On Wed, 19 Mar 1997 Larryhoy@aol.com wrote:
>
> Hi Ray, I feel the same way you do. The only thing that makes me wonder
> somewhat is I have heard that many factory racing teams (including MG in
> their day) replaced the thermostat with a special flow restrictor,,,,, hmm.
>
> But I will need a little more hard evidence to convience me.
>
> Anyone out there run their car without a thermostat?
>
> Larry Hoy
Please understand what I'm saying. I believe there may be circumstances
when a flow restriction *does* help cooling. *If* that can happen, and I
am not at all certain it can, I contend it happens for some reason other
than a slowing of the flow through the radiator. Possibly there are some
unusual circumstances when a small restriction actually speeds up flow.
Perhaps the water pump cavitates without a restriction, who knows. As a
teacher, I dislike bogus explanations even if they sometime lead to the
right conclusion. My ex wife was absolutely convinced the sky was blue
because it was a reflection of the ocean. Used to drive me nuts.
What i disagree with is the old explanation that you have to slow down
the water passage through the radiator, to give the water time to lose
its heat.
I cannot imagine that you use a thermostat in winter, because it slows
down flow and makes the engine run hotter, then use a thermostat in
summer because it slows down flow and makes the engine run cooler. Yeah,
right.
This has gone round multiple times; I may write a submission for Kai's
FAQs. Someone wrote me that it was a classic problem in heat transfer to
determine the optimal flow rate through a radiator. But he never told me
any more than that. So I don't know what specific problem he was talking
about, and don't know if he was correct, or that it was applicable to a
closed loop with a heat source and a radiator. For the reasons given
above, I doubt it.
WRG
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
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