I have heard the exact same trick described on the Barracuda mailing
list, so there is apparently something to it. I think what is going on is
that a given airflow through a specific radiator lowers the coolant
temperature at a specific rate. If this rate is slower than the rate of
coolant flow through the radiator, you will not receive the maximum
cooling benefit. High vehicle speed = high airflow = high cooling rate,
but high RPM = high coolant flow rate; so in a racing situation, as you
try to keep the engine in the upper end of the RPM range (regardless of
vehicle speed), the flow rate could easily exceed the cooling rate. It
makes sense if you consider the flow rate being optimized for general
driving, not racing.
Larry Colen had this to say:
>Apparently the trick is to get a late model water
>pump pulley which will slow down the water pump. The problem is that the
>water pumps the water through the radiator too fast at high speed. I'm not
>quite sure how this works because it seems to me that there is a certain
>amount of water in the radiator the whole time, but maybe it takes time
>for convection to actually cool the water away from the edges of the tubes.
>Anyone know enough thermodynamics to explain this to an ignorant EE?
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
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