[WorkinLonghorn]

I thought this info from the Stant website was interesting;

"My thermostat has a jiggle pin but the Stant thermostat doesn't. Will a Stant thermostat still work?

Yes. Many thermostats have a “jiggle pin” that allows trapped air in the cooling system to pass through the thermostat and be released from the system. Some Stant thermostat do not use have a jiggle pin. These thermostats will have a "bleed notch” or other method of removing air from the system."


"As the engine's coolant warms up, the increase in heat causes the wax to melt and expand. The wax pushes against a piston inside a rubber boot. This forces the piston outward to open the thermostat. Within 3 or 4 degrees F. of the thermostat preset/rated temperature which is usually marked on the thermostat, the thermostat begins to unseat so coolant can start to circulate between the engine and radiator. It continues to open until engine cooling requirements are satisfied. It is fully open about 15-20 degrees above its rated temperature. If the temperature of the circulating coolant begins to drop, the wax element contracts, allowing spring tension to close the thermostat, thus decreasing coolant flow through the radiator. "


http://www.stant.com/index.php/engli...rmostats/faqs/


Although frankly, I don't see how air would survive the first time that you got the thermostat fully open and coolant was gushing through there to the radiator. And of course the coolant going into the engine again is from the bottom of the radiator, so no air there.

Never drilled and won't start now! -BA