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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-------
Date: 06/26/05
17:20:04
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:
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
> 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....
>
>
>
>
>
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