Bow94z

Trying to settle an arguement on another board, lets hear some Pros/Cons of running no Thermostat in a car..Doesnt have to be an LT1 either..

RE AND CHERYL

You can't run an LT1 with the thermostat removed. Because of the reverse cooling system, the LT1 will not cool with the thermostat removed.

Removing the thermostat can cause overheating on some cars because coolant flow through the engine is accelerated to the point that it dosn't absorb enough heat to properly cool the engine. In other cars, removing the thermostat will cause severe overcooling not allowing the engine to come up to operating temperature. This will cause accererated wear on the engine and increased fuel comsumption in a fuel injected vehicle because the PCM thinks the engine is still warming up and is dumping extra fuel.

Run a thermostat.

1racerdude

I am not running one with the Evens cooling and elect WP. I was told not to by Evans(THE cooling people) and plug the bypass hole in the housing below the "T"stat.

As far as a SBC if it's going to run hot,from a mistake building it,it will do it with or without the T'stat it just will take a while longer with no T'stat.Ya CAN put enough radiator in one to keep it cool but a normal engine will run in the 160/170 range in town and a bit cooler on the highway.
Have run many a car with no T'stat.

shoebox

The passages in the LT1 pump make it different from an SBC. If you don't plug the bypass port, then you should run a thermostat, so the coolant will be directed properly. If someone like Evans suggested not to run one, then I might be inclined to heed their advice, since they pretty much wrote the book on reverse cooling. Your run of the mill street driven LT1 should be fine with a thermostat.

marshall93z

I, too, have ran without one with no problems.

TripKidd

I would just like to pop in here and say that although you may be right about the engine not cooling properly without a thermostat, what you have stated above is just wrong. coolant can never "flow to fast to cool". improved coolant flow ALWAYS improves cooling. thats how it works. I wont get into a discussion as to why, as this thread is not about physics, but information can be found pretty easily with a little help from google if anyone is interested.

shoebox

Maybe no problems, but you lose efficiency with no thermostat (and no other modification to the pump). There is just no reason to take it out, IMO.

There are numerous passages that are under control of the LT1 thermostat. With no thermostat present, heated and cooled coolant are allowed to mix in the pump. Some of the heated coolant from the engine is sent right back into the engine. Some of the cooled coolant from the radiator goes back to the radiator and not to the engine. If not for the adequate capacity of the radiator, you would likely see temps slowly climb to the point of overheating (and that is just what has happened to people in very hot climates with no thermostat).

marshall93z

I didn't run it long. Just until I could get another thermostat.

johnny3986

If a car runs a little hotter than factory settings for an extended period of time, your dino oil will break down faster. That is just something to think about for the long-term.

94Camaro_Z_28

I just bought a 95LT1 a few weeks back, and I could not figure out why it was overheating constantly.....turned out there was thermostat in it. Replaced it and boom, she's runs perfect.

Bow94z

There was a typical SBC thermostat in your car or none at all, or stuck open??? way you worded it, doesnt sound right...

Jim D

I am not sure on the LT1 motor, but I have read that having no thermostat could cause you not to pass your emissions on a cold start as it would take too long for the motor to heat up and get out of the "warm up" phase....(which makes it run more fuel and make more emissions).

1 Nasty Bird

The problem isnt the coolant going through the motor too fast. Its the fact that its in then back out of the radiator so fast it doesnt have sufficient time to cool. Therefore it slowly overheats.

96camaroSS

You might want to reconsult your physics books. If you move a fluid, any fluid, at a rate that exceeds the rate of heat transfer. You end up losing the ability to transfer heat effectively.

If what you have said is true, then all heat exchangers would benefit by moving water/glycol solution/or steam through them as quickly as you can effectively pump them. It does not work that way.

Josh'95Z28conv

I dont know about the pumping to fast theory, but I know some engines will over heat because without the thermostat, the coolant will never go into the radiator. It will just cause it to recirculate through the engine, and overheat.