Bob Hutton wrote:
<snip>
>
> It involves moving the thermostat from the hot water outlet at the top of the
>engine to the cold outlet at the bottom of the radiator.The thermostat's put
>into a small housing in the outlet hose with the business end of it facing the
>engine. A 5/8" hose is cut into the top radiator hose and then into the new
>termostat housing so that hot water is directed onto the the thermostat.
>
> This effectively bipasses the radiator and puts the hot water from the head
>straight back into the block. The hot water cracks the thermostat open and
>allows in only a little cold water from the radiator before closing.
>
> The theory is that there is so much cooling effect available in the bottom of
>the block because of the continual in-rush of cool fuel/air mixture, that in
>normal driving, the radiator is not needed at all. In the normal system,
>you're throwing away all that heat energy produced by burning petrol. In this
>system it's all put back into the engine, a) to heat the bottom of the block
>(and number one cylinder, which typically always runs cold), b) to even out
>overall engine temperature and c) because
>
<snip>
>
Aha! Finally someone has put forth a possible explanation for what I
thought was just a very stupid location for the thermostat on my '79 and
'84 Volkswagen Rabbits. They have the thermostat in the bottom of the
water pump, located at the bottom of the block, and being fed from the
bottom of the radiator. There is a bypass hose that comes down from the
head and another hose on the pump that I can't remember right now where
it goes. I always thought it was just poor design that caused me to
have to drain the whole cooling system to change a thermostat, when so
many other cars make it so easy by having the thermostat right up on
top. Silly me! I should have known that there was a reason behind it,
considering that the engineering was done in Germany. Live and learn!
Thanks, Bob, for the answer to a long time question.
Mike Frerichs
maf@radiks.net
-- I only became a programmer so I could do virgin control! --
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