Jim, by the same reasoning, when you are hot and sweaty in front of your fan
at home: The slower the fan turns, the colder you get since the air has more
time to pick up heat from your body? :)
Buly

>
> I had looked at it as:
> High Flow - engine can't heat the water as much as it would if the flow
> were slower and there was more time to heat the water, resulting in less
> temp rise in water across engine and more uniform temps in the block.
> Water emerges from block not much hotter than it went in.  Water doesn't
> stay in the radiator long enough to be exposed to air flow long enough
> to be cooled very much.  Good news: it doesn't *have* to be cooled much
> - it's not all that hot.
> Low Flow - coolant spends more time in engine and gets hotter.  Greater
> dT across engine block, coolant hotter exiting engine and entering
> radiator.  Radiator has to draw more heat out of the coolant to get it
> back to acceptable block entry temp, but has more time to do it on
> account of lower flow.
> What I hadn't seen, is how apparently wide a range of flows would
> produce acceptable results.  I suppose a better radiator (more flue
> area, better air flow, etc. - better cooling per in^3) would reduce the
> volume requirement.  Lower limit on flow would seem to be that flow at
> which the temperature gradient across the engine becomes unacceptable.
> Thanks for the details ... Jim S.