I hope this not a repeat posting as I haven't followed this thread. The
factory shop manual for MGAs discussed a coolant restricting piece that was
recommended to racers to be put in place of a thermostat. The reason for it
was to slow down coolant flow so that the cooling system would perform more
efficiently in racing situations. Thermostat blanking plate I think it was
called.
>>> Barrie Robinson <barrie@look.ca> 12/7/2005 4:32:30 PM >>>
Well, my email about cooling in relation to water flow seems to have
stirred up a hornet's nest. I have tons of information for which I
thank one and all. There was a definite chasm between the
experienced 'racer' types and the engineering types. One thing is
positive - there are many factors to consider but the fundamental
question is still paramount in my search. That is, does flow rate
effect the rate of heat dissipation from the radiator?
Having considered all the replies it would seem that fast flow of
coolant is better than slow. The problems found by removing
thermostats and causing cooling problems is probably not because of
increased water flow - but due to other effects. My main reason for
coming down to this side is a basic premise that if it is better to
have air belting over radiators (powerful electric fans) then the
same must apply to water screaming down the radiator tubes. The
other is a simple premise, slower water will take up more heat and
thus the temperature difference between it and the tubes cooled by
air flow is made smaller. I believe this difference squared is
proportional to the heat transfer - (help me here folks as it is over
40 years since I read thermodynamics) the bigger the delta the higher
rate of transfer. So we get less heat transfer the slower the water
goes through the radiator.
One point that was made was that the removal of a thermostat resulted
in a lowering of the pressure to the block (water pump hump!), which
dropped the boiling point, which effected cooling.
But most compelling was a web page from Stewart Components
www.stewartcomponents.com (Tech Tip 3) sent to me by Jim Stuart. It
laid it all out and said slow speed water is a myth -
However after the Christmas holidays I shall set up a test rig just
to test flow against heat dissipation. .....and maybe the use of
Water Wetter about which I have doubts.. And before I get emails
saying all the NASCAR people use it - they also use STP, Coca Cola,
Febreeze, and used to promote cigarettes.
Regards
Barrie
Barrie Robinson
(705) 721-9060
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