quote:Originally posted by Cowboy from Hell:
The swirl tank (which DeTomaso called a system tank) is actually the least needed of the two. It is non-functional with a radiator cap on top anyway.
Keep the tall tank (expansion tank), mount it as high as possible, connect the lower connection to the suction of the water pump, add a fitting near the top of the tank to allow connection of the radiator vent. Run the expansion tank (which is now a header tank) with an air space above the coolant. I suggest the tubing between the radiator and "header tank" should be at least 1/4". Thus modified the radiator will auto-vent instead of trapping air, the car will run cooler and be easier to fill with coolant.
The purpose of a swirl tank (properly called a swirl pot) is to trap any air that is released as steam in the cylinder heads and vent it to a header tank, that's why its located on the outlet of the engine, its supposed to trap the air before it has a chance to circulate through the cooling system.
The radiator is where all the air in a Pantera gets trapped, so the radiator vent is the most important vent to "make functional". As it came from the factory it didn't function, because it was connected to the "system tank" which is higher in pressure than the radiator. Air will only flow to a zone of lower pressure than where you are trying to vent it from. A header tank is a necessity to vent air in any cooling system. The revision I detailed above converts the expansion tank into a header tank and makes the radiator vent functional.
-G
In this modification, what happens to the tank caps. As existing, one is a high pressure and the other is just a cap with no pressure.
Are you suggesting to make the existing overflow tank pressurized with a pressurized cap?