>In the situation of no t'stat, flow rate may be such that so little is lost
>thru the radiator that the coolant is hotter than the motor, transferring
>heat from coolant to motor, until equilibrium is reached. This is can
happen
>to race cars at rest for too long on the grid. With exotic alloy motors
than
>dump heat at a prodigious rate, like in F1, this occasionally cooks'im
>waiting for the start light. And dragsters........
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?
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.
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.
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. 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.
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