Reply to "Pantera #6018 - Photos & Stories."

Ford corrected one cooling system problem in 1971 by re-engineering the radiator core. The cross sections of the tubes in the original radiator core were so small that the core trapped air, and the trapped air would then restrict coolant flow. So Ford specified a replacement radiator core with larger tubes.

Ford also revised the coolant pump inlet plumbing to clear the shift linkage, but by doing so they also eliminated a coolant hose that had a proclivity for collapsing at low rpm. This was the second cooling system improvement.

Finally Ford revised the radiator baffle circa April 1973. They replaced the  original vertical baffle with a horizontal baffle because the vertical baffle allowed coolant to bypass the radiator.

Equipped with these 3 improvements my 1974 Pantera could idle with the air conditioning running on a summer day without over heating. But the cooling system was still "fragile". It would overheat in certain stop and go situations, such as freeway driving in afternoon commuter traffic on hot summer afternoons.

Ford had resolved three big problems by 1973, but what remained were two cooling system issues stemming from the cooling system’s basic lay-out and execution. The two problems are insufficient flow at low rpm and air collecting in the radiator. There is a third problem,  the electric radiator fan control circuit is dysfunctional as designed … the fans run all the time … and they cause the engine to "run-on" when you try to turn it off.

There are four steps I took to improve coolant flow in #6018.

(1) I utilized a radiator with a low-restriction core design. I chose the Hall "Phoenix" radiator (copper). The Hall radiator has a horizontal baffle.
(2) I utilized the coolant pump sold by Flow Kooler (p.n. 1648) which has a billet impeller designed specifically to improve low rpm coolant flow.
(3A) I made sure there were no sections of radiator hose between the radiator outlet and the coolant pump inlet that could collapse due to vacuum. Gates green stripe hose, wire wrapped, (vacuum rated for 25” Hg) was employed. Part number 24922 (1-3/8 inch - 35mm - ID hose) for most sections, and part number 24928 (1-3/4 inch - 44mm - ID hose) for the connection to the coolant pump.
(3B) Gates 2 ply green stripe hose (not vacuum rated) is good for all other applications between the engine coolant outlet and the radiator inlet. Part number 24222 (1-3/8 inch - 35mm - ID hose).
(4) I installed a 10% over-drive coolant pump pulley available from IPSCO (# IPS260-OD).

Having the Hall radiator installed in an upright position, and having the Miriah fans installed in the OEM brackets, helps to maintain the OEM appearance of the car.

The issue of air collecting in the Pantera radiator can be resolved in one of two ways.

1. The simplest way is to install a manual bleed valve (drain petcock) in the top of one of the radiator tanks and develop the habit of regularly bleeding the air from the tank manually.
2. The better way is to revise the coolant recovery tank to perform as a head tank, thus providing a functional place to plumb the radiator vent within the cooling system (radiator venting can then take place automatically).

I chose the second method.

I also installed new stainless steels tubes, Hall Miriah fans, and Hall stainless steel  tanks. The recovery tank had 3 tube fittings added which turned it into a head tank. The radiator cap neck was removed from the system tank and a tube fitting was added to the flip side, which turned it into a functional swirl tank.  I installed the correct thermostat in the 351C, and I revised the fan control circuit.

duz185 posted:

William, excuse my vulgarity.