>
> If the coolant is hotter than the motor, then the radiator is generating
> heat. Where is the heat source for the radiator? I thought it was the
> engine. How can the cooling device be hotter than the heat source?
=======
I was tired, preoccupied, and rather poorly stated the point I was trying to
make.
In the case of F1, Indycars, and some sports prototypes, the shrouded
radiators 'hot soak' from the surrounding flow tunnel. Consequently the
ambient air increases to the point where there's ~no transfer at the
radiator, raising coolant temp, since there's no cooling fans installed in
the ducts. The high tech alloy motor becomes a heatsink, heating the coolant
faster than it can dissipate it. Same as if a thermostat refused to open.
=======
>
>
>
>
> To conduct this experiment in the lab
> Get a flask, heat source, variable rate pump and distillation tube. Heat
> the water in the flask. Pump the water through the distillation tube
(which
> cools it) and back to the flask. This simulates an engine and radiator.
> Run the system to equilibrium and check the water temp in the flask.
Repeat
> at various flow rates. At very low rates (turn the pump off) the water
will
> boil. At very high rates, the water will be close to the temp of the
> cooling water in the dist tube.
=======
Sorry, no chemistry set here. :^((
=======
>
> To conduct the experiment in the field
> Make several restrictor plates. Make a plate that will fit in the
radiator
> neck under the radiator cap. Punch holes of various diameters in the
> plates. Run the engine until the temperature is stabile. You will find a
> relationship between restrictor size and temp. You believe that the
pinhole
> restrictor (lowest flow) will result in the lowest temp; I believe the
least
> restriction (highest flow) will result in the lowest temp.
=======
I don't believe that the most restriction will have the lowest temp, neither
do I believe that the least restriction will have the lowest temp. Too low a
flow rate will cause equilibrium too fast in the radiator for it to be of
any use. Too fast, and the radiator becomes the restrictor, causing the pump
to cavitate from excessive back pressure, reducing efficiency.
=======
>
>
> A final point : The purpose of the thermostat is to warm the engine. You
> want the engine to warm up as rapidly as possible from start and you do
not
> want the engine excessively cooled in winter. The thermostat does this by
> restricting the coolant flow, either completely or partially.
=======
Agreed.
=======
>According to
> your theory of max flow = less cooling, the thermostat should work the
> opposite of the way it does! When the engine begins to overheat, the
> thermostat would close partially, restricting flow thereby increasing heat
> transfer to further cool the engine. But, that ain't the way it works.
=======
The t'stat is closed until it senses sufficient temp to begin to open. It
allows coolant through until it senses a temp drop, and partially closes.
The system reaches some equilibrium WRT the radiator's dissipation / coolant
flow. The only time the t'stat is wide open is when the radiator can't keep
up for whatever reason. In theory, with a properly designed and functioning
system, this will never occur. If it does, then more air has to flow through
the coils. According to you, we have a second option of revving the motor to
increase flow. AFAIK, that ain't the way it works, it just gets hotter.
It's the ratio of coolant flow to the radiator's variable dissipation
capability that keeps the temp ~stable, and it takes a t'stat to regulate
it. Since the t'stat shouldn't be WFO for any length of time, I still think
my original statement; "When you run without a thermostat, the water moves
too quickly through the radiator for much heat transfer to take place" is a
valid one since the t'stat does keep it from flowing at it's max all the
time, though it may be flowing at the radiator's maximum rate.
All that's left is to explain why 'slower' in this system doesn't run afoul
of ya'll's assertion that Mother Nature decrees that faster = cooler.
GM
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