X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1024244 for flyrotary@lancaironline.net; Mon, 27 Jun 2005 22:29:22 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; 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-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5S2SYL5020829 for ; Mon, 27 Jun 2005 22:28:35 -0400 (EDT) Message-ID: <005001c57b89$1b46adc0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Coolant Leak Date: Mon, 27 Jun 2005 22:28:44 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004D_01C57B67.93FBD550" 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_004D_01C57B67.93FBD550 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mark, The phenomena which started this thread was the immediate rise in = pressure during initial start up in some installations (mine for = instance) when all air has been removed from the coolant system. Once = my engine warms up the pressure runs around 8 psi and may climb as high = as 10psi if temps are higher than 200F. It is true that higher = pressure delays the temperature that water boils at - but, higher = pressure may also work against your waterpump seal and cause leaks (just = a thought). I personally prefer to run at lower coolant pressures since = my radiator cap has a max of 21-24 psi. I suspect that while a higher = PSI may indeed delay the onset of the coolant boiling - if your engine = is that hot - you will probably have cooked something (like "O" rings = {:>)).=20 Ed ----- Original Message -----=20 From: Mark R Steitle=20 To: Rotary motors in aircraft=20 Sent: Monday, June 27, 2005 10:07 AM Subject: [FlyRotary] Re: Coolant Leak =20 Ed,=20 Not to stir the swirl pot, but I thought that it was decided some time = back that higher pressures were better than lower pressures. The higher = pressures are supposed provide more margin of safety before a boil-over = occurs, permitting a thinner ethylene-glycol solution and enabling the = engine to tolerate higher temps before experiencing catastrophic = boiling. So, I'm wondering where this leaves us. Is it better to run = at low (7-8 psi) pressures, or high (28-30psi) pressures? =20 =20 Mark S.=20 =20 I agree, Al, inquiring minds at least like a plausible hypothesis and = I think the discussion has led to that. Perhaps I'll leave the "cup" of = air, just for peace of mind {:>)=20 Ed ------=_NextPart_000_004D_01C57B67.93FBD550 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Mark,
 
The phenomena which started this thread was the = immediate=20 rise in pressure during initial start up in some installations (mine for = instance) when all air has been removed from the coolant system.  = Once my=20 engine warms up the pressure runs around 8 psi and may climb as high as = 10psi if=20 temps are higher than 200F.   It is true that higher pressure = delays=20 the temperature that water boils at - but, higher pressure may also work = against=20 your waterpump seal and cause leaks (just a thought).  I personally = prefer=20 to run at lower coolant pressures since my radiator cap has a max of = 21-24=20 psi.  I suspect that while a higher PSI may indeed delay the onset = of the=20 coolant boiling - if your engine is that hot - you will probably have = cooked=20 something (like "O" rings {:>)).
 
Ed
----- Original Message -----
From:=20 Mark R Steitle =
Sent: Monday, June 27, 2005 = 10:07=20 AM
Subject: [FlyRotary] Re: = Coolant=20 Leak

 

Ed,=20

Not to stir = the swirl=20 pot, but I thought that it was decided some time back that higher = pressures=20 were better than lower pressures.  The higher pressures are = supposed=20 provide more margin of safety before a boil-over occurs, permitting a = thinner=20 ethylene-glycol solution and enabling the engine to tolerate higher = temps=20 before experiencing catastrophic boiling.  So, I=92m wondering = where this=20 leaves us.  Is it better to run at low (7-8 psi) pressures, or = high=20 (28-30psi) pressures? 

 

Mark S.=20

 


I agree, Al, = inquiring minds=20 at least like a plausible hypothesis and I think the discussion has = led to=20 that.  Perhaps I'll leave the "cup" of air, just for peace of = mind=20 {:>) =

Ed

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