Received-SPF: pass
 receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com
To: flyrotary@lancaironline.net
Date: Mon, 27 Jun 2005 03:56:10 -0700
Subject: Re: [FlyRotary] Re: Coolant Leak
Message-ID: <20050627.043353.2556.4.alwick@juno.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
From: al p wick <alwick@juno.com>

Sorry Ian, I was not familiar with those types of cooling systems. I
thought I was deviating from standard practice and that always sends up
warning flag. I didn't want to recommend cup-o-air and ignore the
"deviation". From your reports, it sounds like some mfg's use cup-o-air
and others definitely don't. Thanks for setting me straight.

-al wick


On Mon, 27 Jun 2005 01:20:30 -0400 "Ian Dewhirst" <ianddsl@magma.ca>
writes:
> Al, I am going to bow out of this one. I started out by trying to 
> explain
> why your cup of air was a good idea by telling you that you are not 
> alone in
> that strategy, every auto manufacturer in the world relies on a "cup 
> of
> air", "vapor cushion", "spring", whatever.  You don't think that is 
> the case
> which is fine by me, just keep that cup of air in there ;-)
> 
> I came by my info honestly, from having owned a garage and 
> repairing
> automobiles for a living. I have worked on at least 200 different 
> makes and
> models, I kept my eyes open.  I think George came by his knowledge 
> the same
> way.
> 
> Chers -- Ian
> 
> 
> 
> -----Original Message-----
> From: Rotary motors in aircraft 
> [mailto:flyrotary@lancaironline.net]On
> Behalf Of al p wick
> Sent: Sunday, June 26, 2005 11:57 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Coolant Leak
> 
> 
> If you find any info to support your points, let me know will you? 
> What
> do you mean by "you can't have pressure without a spring"? Why do 
> you
> assume coolant is boiled? Why does coolant pushed out have to result 
> in
> vapor?
> 
> I always thought that pressure always increased in closed systems 
> when
> you heat a fluid. This because the molecules get excited and move 
> farther
> apart. The volume tries to increase, but can't due to sys being 
> closed,
> so pressure must rise.
> 
> Here's another cool site...or hot and cool site.
> 
> http://science.howstuffworks.com/stirling-engine1.htm
> 
> 
> -al wick
> 
> 
> On Sun, 26 Jun 2005 23:21:55 -0400 "Ian Dewhirst" 
> <ianddsl@magma.ca>
> writes:
> > Sorry Al, I think you are incorrect on the no vapor theory.  While 
> it
> > is
> > true that in many big three cooling solutions the level in the
> > overflow
> > reservoir will change as the engine is cycled from cold to hot 
> back
> > to cold
> > again,  the cooling system is never all liquid.  There has to be
> > vapor
> > before you start.  I am sure that we both agree on the following
> > points: An
> > automobile cooling system needs to be pressurized to operate 
> above
> > the
> > boiling point of water.  You can't have pressure without a spring 
> in
> > a
> > closed system.  The spring used is compressed vapor.  If you 
> don't
> > start out
> > with vapor, you will push out coolant until you create some 
> vapor,
> > this
> > vapour is the result of coolant that has boiled in the block
> > somewhere.  A
> > rad cap is a pressure relief device not an accumulator; it is 
> open
> > or
> > closed.  For a spring loaded to opperate as an accumulator you 
> need
> > an
> > unlimited supply of coolant/air/oil/etc. to flow through at a 
> rate
> > high
> > enough that you can create back pressure, much like the spring
> > loaded
> > pressure regulator on an engine lubrication system.
> >
> > Your radiator may look like it is full but the filler neck likely
> > extends
> > down past the top of the tank or it is on the side of in the case 
> of
> > a cross
> > flow radiator, either way the cooling system is not 100% liquid
> > filled.
> >
> > Since we are all building hybrid cooling systems, we need to
> > remember to
> > leave some vapour in the system ( as you are doing ) to make sure
> > that we
> > are operating with a pressurized system "before" we start to 
> expel
> > coolant
> > from the system.
> >
> > George mentioned the fact that a good many vehicles have systems
> > that never
> > vent coolant through the cap unless over heating, I would agree 
> with
> > him
> > that this is the best solution; usually it involves a combination
> > expansion
> > tank / swirl pot and a pressure cap that is vented to the ground.
> > Cheers -
> > Ian
> >
> >
> > -----Original Message-----
> > From: Rotary motors in aircraft
> > [mailto:flyrotary@lancaironline.net]On
> > Behalf Of al p wick
> > Sent: Sunday, June 26, 2005 8:02 PM
> > 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"
> > <ianddsl@magma.ca>
> > 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
> >
> >
> >
> > >>  Homepage:  http://www.flyrotary.com/
> > >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
> >
> >
> 
> 
> -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
> 
> >>  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
> 
> 


-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