I have always heard that if you remove the thermostat it will
circulate the
water really fast through radiator. Thus the water does not stay in
contact
with metal of radiator long enough to transfer heat.
I've heard it multiple times too. No basis in fact, but like
most "wives' tales", it will never die.
Heat transfer is complicated. That much I _do_ remember from
school. It's a circuit, so the heat-picking-up end also needs
to be considered. I wouldn't take anything as gospel except
some empirically-proven (also) textbook type of treatment.
Y'know, something like "Radiator Design and Construction
for Industrial Equipment", copyright 1947. (I made that up.)
-- Jim
