X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m12.lax.untd.com ([64.136.30.75] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with SMTP id 1022626 for flyrotary@lancaironline.net; Sun, 26 Jun 2005 22:19:09 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com Received: from m12.lax.untd.com (localhost [127.0.0.1]) by m12.lax.untd.com with SMTP id AABBM82QFACLMZM2 for (sender ); Sun, 26 Jun 2005 19:17:41 -0700 (PDT) X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkA9IOHDdiPlK/Co3RqxZ1HfoATV0uPuc7Q== Received: (from alwick@juno.com) by m12.lax.untd.com (jqueuemail) id KWGGDJYU; Sun, 26 Jun 2005 19:16:47 PDT To: flyrotary@lancaironline.net Date: Sun, 26 Jun 2005 19:16:28 -0700 Subject: Re: [FlyRotary] Re: Coolant Leak Message-ID: <20050626.191632.1028.2.alwick@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_0dcf.4f02.5e93 X-Juno-Line-Breaks: 8-6,7,14-15,20-36,38-39,47-130,131-32767 From: al p wick X-ContentStamp: 6:3:4194146543 X-MAIL-INFO: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 e500791d212d393c4df90141398d61411d X-UNTD-Peer-Info: 127.0.0.1|localhost|m12.lax.untd.com|alwick@juno.com 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. ----__JNP_000_0dcf.4f02.5e93 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I'm sorry Georges, I don't understand your statement. All auto cooling sys I'm familiar with have rad cap on top of radiator. They are designed to have no air in the cooling system. Shortly after you start up the car, coolant flows from cap 14psi valve to overflow bottle. This pressure increase is entirely due to coolant expansion due to heat. When you shut car off, the pressure drop in the radiator draws in coolant from cap 1 psi valve connected to overflow bottle back into the radiator. Thus the radiator is always full to top. I'm recommending cup of air in the active cooling system, not the overflow reservoir. This is different than any modern vehicle I know of. The purpose is to allow you to use psi as indication of how safe you are from boil over and other faults. With cup-o-air, your system will very gradually increase pressure as temperature increases. Check out this site. I often do. http://auto.howstuffworks.com/cooling-system.htm -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Sun, 26 Jun 2005 18:23:02 -0700 (Pacific Standard Time) "Echo Lake Fishing Resort (Georges Boucher)" writes: Al In a car if you have a header tank (expansion bottle) with a pressure cap on the bottle & not on the rad the air space will be in the bottle, if you have system with the pressure cap on the rad & no pressure cap on the bottle the air space will be in the rad. All systems in one way or an other need coolant expansion room somewhere. BTW for the theory that the coolant"vaporizes" when you first start your engine, try propylene glycol (boils at 360 deg without a pressure cap) if you are right the "Vaporizing will stop, If..... Georges B. -------Original Message------- From: Rotary motors in aircraft Date: 06/26/05 17:20:04 To: Rotary motors in aircraft Subject: [FlyRotary] Re: Coolant Leak Actually, I think the opposite is true. I understand the auto approach is to NOT have any air in the cooling system. I don't recall the details of their reasoning. In my experience, the safety advantage of cup-o-air is much more significant. BTW, it's probably more like 2 cups. The goal is to have enough air cushion to prevent pressure from reaching cap rating. When you include coolant temp, fluid level, and pressure info, it really improves your understanding of how your system is behaving. If you ever open your car radiator and find air at top, it indicates a problem with your cooling system. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Sun, 26 Jun 2005 13:15:14 -0400 "Ian Dewhirst" writes: > Al, your experience with the value of having an air cushion is > supported by > every automotive cooling system that I have ever seen (many). > Typically > autos use either a pressure cap and expansion tank that is not > filled to the > top, or an overflow bottle into which coolant is expelled and > recovered. I > get the impression that some people assume that these overflow style > systems > contain no vapour when cold, I don't think that assumption is > correct. The > overflow systems all have expansion capacity built into the top of > the > radiator, or some other part of the cooling system they are never > completely > filled with coolant. The bigger the cooling system the greater the > volume > of vapour stored cold. > > -- Ian > > (GM, Chrysler, and Ford are not trying to piss you off with those > side > mounted radiator caps.. ;-) > > > > > -----Original Message----- > From: Rotary motors in aircraft > [mailto:flyrotary@lancaironline.net]On > Behalf Of al p wick > Sent: Sunday, June 26, 2005 11:58 AM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: Coolant Leak > > > My focus is on flight safety. I found great value to having appx. 1 > cup > of air at the top of my cooling system.... > > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html > > >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ----__JNP_000_0dcf.4f02.5e93 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable
I'm sorry Georges, I don't understand your statement.
All auto cooling sys I'm familiar with have rad cap on top of radiator= .=20 They are designed to have no air in the cooling system. Shortly=20 after you start up the car, coolant flows from cap 14psi valve to= =20 overflow bottle. This pressure increase is entirely due to coolant = expansion due=20 to heat. When you shut car off, the pressure drop in the radiator draws in= =20 coolant from cap 1 psi valve connected to  overflow bottle back = into=20 the radiator. Thus the radiator is always full to top.
 
