How hot does your engine run? Is it on the cool side? The hot side? Where should it be? How big of a radiator should you run? Antifreeze or water? Tap or distilled? Do you need a pressurized cooling ...

Granted, a book could be (and probably has been) written about each aspect of the cooling system of a race car (and you should go find them and read them). Though we don't have the room to cover ...