X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf20aec.mail.bellsouth.net ([205.152.59.68] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1023182 for flyrotary@lancaironline.net; Mon, 27 Jun 2005 11:17:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.68; envelope-from=atlasyts@bellsouth.net Received: from ibm62aec.bellsouth.net ([68.213.226.209]) by imf20aec.mail.bellsouth.net with ESMTP id <20050627151708.HVRL1983.imf20aec.mail.bellsouth.net@ibm62aec.bellsouth.net> for ; Mon, 27 Jun 2005 11:17:08 -0400 Received: from [192.168.0.104] (really [68.213.226.209]) by ibm62aec.bellsouth.net with ESMTP id <20050627151708.HZHY8050.ibm62aec.bellsouth.net@[192.168.0.104]> for ; Mon, 27 Jun 2005 11:17:08 -0400 User-Agent: Microsoft-Entourage/11.1.0.040913 Date: Mon, 27 Jun 2005 11:17:04 -0400 Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause From: Bulent Aliev To: Rotary motors in aircraft Message-ID: In-Reply-To: Mime-version: 1.0 Content-type: multipart/alternative; boundary="B_3202715828_298418" > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3202715828_298418 Content-type: text/plain; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable On 6/24/05 3:18 PM, "Ed Anderson" wrote: > Hi John, > =20 > 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= . > Talking to Tracy Crook, he reported the same thing. We came to the concl= usion > 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 press= ure. > As the block and components heated up the coolant volume got a tiny bit l= arger > 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. > =20 > During flight the pressure would quickly decrease until it was below 10 = psi > and on cool days would got to zero. > =20 > On my flight back home (some air still in system), the coolant pressure n= ever > 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 >> =20 Ed, I think that maybe it takes few moments for the pump to accelerate the mass of coolant inside the cooling system. That=B9s why the pressure at the pump outlet is high for a while? Buly --B_3202715828_298418 Content-type: text/html; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause On 6/= 24/05 3:18 PM, "Ed Anderson" <eanderson@carolina.rr.com> wro= te:

Hi John,
A couple of things.  Tracy and I both discov= ered 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 "coola= nt Leak", however, I could never find any evidence of coolant in the ch= ambers nor loss of coolant in the system.  Talking to Tracy Crook, he r= eported the same thing.  We came to the conclusion that without a small= cushion of air that the pressure sensor was seeing hydraulic pressure cause= d by the pump.  With no air cushion even a small disturbance would like= ly cause the pressure sensor to indicate high pressure. As the block and com= ponents 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 decreas= e 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 hot= test) 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.  <= BR>
Ed A

Ed, I think that maybe it takes few momen= ts 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 --B_3202715828_298418--