[G.M.]

I have run 100's of heat tests in Florida on 90 degree or
warmer days. I use a 24" Lasko square box fan sitting on
the bumper and laying against the bottom of the grill.
With the fan on high, the radiator FILLED up in the filler
neck, plain water, 2 bottles of Purple Ice and 1 gallon of
Prestone perminate and a large bottle of Barr's stop leak,
the type with copper flakes. You need a 2 lb pressure cap
or a tight sealing early type cap. In order to get the early
caps to seal you need the drill the rivet out, cut a round flat
gasket out of the thin red rubber gasket material found in
the plumbing section of your local hardware store. Replace
the rivet with a stainless steel slotted 1/4 x 20 screw.3/4"
long with lock washer and nut, put a little lock-tite on the
threads. Run the engine at a speed equal to about 20 MPH.
If coolant come out the over flow make sure you don't have
a compression leak. After running for an hour or more shut
the engine down, DON"T remove cap and let sit over night,
the slight pressure in the system will force the stop leak into
any small pin hole leaks and seal them. The temp in this test
should not get over 195. Temp in these old Ford engines is
controlled by The amount of coolant in the system and the
gallons of coolant pumped through the system every 5 minutes.
Don't believe the story that the coolant is going through the
engine to fast. Modern and reproduction pumps move 55 to
65 gallons off coolant through the engine every 5 minutes,
Skips modified pumps move 110 gallons every 5 minutes.
The cooling effect can be measured with a laser pointed
temperature gun at the bottom and about 4"s from the top
of the radiator. We also notice on the water pump test machine
which is a sealed closed circuit the same as the radiator that
after a 5 minute test run of a pump that when the cap is
released there is very little air in the system compared to a
stock pump. This is due to the fact the impeller and it's tight
controlled clearance with the seat is pushing water and not
slipping in water making air. When the cap is released with
a stock pump there is a gush of air and on Skips pumps there
is hardly any air. A clean block, heads and radiator are required
for good heat transfer. This is not intended to be an add for
Skip, just the true facts found after over 20 years of rebuilding
Ford pumps. Read the results posted of people using Skips
pumps and they tell the real story. G.M.