mtwoolford

On conventional small blocks / L98, the pellet is the circular tube dead center in the thermostat

neat

I ran without one for a month or so last winter while hunting a coolant leak. The car took forever to warm up, and going down the highway the engine wouldn't break over about 55 degrees C. The engine oil temp gauge would never come off the peg either.

86PACER

Arron Johnson strongly opposes that "too fast through the radiator" theory. He states that if that where true then the same coolant would also be flowing too fast through the engine block to pick up any heat at the same time.

http://www.badasscars.com/index.cfm/...rod/prd280.htm

The only times I've ran cars without the T-stat was strictly for diagnosing certain cooling system problems. My observations here in hot California weather where that the car would take noticeably longer to reach the same operating temperatures vs with the t-stat (specially from a cold start) but would still eventually reach whatever max temps the engine wanted if sitting in traffic. Once the t-stat is open it's open and no longer has control. This is why when t-stats fail in the open position one of the signs is extended warm up time not overheating. This is also the principle behind "fail safe" thermostats that are designed to fail in the open position to save the engine from overheating damage.

I have also found this to be the case on different types of vehicles. The reason is that the coolant is already freely flowing through the system right off the bat. When the stat is present and closed on a cold start the coolant is trapped at a stand still soaking up heat inside the block. This shortens the time it takes the engine to warm up and go into closed loop. Then once open regulate the engine's minimum temps. When the T-stat isn't there or fails in the open position coolant is already flowing though the system and radiator right from a cold start.

tpi 421 vette

One thing is the thermostat also serves as is a restrictor to a point. If you don't run a thermostat, it is still recommended to run a restrictor. Both the thermostat and restrictor serve to allow the block to completely fill with coolant. That keeps the top of the engine full of coolant, which will keep it cooler.

I had a friend a long time ago port his water ports on the head gaskets to match the block. It wouldn't keep fluid full at the back of the block, and constantly ran hot. He ended up changing back to a stock type head gasket, and the problems were gone.

anciano

You'll freeze your *** off in the Cincinnati winter. One day driving in the Sierra through snow flurries the thermostat on my car (at that time a 240SX) stuck open and the heater blew nothing but cold air, more or less ambient temp since it was being drawn from the outside and had almost no warming from the heater core.

DAVECAD2.0

Once again. The T-stat doesn't determine the "normal" operating temperature at which the engine will operate. The radiator does. The T-stat simply determines how fast it heats up to "normal". The circle track guys don't run stats simply because it's a potential failure point. Not because the engine would run cooler. There would be no point in then installing a restrictor plate. In theromdynamic terms an orifice.

93Rubie

Are you guys racing (competitively) and looking for every single little thing to win? Or are you just running it on the street, strip, auto-x, track use? My point is this these threads are dumb, we debate over something so stupid. ALL street and production cars have a t-stat from the factory. Just about every engine (liquid cooled) on the planet has one. Put the darn T-stat in the car, and don't worry about it. Please stop with these ridiculous and childish threads, they are totally pointless.

Running no t-stat is bad, and dumb. Put it in and be done with it.

CFI-EFI

BULL!!! If the water isn't in the radiator long enough to cool properly, it won't be in the engine long enough to get hot. The purpose of the thermostat is to cause a fast warm up. With no stat or too cool of a stat, the engine doesn't get up to proper operating temps soon enough. That causes increased fuel consumption and increased engine wear. Bad idea!

Race on!!!
Jim

86PACER

I'll just speak for myself. I never once have suggested or recommended that anyone remove their thermostat and run without it. I simply do not believe that a car without one will overheat. The only times I ran a car without it was to diagnose certain cooling system problems. That's it.