Cooling
When using a thermostat, you must make sure the air is bled out of cooling system.  This avoids air-locking engine and wounding heads, valves, guides and rings, among other things. When running a non-modified thermostat, disconnect the highest hose or fitting under the height of the thermostat and fill system until coolant escapes. This insures the heads are full of coolant, then hook it back up and top off cooling system.
Tip: Drill 2 or 3 holes 3/16 in size vertically around center control assembly on thermostat. The benefit of this modification is no special bleeding process is necessary and there will always be some water circulating through system even if thermostat is closed.
Bigger is better! especially in the radiator department. Aluminum radiators transfer heat much more efficiently than copper or brass. Shrouds are a must, and proper fan spacing is critical. On gasoline, air boxes in front of radiator are necessary. Also use reduced ratio pulleys to slow water pump speed. Use a 5/8 – 3/4 water outlet restrictor in thermostat housing. Ask us about running thermostats, it may fit your situation.
If extra cooling is needed add 1 -2 qts of Below 40 additive, Water Wetter doesn’t work as well and it benefit fades away in a few weeks.
Tip: Run a rippled type suction hose (to water pump) that has the wire embedded inside the rubber. We’ve seen hoses suck closed on engines at speed and flow no water. Don’t use hose with the visible wire in them as they will end up in your water pump fins and destroy the pump and then your engine.
Cleaning your radiator – Dirt track racing has a bad habit of filling cooling fins with dirt. Pressure washers and air pressure won’t clean these without damaging fins and ruining the radiator. It is better to clean a radiator by submerging it under water for a short time to penetrate all the dirt thoroughly and rinse with a garden hose and light air pressure.