I have a Pantera which is similar in layout to the GT-40 with radiator
in the front and engine in the back. While the radiator is in the front,
the pressure and recovery tanks are mounted near the engine. Panteras
got a reputation for cooling problems due to several different problems
but when the system is operating as designed, it cools quite well.
Off the top of my head, in no particular order, here are the cooling
problems that I've heard of from the guys in the pantera club:
fans slow down - This happened on my car. One of the original electric
fans began slowing down and the car started running hot. I installed
a new pair of fan motors and it now runs cool in 100 deg F weather with
the air condition on. A stroboscope can be used to check the fan RPM.
bleeding - Bleeding is a trick on these cars. It took me 7 or 8 bleeding
cycles to get all the air out when I did a cam change. My radiator has a
hollow bleed screw with an intersecting hole. The screw passes through a
banjo fitting to a line that runs all the way back to the recovery tank.
This is supposed to keep the system bled but first you must get all the air
of the system.
radiator - The stock radiator is a 2 pass design with an internal baffle.
These baffles can work loose, resulting in much of the radiator being
bypassed.
improperly wired electrical fans - It's not unusal for a new owner to find
one or even both of the electric fans wired up to turn backwards. Just
because the fan is spinning doesn't mean it's moving the air in the proper
direction.
distributor pin - This one is very common. What happens is the
oil pump
gears momentarily jam (often due to sucking up a small piece of decayed
oil seal) and the pin that locates the distributor gear shears, allowing
the gear to rotate and then jam. The result is timing is retarded a bunch,
leading to sluggish performance and overheating.
water pump - Panteras use a stock Ford 351C pump and it doesn't seem to
be a problem even with the additional distance the coolant must travel.
The best replacement pumps appear to be the Edelbrock aluminum pumps. They
use an impellor with a properl curved vane rather than the usual replacement
pumps with a paddle whel in a box.
thermostat and block ring - This is specific to 351C's (and 351M/400's)
but I'll mention it here anyway. The Cleveland thermostat is unique with
a shoulder which is sized to match the brass restrictor ring in the block
which other thermostats do not have. Using a Windsor thermostat (which the
parts counter monkeys will give you half the time) will lead to overheating
because coolant will bypass the radiator.
sucker versus puller fans - I still have the pusher fans but some in the
Pantera club claim the sucker fans are superior, FWIW.
I noticed you mention a Snow White waer pump. I have something in my database
(might be from Dave Wharren, I only show Dave) on those pumps. I'm not sure
if any of this applies or not but I'll list it here just in case:
"The pump is made by Snow White LTD. (4743 Lamona, Fresno, Ca. 209-255-0527).
It fits either Cleveland or Windsor blocks. The plate that bolts to the motor
is aluminum, about 1" or so thick. The pump comes from an Opel GT of all things.
One thing not on this setup is the warm up by-pass that is normally an internal
function on a standard Cleveland pump. It allows water to flow through the
engine without going to the radiator. Flow during warmup is through the brass
orifice below the thermostat until the thermostat opens. The hole is then plugged
off by the bottom of the thermostat.
There are 2 possible solutions. Snow White tells you to drill a 3/16 or 1/4 hole
in the thermostat to allow a small flow past the thermostat until it opens. I've
been running my engine on the test stand with this configuration, and it seems to
warm up pretty quickly with a smooth transition as the thermostat opens.
Another way would be to drill and tap the 1" thick plate so an external fitting
could access the "recirc" hole in the block. The pump has a fitting on it's inlet
that is used for the heater (I think!) on the Opel. It's plugged for my application,
but a hose could be run from here to the tapped hole in the plate to provide the
by-pass.
This setup is supposed to be about the same length as the Ford "shortie" pump for
the Windsor's. The Opel pump has a 2" suction opening in it. "
Hope This Helps,
Dan Jones