant/combustion chamber leaks of that much I am certain.  = Tracy=20 found the same thing, have not heard any other similar reports = until John=20 Slade mention his coolant pressure build up.
 
Ed
 
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Friday, June 24, 2005 = 5:02 PM
Subject: [FlyRotary] Coolant = Leak

 

A couple of = things.  Tracy=20 and I both discovered that once ALL the air is out of the = coolant=20 system, the coolant pressure may jump to 21 psi almost immediately = upon=20 start up - long before the heat would cause it to build to that = point. =20 At first, I thought "coolant Leak", however, I could never find any = evidence=20 of coolant in the chambers nor loss of coolant in the system.  = Talking=20 to Tracy=20 Crook, he=20 reported the same thing.  We came to the conclusion that = without a=20 small cushion of air that the pressure sensor was seeing hydraulic = pressure=20 caused by the pump. 

 

Maybe = not. =20 How/why would the pump pressurize the system?  There will be = some=20 pressure differential across the pump, and downstream from the pump = you will=20 see the drop around the loop; but not 21 psi.

 

Maybe = depends on=20 what you mean by =93almost immediately=94.  With no air in the = system a=20 small amount of expansion will cause a pressure increase.  I = recall=20 seeing over 20 psi when the temp was only up to = 125F.

 

Al

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