Michael D.,
A+ for this response! Written to the point, including all applicable
information, no unncessary formulas to confuse the layman, no mention of
the water not having enough time to cool off in the radiator when the
thermostat is removed :-)
Defiuntely a P.E.
Ulix, PHDME2B
On Mon, 26 Apr 1999, Michael Dietsche wrote:
>
>
> --- Michael Graziano <mgrazian@ltcm.com> wrote:
> > Hey all. Just a quick question, and a quick story.....
> >
> > 1. WHat's the difference between a 160 degree and a 180 degree thermostat
> > besides 20 degrees? i.e. which should be used when? And when I went to
> > change mine, I found that the DPO didn't have one installed. Is this
> > indicative of overheating problems?
> >
> The thermostat sets the minimum temp of the coolant in your system. It blocks
> the flow through your radiator until the temp hits the set point, then
>releases
> flow. Your operating coolant temp will therefore be in a range between the
> thermostat set point (the minimum), and the equilibrium temp of your system in
> full flow (the maximum temp it stabilizes at). If the radiator is inadequate
> or you have other problems the "maximaum" will be an overheat condition.
>
> Thermostats have different setpoints for different seasons or other
>variables.
> For instance, you may want a higher minimum in the winter, since the cold air
> may keep a freeflow temp in the radiator too low to ever really warm the car
> up; so you'd use a higher setpoint thermostat to keep the temp up to that
> desired minimum. In summer you have a different situation, with hot ambient
> air taxing the system's ability to dump heat even in the freeflow condition,
>so
> then you might use a thermostat that opens earlier to get it into freeflow
> quicker, although this isn't as big a help as most people think -- if you're
> overheating, and the thermostat is an ok type for the car, you really have a
> malfunction or radiator/flow problem.
>
> Some people remove the thermostat entirely in the summer for the above reason,
> or because they can be unreliable and stick closed, causing overheating.
>DON'T
> do this unless you know what you're doing! Removing the thermostat can change
> the coolant flow pattern and cause localized overheating (hot spots) at
>various
> places in some engines. If you are determined to remove the thermostat at
> least put a gutted one in there to keep the flow pattern close to the original
> design. Also, if your car has a water choke, using too cold a thermostat or
> removing it may cause choke malfunction, if the coolant never reaches the
> choke's trip temperature. If this happens your choke might stay on all the
> time.
>
> Best bet is to keep your system in good shape and use a good quality
>thermostat
> in the manufacturer's suggested range. If you have a water choke use a
> thermostat on the high side of the suggested range, to make sure your choke is
> turning off. Besides, car engines run more efficiently at higher temps anyway
> (within reason, of course!).
> ===
>
> Michael B. Dietsche, P.E.
>
Ulix __/__,__ ___/__|__
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'67 Sprite '74 X1/9
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