Brock,
In your thermal answer I believe one should also consider that the
diving force for moving the water is the pump. The flow rate is
dependent
not only on the resistance (electrical analogy) of the fluid pathways,
but the pressure differential developed across the water pump (voltage).
To simplify this, E=IR, where E (voltage, or pressure differential), I
(current, or flow rate), and R (resistance to flow).
If one were to reduce the resistance, by eliminating a flow restrictive
element, (thermostat) then the flow rate goes up. There are practical
limits to this, and the one that is most important is that there must be
sufficient system pressure to prevent the cavitation of the water pump.
If this happens, it's ability to pump adequate pressure drops
significantly (E drops), therefore I (flow rate) drops. Keeping a
higher system
pressure on the pump inlet raises the capability of the pump to resist
flow destroying cavitation.
So, even though I have used an electrical analogy, there is a difference
between electrical and hydraulic systems in this "cavitation"
influence. Although the heat transfer coefficient can be considered as
a resistive element to heat flow, there is no equivalent to localized
nucleate boiling that destroys this capability, so even localized
"boiling" crates a gas barrier to heat flow. This can be caused by too
high a
flow rate over rough surfaces creating vortices, too high a local
temperature (hot spot), or a rapid increase in volume, which drops the
local
pressure below the boiling point for the fluid.
Hell, if it were simple, we'd never have overheating problems. Too many
variables, including air flow thru the radiator, and pressure
differential across the radiator, make generalizations impossible.
In my case, I increased the radiator surface area with a modern high
tube count, high fin count, four row radiator that fits the original
tanks. I
added the Ford "Canadian" 6 blade fan. The engine back flushed. The
thermostat was replaced by a 180 good quality Stainless steel Stant
that had a 1/8 inch hole drilled thru the valve plate. A small water
recovery systems just fits between the expansion tank and the radiator
header. A Gano filter was installed to keep the inevitable scale from
the motor out of the radiator (that's what killed the last one). Great
care
must be used in locating the unit and assuring the clamps are securely
tied together. To finish the job, I am using 50% distilled (NOT
de-ionized) water and good quality anti freeze. Car runs just above
thermostat in cool to moderate (78 deg.) weather, and at about 195-200
on
hot days. Idling in bumper to bumper traffic is a challenge, and if I
find that a problem, a 12-13" electric fan is going in front of the
radiator.
A small "air dam" ,behind and underneath the front valance, is another
possibility to allow a low pressure region to develop behind the
radiator.
Anyway, those are my thoughts, and my solution.
--
Steve Laifman < One first kiss, >
B9472289 < one first love, and >
< one first win, is all >
< you get in this life. >
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