It's probably more about the reduced pressure allowing bubbles to
form--something engineers call nucleate boiling. I don't know about this
"water moving too fast through the radiator" notion. Usually rapid flow is
good for cooling because it keeps the boundary layer thin. My
thermodynamics classes were thirty years ago, but the amount of heat that
a heat exchanger can transfer is a function of mass flow rate. More is
good. Of course that's theory, and then there's practice, where a whole
bunch of complicating chaotic factors get added to the mess.
-----Original Message-----
From: WEmery7451@aol.com [mailto:WEmery7451@aol.com]
Sent: Saturday, March 01, 2003 12:38 PM
To: fot@autox.team.net
Subject: Head Cooling Problems
In a message dated 2/27/03 7:13:45 PM Pacific Standard Time,
cartravel@pobox.com writes:
<< This must be a helluva cooling problem, since its running 230 degrees
on a
70 degree day. I've
already got a radiator with no crank hole (not sure what type of core).
I've got the oil cooler mounted behind a hole in the front apron and
everything is shrouded to force all air through the radiator. >>
These conditions remind me of a screw up I pulled in the late 60s. I took
out the thermostat and didn't replace it with a restrictor washer.
Thinking
that I would improve the engine cooling, the temperature soured out of
sight.
If the water travels too fast through the radiator, cooling capacity is
reduced. Also, I might have been pulling down the block pressure to the
point that the coolant was flashing to vapor.
Several of us were then for a period of time by shimming the radiator caps
with rubber washers, which we cut out of gasket material. This practice
kept
the coolant in the system, until a hose would blow off or the packing
would
blow out of the water pump.
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