i don't have any i dea what you're talking about, and i don't
think you really understand what's going on either, no offense.
the thermostat in you engine will start to open up at about what
it's rated at to let the coolant flow through the radiator. and
your engine temperature will remain pretty close to the temp at
which your thermostat is rated for. i have a 160° thermostat in
my engine, and on really hot days, it would only get up to about
180° or so. (i installed an autometer temp gage that tells the
temp) if i had a 190° thermostat, i imagine the engine would
run around 200° on a good day, and close to boiling over on a
hot day. and of course, i'm asumeing that the rest of the
cooling system is up to par and capable of handling the heat.
and once again, i reference that i spent about a month
researching and theorizing about this heat transfer problem for
a spitfire for a university project.
--- Dean Dashwood <ddashwoo@ect.enron.com> wrote:
>
>
>
> Kirk et al,
>
> Imagine you have a 160 degree thermostat, and the coolant in
> your car is about
> 190 degrees under normal operating conditions. The thermostat
> will open at 160
> degrees, and keep the coolant temperature down to, say, 165
> degrees. Now
> replace the thermostat with a 180 degree thermostat, and the
> thermostat will
> open at 180 degrees and keep the coolant down to, say, 185
> degrees.
>
> Now imagine you have a 160 degree thermostat, and the coolant
> in your car is
> about 150 degrees under normal operating conditions. The
> thermostat will remain
> closed, and the coolant will remain at 150 degrees, right?
> Next, imagine you
> change this for a 180 degree thermostat. This thermostat will
> also remain
> closed, and the temperature of the coolant will stay at 150 -
> hence no change in
> coolant temperature, despite fitting a hotter thermostat.
>
> Next, go back to your 190 degree coolant. You're doing fine
> with a 160 degree
> thermostat. Now, re-core your radiator. The coolant will be
> cooler than
> before. (This is true even with the thermostat closed - the
> thermostat only
> blocks off one route to the radiator. The other route is the
> return route - and
> although coolant won't bed pumped this way, if the thermostat
> is closed, you'll
> get a little bit of natural convection which will move liquid
> in all kinds of
> strange directions, and some heat conduction too.) Imagine
> that the temperature
> of the coolant now drops below 160 degrees. You're now into
> that area where
> increasing the temperature of the thermostat won't
> necessarilly increase the
> temperature of the coolant. But let's say you increase the
> temperature of the
> thermostat significantly anyway. Then summer comes along.
> Now, the coolant
> temperature goes up because of the hot weather. Because of
> the hotter
> thermostat, the new radiator can't cool the coolant with the
> thermostat open as
> well as the old radiator with the old thermostat could
> (despite the fact that it
> cools better with the thermostat closed) so you overheat.
>
> This is considerably simplified, because I doubt if I could
> get it right if I
> tried to get all the details in! It's also an extreme case -
> I doubt very much
> if the coolant temperatures would get as low as in the example
> if you were
> stationary and there was no air-flow over the engine, for
> example. I didn't
> suggest that you don't change your thermostat - you probably
> won't run into
> problems if you do. I just suggested that you *might* have
> problems in the
> summer, therefore you *might* like to not change your
> thermostat unless you
> actually have a problem.
>
> Could someone else please back me up on this one, just to
> confirm that I haven't
> completely lost it? (Ok, so I lost it some time ago, but
> that's a different
> story!)
>
> Dean (probably talking complete and total codswallop again!)
> -----------------------------------------
>
>
=====
nikolai jaremka
72 spitfire mkIV
east aurora, new york
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