Two schools of thought.

School A:
Thermostats, even while fully open, are a restriction in the coolant lines. Removing it totally causes fluid to move so rapidly through the radiator that proper heat transfer cannot occur. The end result is a engine running too hot.

School B:
More coolant you can get through the better. Removing the thermostat will cause your engine to run very cool, maybe even too cold for maximum efficiency.

So....

 

in my experience i've found that taking the thermostat out is a bad thing to do. The cooler coolant in the radiator replaces the hot coolant in the block. If you dont let the coolant sit in the radiator then it isnt able to be cooled to the proper temperature. it will only drop a few degrees from the water in the block. the effects of removing the thermostat is that it takes much longer to warm the coolant, so that if you are only running it for a short period of time, it stays pretty cool. however, if you keep it operating for a length of time, the water will just get hot, it doesnt spend enough time in the radiator to cool down properly.

Anyone who has a clue about cooling systems will tell you that. i've never heard the ideas presented by School B, and it really doesnt make any sense. if you want your car to run cooler, put a lower degree thermostat in. running without a thermostat should really only be done in emergency situations if your thermostat is stuck closed.

 

Bad for emmissions also since theres no check on how cool the car can get.

The restriction of a thermostat shoudl be no biggie to the coolant system. If your having a hard time keeping the car cool have the radiator flow checked.

 

Im not having issues either way, but we are discussing this in a class at school