I'm recommending cup of air in the active cooling system, not the = overflow=20 reservoir. This is different than any modern vehicle I know of. The purpose= is=20 to allow you to use psi as indication of how safe you are from boil over = and=20 other faults. With cup-o-air, your system will very gradually increase = pressure=20 as temperature increases.
 
Check out this site. I often do.
 
http://auto.= howstuffworks.com/cooling-system.htm
 
 
 
 

-al wick
Artificial intelligence in cockpit, Cozy IV powered by= =20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland,=20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
 
On Sun, 26 Jun 2005 18:23:02 -0700 (Pacific Standard Time) "Echo Lake= =20 Fishing Resort (Georges Boucher)" <echolakeresort@telus.net>=20 writes:
Al
In a car if you have a header tank (expansion bottle) = with a=20 pressure cap on the bottle & not on the rad the air space will = be in=20 the bottle, if you have system with the pressure cap on the rad &= amp; no=20 pressure cap on the bottle the air space will be in the rad. All = systems=20 in one way or an other need coolant expansion room somewhere. BTW = for=20 the theory that the coolant"vaporizes" when you first start your = engine,=20 try propylene glycol (boils at 360 deg without a  = pressure=20 cap) if you are right the "Vaporizing will stop, If.....
Georges B.
 
-------Original=20 Message-------
 
From: Rotary motors in=20 aircraft
Date: 06/26/= 05=20 17:20:04
To: Rotary motors in=20 aircraft
Subject: [= FlyRotary]=20 Re: Coolant Leak
 
Actually, I think the opposite is true. I understand the auto= =20 approach is
to NOT have any air in the cooling system. I don't recall the= =20 details of
their reasoning. In my experience, the safety advantage of=20 cup-o-air is
much more significant.
BTW, it's probably more like 2 cups. The goal is to have = enough=20 air
cushion to prevent pressure from reaching cap rating. When you= =20 include
coolant temp, fluid level, and pressure info, it really = improves=20 your
understanding of how your system is behaving.
 
If you ever open your car radiator and find air at top, it=20 indicates a
problem with your cooling system.
 
 
 
-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock = Subaru=20 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
 
 
 
On Sun, 26 Jun 2005 13:15:14 -0400 "Ian Dewhirst" <ianddsl@magma.ca>
writes:
> Al, your experience with the value of having an air = cushion=20 is
> supported by
> every automotive cooling system that I have ever seen=20 (many).
> Typically
> autos use either a pressure cap and expansion tank that = is=20 not
> filled to the
> top, or an overflow bottle into which coolant is expelled= =20 and
> recovered.  I
> get the impression that some people assume that these = overflow=20 style
> systems
> contain no vapour when cold, I don't think that = assumption=20 is
> correct.  The
> overflow systems all have expansion capacity built into = the=20 top of
> the
> radiator, or some other part of the cooling system they = are=20 never
> completely
> filled with coolant.  The bigger the cooling = system=20 the greater the
> volume
> of vapour stored cold.
>
> -- Ian
>
> (GM, Chrysler, and Ford are not trying to piss you off = with=20 those
> side
> mounted radiator caps.. ;-)
>
>
>
>
> -----Original Message-----
> From: Rotary motors in aircraft
> [mailto:flyrotary@= lancaironline.net]On
> Behalf Of al p wick
> Sent: Sunday, June 26, 2005 11:58 AM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Coolant Leak
>
>
> My focus is on flight safety. I found great value to = having=20 appx. 1
> cup
> of air at the top of my cooling system....
>
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://= lancaironline.net/lists/flyrotary/List.html
>
>
 
>>  Homepage:  http://www.flyrotary.com/
>>  Archive:   http://= lancaironline.net/lists/flyrotary/List.html
 
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