Hey all, I know these Vette's have a pretty high temp thermostat in them. What temp are all you guys running to keep her a little cooler and get some more power out of her.

 

160-180

 

The thermostat is for the minimum operating temp, it will not keep the car running cooler. That would be a function of the radiator, airflow, coolant mixture, etc.

 

Alright thank you. Is there any benifit to staying closer towards either end of that spectrum? Any Pros/Cons at 160* then 180*

 

Many people say the 160 isnt hot enough to permit contaminants in the oil to boil off. Nevertheless I have run a 160 for about 20 years.

 

Ok Thanks for the help. Is there any specific brand of coolant best suited for this car?

 

green

 

I run a 160....

corvettes do not run a higher degree thermostat.. all chevrolet are the same

 

None of which ever used a 160.............

 

Ok Thanks for the help guys.

 

All Chevy V8 engines had 180* thermostats, until the EPA got involved with reducing their emissions. Then, GM went to 195* stats, because a warmer engine tended to burn off more waste hydrocarbons. So, if you are 'Green' and do not have any problems overheating, run a 195*; if not, run a 180* stat. Some folks run a 160* stat, which is not a problem for the engine, and does take a bit longer time to reach it's equilibrium running temperature...but that lower stat will not change that final running temp--just the time to reach it.

The 1981 & 1982 C3's had computer-controlled engine management systems. They may need a 195* stat for the system to operate properly (must reach temp above 180 or higher for the ECM to switch to open-loop operating mode).

 

I don't believe the issue with running a 160 thermostat is with contaminants. But a higher operating temperature will result in the burning off of more hydrocarbons, and thus better emissions. And a 160 thermostat may not get the oil temperature up to 212 degrees, the temperature it needs to get to to remove the moisture from the oil.

The main reason I'm against using lower temperature thermostats, is cylinder wear. I read an article once on cylinder wear, and it stated that around 90% of wear came from startup, and an additional 10% came after startup, and before the engine reached operating temperature. It showed that there was almost no cylinder wear after the engine reached operating temperature. A lower temperature thermostat is not going to lower the operating temperature, it's going to lenghten the time it takes to get to it.

Modern cars use 195 degree thermostats. 195 is not overheating, and at that temperature your engine will experience less engine wear, and burn off more emissions. That is why I run a 195 thermostat, and I live in Austin, where the typical summer day is over 100 degrees, and I don't have any issues with overheating.

 

A lower temp thermostat WILL NOT prevent the engine from reaching its "normal operating temperature"....unless you have installed too much cooling capacity for your engine.

 

But, it will increase the amount of time it takes to reach the engines operating temperature, and thereby increase the amount of time that the engine experiences greater cylinder wear.

 

That's not accurate either-
The engine will warm up at the same rate, regardless of thermostat.
The only difference is the target temperature the thermostat is trying to regulate the coolant at.
A 160 will heat up at the same rate as a 195 thermostat (up until 160, of course).

Elm

 

So it's fare to say 180 stat is the way to go?
Peace
Frank

 

I would say you can't go wrong with 180 on a non-computer controlled engine.
Elm

 

That appears to me to be a contradictory statement. "Rate" is the speed at which a variable changes over a specific period of time. Therefore a period of time must be given to know a given rate. If the period of time is to when the engine reaches 160 degrees, then of course the 'rate' is the same regardless of what thermostat is used. But if the period of time is to when the engine reaches it's upper operating range, where engine wear is minimized, then the 'rate' will be increased for the higher temperature thermostat.

The operating temperature of an engine is a range. The lower end of the range is set by the thermostat, and the upper end is set by the cooling system.

The designed purpose of the thermostat is to get the engine temperature into this range, and above the bottom end as quickly as possible by restricting the flow of coolant through the cooling system until the coolant has entered the desired range.

Cylinder wear has been shown to be at 160 degrees to be twice that encountered at 180 degrees. Therefore it is desirable to set the lower end of the operating range, via the thermostat, to at least 180 degrees.

The upper end of operating range will not be changed, be the lower the bottom end is, the sooner the cooling system is engaged, and the longer it will take to get to the desired upper end of the operating temperature range.

 

I've had both a 160* stat and a 180* stat in my SB '71 engine. And, it has operated in the heat of AZ and the moderate temps of TN. It does take somewhat longer for the engine to reach it's natural operating temperature with a 160* stat. And, I would say that time is a significant amount of time (several minutes)...even in AZ. After those "several minutes", however, the final op temperature is the same with either stat.

Needless to say, that in AZ, I opted to keep the 160* stat in the engine.

P.S. That is a very interesting chart. Notice that for "performance", the engine should run cooler. For least wear, it should run a bit warmer. However, the difference in wear rates...once above 160*F...is miniscule, at best. The greatest wear is when the engine is COLD (like winter warm up's)--50*F and colder is not good for the engine. But, I bet that chart curve is drastically different with full synthetic oil in the engine. It flows better when cold and has much better lubricity and film strength than organic (dino) oil when cold.

 

I think where part of the confusion (at least for me) lies is what is the true definition of "operating temperature"?

To me, coolant temperature is just that, coolant temperature. You also have oil temperature (which for me is just as, if not more important than coolant temp), exhaust temperature and combustion temperature.
What constitutes "operating temperature"? Is it simply coolant temp and nothing else?

If everything were perfect, the 'low' and 'upper' range of the cooling system should be equal- If you have a 160 or 180 thermostat with an adequately designed cooling system, the coolant should really never exceed the temperature set by the thermostat.

Cylinder wear at cooler temperatures is a function of several things- Cold engine parts will tend to fit 'looser' than when warmed up, contributing to wear. Oil is also colder and tends to flow more slowly upon start-up (not to mention the time it takes for full pressure to develop), contributing to wear.
I'm not sure you can just make a blanket statement that running a 160 thermostat will wear your engine faster than a 180? But I've been wrong before. That's why I like this this forum, I'm always learning.

I don't claim to be an expert at thermodynamics, I'm only going by personal experience.
But I'm always willing to learn!