Which coolant is better; liquid helium or liquid nitrogen?

Better? What is better, a hammer or a shovel? They are different tools for different purposes; they are incomparable, and so are liquid nitrogen and liquid helium. If you need nitrogen temperatures (~77K), use liquid nitrogen. read more

The radiator may hold less than a third of the coolant. The radiator may have an air bleed or plug on top of the tank or the side, and if it does, open or remove it. Next, open the drain cock. Collect the coolant in a pan. Next, disconnect the lower radiator hose from the radiator and let coolant drain from the block. read more

Assuming a 100-gpm (gallons/minute) coolant flow rate and an energy loss through the coolant system of 189.5 hp, the water temperature increase would be 10 degrees, the ethylene glycol water mix would gain 20 degrees, and propylene glycol would gain 33.3 degrees. read more