>
>Actually , it's really 60/40 gives maximum protection.
> Compromise? Shoot, water boils at 212, most of these trucks run
>hotter than that so they'd boil over. Also, straight antifreeze boils
>at a lower point that a mixture too. And on the other side of the coin,
>each pure item freezes at a higher temperature than a mixture.
You are right, a little mixture away from 100% pure will raise the boiling
point and depress the freezing point. Pure water may not boil in a cooling
system since it is under pressure, which raises the boiling point.
> Here's something that many of you may not realize, and I'm open to
>discuss. -Just because you have a 180 thermostat doesnt mean your
>truck runs at 180. It means the t-stat doesnt allow the antifreeze
>to circulate to the radiator to cool it down until the antifreeze in
>the motor reaches a certain temperature. After the t-stat opens, the
>antifreeze still gets hotter. Most vehicles run around 205-220
>nowadays.
>
The thermostat does have a performance curve. The perfect 180 thermostat will
crack open at 180 and be fully open at 180.1. This can't happen and it takes a
few degrees for it to open all the way. Still, a thermostat will keep the
engine in a tight temperature band over a range of conditions.
Also, the temperature in the cooling system will vary with location. It is going
to be cool at the radiator outlet and hot around the heads. I would not be
suprised if you get localized boiling near the exhaust valve. Of course this
would not be a problem since the bubbles would collapse once they leave the
surface. Thermostat keeps the temperature at the thermostat constant. The
rest of the engine does its "thing".
I posted an article by Texaco to the DML about 3-4 months ago with curves and
all sorts of technical information. It was more than anyone wanted to know
about coolant. The article was long so I posted it in 4 parts, each one
apeared in a seperate digest. You can get it from the archives by searching on
Texaco.
>Any responses?
>
>Patrick
Drive Safe,
Joe Dille
Telford PA USA
(joe@dille.montgomery.pa.us)
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