Can you run a car without a thermostat?

[83turbomon]

can you?

 

["Turbo-T"]

You can but you shouldn't.

 

[mikestertwo]

can you?

Not a good idea. You won't have any temp control on the motor. It will run too hot when the weather is warm and too cold when the weather is cool.

 

[machinegun]

Can you physically Yes.

Should you? heck no

The thermostat controls the flow of the coolant through the block heads and radiator. With no folow control your fluid would circulate through the cooling system at a much higher rate. This means that heat soak or the ability of the fluid to transfer thermal energy will be reduced. This will actually lead to higher combustion chamber temperatures and less heat transferred from the coolant at the radiator. It will make your cooling system much more ineficient.

Hope this helps.

 

[williambavila]

what is your car doing that would make you ask such a question?? there is a reason that you ask this correct?

 

[Little6pack]

beside motor issues it could have your trans fluid overheat and possible trans failure.

I know some trans fluid has to be a proper heat range.

 

[xxTurboTxx]

Mine didnt have one in it when I first got it,and it wasnt to noticeable in the warmer weather,but when late fall came around and it got cold, it wouldnt get warm enough to let the torque converter lock up..

 

[justcrusin']

Yes, you can.

With a street car the flow would be fast and would'nt be in the radiator long enough for cool down...This may make things worse in warm weather.

With two of my "track only" cars I leave it out. One car has nothing in it and the other has a large washer to restrict a little flow.

 

[Nick Micale]

Another take on this..........

......... With no flow control your fluid would circulate through the cooling system at a much higher rate. This means that heat soak or the ability of the fluid to transfer thermal energy will be reduced. This will actually lead to higher combustion chamber temperatures and less heat transferred from the coolant at the radiator. It will make your cooling system much more ineficient...

Our experience on T-R's has not shown this to be a problem, but just the reverse.

On race cars we certainly do not run antifreeze or thermostats. The higher flow rate will help cool critical areas like the heads, especially around the exhaust valves. Experiments with a protype high flow water pump from TA Performance also provided data to verify more cooling/flow to the heads gave a slight increase in HP.

It is also easier to maintain a consistent water/engine temp between rounds.

For many street GN's we have run them w/o a t'stat for many years and have found no problems. Granted, our freezing temps are very rare here.

Our day-to-day cooling situation is most likely more critical here than any metro area in the country, and we have NEVER found the water circulates or flows too fast through the radiator.

At 115 degrees, it WILL run cooler w/o a thermostat. :biggrin:

I do agree, if you are in an area of the country where the coolant temp will not reach a normal operating range w/o a t'stat, that is not good, and one should be used.

Like many questions posed here on the board, it is so broad and not defined so a specific answer is impossible without many qualifying criteria. :smile:

 

[Just a Six??]

Our experience on T-R's has not shown this to be a problem, but just the reverse.

On race cars we certainly do not run antifreeze or thermostats. The higher flow rate will help cool critical areas like the heads, especially around the exhaust valves. Experiments with a protype high flow water pump from TA Performance also provided data to verify more cooling/flow to the heads gave a slight increase in HP.

It is also easier to maintain a consistent water/engine temp between rounds.

For many street GN's we have run them w/o a t'stat for many years and have found no problems. Granted, our freezing temps are very rare here.

Our day-to-day cooling situation is most likely more critical here than any metro area in the country, and we have NEVER found the water circulates or flows too fast through the radiator.

At 115 degrees, it WILL run cooler w/o a thermostat. :biggrin:

I do agree, if you are in an area of the country where the coolant temp will not reach a normal operating range w/o a t'stat, that is not good, and one should be used.

Like many questions posed here on the board, it is so broad and not defined so a specific answer is impossible without many qualifying criteria. :smile:

Back in 91-92 I never ran one & raced every weekend. I had a quick cool down valve for after each run. Im drove it home & did some city driving without any issues?

 

[machinegun]

I like good conversation

Personally from my experience and limited testing I have found that no thermostat in an engine seems to create more hot spots then one with a thermostat.

I would agree that there are many contributing factors, ambient temp, engine / head materials type of coolant.

My personal experience has been though that if the coolant flies by the engine and radiator surfaces that it does not transfer the thermal energy as efficient. Basically what I am saying is it does not stick around long enough to absorb heat from surfaces such as the engine block or heads and transfer the heat to the radiator for disipation as efficiently.

If you have some testing information I would really like to look at it. My testing with a simple infrared gun and shooting areas of the block and heads we saw temp differences of 5 -7 degrees. Grant you this is not much but I would think that anytime you can reduce hot spots cant be bad.

Let me know what you think.

 

[Chris Hogeland]

Thermostat

Our experience on T-R's has not shown this to be a problem, but just the reverse.

On race cars we certainly do not run antifreeze or thermostats. The higher flow rate will help cool critical areas like the heads, especially around the exhaust valves. Experiments with a protype high flow water pump from TA Performance also provided data to verify more cooling/flow to the heads gave a slight increase in HP.

It is also easier to maintain a consistent water/engine temp between rounds.

For many street GN's we have run them w/o a t'stat for many years and have found no problems. Granted, our freezing temps are very rare here.

Our day-to-day cooling situation is most likely more critical here than any metro area in the country, and we have NEVER found the water circulates or flows too fast through the radiator.

At 115 degrees, it WILL run cooler w/o a thermostat. :biggrin:

I do agree, if you are in an area of the country where the coolant temp will not reach a normal operating range w/o a t'stat, that is not good, and one should be used.

Like many questions posed here on the board, it is so broad and not defined so a specific answer is impossible without many qualifying criteria. :smile:

Like Nick said I never use them in mine or my Customer Engine I build

 

[ThikStik]

Ive always considered it a big no no as it accelerates ring wear , and other parts. Ive experienced some cars burning oil for no apparent reason with otherwise great maintenance. Ifound them to have stuck open stats, probably for years. Even if engine gets up to temp, it spends too much time getting there with no stat. Bad for mpg too. I read along time ago that wear can be 2X as much on a cold engine ....probably below the 160 range. And it is a golden rule of longevity to never whack on a cold motor. Other parts of car need to warm up too, almost like humans.

 

[mikestertwo]

I agree with the above. Remember, the original post lives in Tacoma, Washington

 

[dr_frankenstein]

was 107* over here not to long ago....

I run a T-stat..... granted it maybe a 160* but I do always drill a 3/32 hole or two in the unit as well. never had a problem climbing the san augustine pass at 4500 rpm to and from work, on a 19x18 radiator.

A.j.

 

[davidf]

How can running no stat hurt MPG's? It usually gets around 98 in the summer here. I'd love to pull the stat but don't want to screw my drivability or mpg's. Thanks.

 

[charlief1]

How can running no stat hurt MPG's? It usually gets around 98 in the summer here. I'd love to pull the stat but don't want to screw my drivability or mpg's. Thanks.

A higher temp will make for a more effecent engine David. Up to boiling temps of course.:biggrin: You're south of me and it gets much warmer here on average.

 

[ThikStik]

How can running no stat hurt MPG's? It usually gets around 98 in the summer here. I'd love to pull the stat but don't want to screw my drivability or mpg's. Thanks.

2 things on mpg-You want engine to get up to temp fast...better burn/closed loop. And , better burn period because of atomization of fuel droplets...not as big of a deal with dry manifold/efi. Big deal on carb cars.