dmaxcamss

Let's say I installed a 160º thermostat in my car. That means, when the water temperature reaches 160º, the thermostat opens to allow the coolant to circulate.

So that means that the thermostat will not close until it gets to below 160º.

I don't know what degree of thermostat comes in the car from the factory, but it runs a constant 194º unless I am pushing the car. It will then get into the low 200s.

So tell me how a lower temperature thermostat make the engine run cooler? All that it should simply do is open the thermostat sooner. If that's the case, why even run one in the first place unless you live in a cold place where you want the thermostat to stay close at a higher temperature so that the car warms up faster.

JJC5

You will need to program your fans to come on at a lower temp. If your are cruising at a moderate speed, the 160 will run 30 degrees cooler than the 190 provided the ambient air temp is cool enough, but in stop and go city driving, it'll heat up just like the 190 does unless you reprogram the fans. FYI: the stock t-stat is 190. You never want to run without a thermostat either. The condensation in the crankcase will not evaporate unless the temp gets high enough.

nwc6

The 160 is supposed to start opening at 160. The one I bought started at 162ish, and was fully open by 170 something, I don't remember..My coolant temps (and most here with a 160) runs about 178 driving at speeds above 25-30. I did have the fans tuned when the car was on a dyno so the max I have seen is 195. That was stuck on the freeway in 95 degree temps..
Since getting a bad thermostat a few years ago, I make it a habit of checking them before install..

lemonademan

I wonder at what temp. does the condensation burn off, or evaporate

JJC5

You'll here that it needs to boil and obviously that's 212. It really doesn't need to "boil" but anywhere above 180 for a while is good enough to dry out the crankcase. My airplane mechanic told me that it's best to get the oil temp to 180 for at least 30 minutes especially if it's been sitting for a time.

nwc6

I should add I have an oil cooler..Oil temps run 195-200 on hot days, normal driving. Oil temps of 220ish spirited driving have been seen on warm days..
Even in my diesel truck, oil temps run 10-15 degrees warmer than the coolant..

philip_g

180 will do 'er.

haljensen

Any temperature! 212° to boil BUT no temperature limit for evaporation

AirBusPilot

Colder running engines are less efficient from a thermodynamic standpoint. However, these engines have multiple nannies that interfere by retarding timing unless the engine is in a narrow temp range along with cooler IAT's (colder thermostats help in this regard). This is done because of the very high compression ratio. All must be ideal to get the ecm from interfering with making optimum power. If you tune out these protections then you run the risk of detonation on most pump gas if the engine is running more efficiently (a hotter engine versus a colder engine). Ideally, you'd run a very hot engine with a real cold air setup, the appropriate octane and without the ecm interfering to make max power.

If I end up having my engine tuned, I plan on still using the stock thermostat but having the fans control the temperature at around 200*F or a little less.

6Speeder

You got it right on ideals. However, GM put in a thermostat that STARTS to open at 187 but isn't FULLY open until 212 or so. So, what you will end up with is your fans running trying to cool the engine, while the thermostat is closing, trying to keep it running hot for emissions purposes. IMHO you'd be better off with an aftermarket thermostat that will be fully open at the temp you want to run.

USAF-Vette

To add to AirBusPilot, oil also needs to be hot in order to clean internals properly. A colder engine is more prone to creating more water, which mixes with oil, which then creates acids that attack metal on the internal parts. Also, you will see an increased amount of sludge. Fuel won't be able to burn off either.

Be careful of a 160* t-stat and early fan-on settings....you could have a very cold combustion chamber in the colder months.

Rick

AirBusPilot

The stock thermostat and radiator combo is capable of holding coolant temp at around 196*F with sufficient airflow at highway speeds. Not sure when the thermostat is fully open, but as long as the rad can hold that temp it probably doesn't matter as long as the stock fans are adjusted.

dmaxcamss

None of these answers really answer the question at hand.

wbear

The answer is a lower stat does not make an engine run cooler. The stat simply sets the minimum operating temp of the engine.

You already answered your own question as to why run a stat at all. It brings the engine up to operating temp as soon as possible which is important.

NormWild

Well the technical answer is yes, but not as much as one would think. The lowest setting on the fans I believe is around 190, so even though you could potentially run cooler you are limited by the fan settings. I have mine set to run constantly at speeds under 30 mph, and am consistently at 192-194 in normal driving conditions in the summer and I have seen a max of 199 at 95 degrees outside temp while sitting in traffic. I would suspect a 160 stat would drop these temps by 5-8 degrees.

LS1LT1

100%




That is all true when talking about an LSx motor that is running way too cool (150/140 degrees or colder etc.).
But if one were to put some water on their hand and then stick their hand into a pot of motor oil heated to a constant 170/180 degrees (and/or higher) I am quite sure that the water would burn off in a relatively short period of time.

davekp78

To answer the OP's question:
A thermostat regulates the engine's coolant temp by controlling the rate of coolant flow through the engine. A lower temp stat will begin to open at a lower temp, thus lowering the engine's operating temp IF the radiator has sufficient heat rejection capacity.
In the C-6 cars, there is sufficient capacity to maintain below 180 degrees at cruise. At low road speeds, there is less airflow and thus the coolant temp creeps up. (thus the need for a fan)
In heavy traffic, the temp rises until the rejection of heat by the radiator equals the heat supplied by the engine. This rise can be slowed, or halted under some conditions, by increasing airflow with the fan.
As has been said, and demonstrated by those who ACTUALLY HAVE A 160 STAT, the cruise temp will be about 180 degrees, but will rise as high as a car with an OEM stat in heavy traffic- it will just take longer to get there. Reprogramming the fans will slow the rise even more, or even lower the max temp under some conditions.

Rogers 07

The Thermostate does 3 basic things. 1)It regulates engine temp by its stated opening point.
2) It prevents overheating by slowing the coolant flow thru the system, allowing heat transfer from the engine to the coolant and from the coolant out thru the radiator. (if coolant flows to fast, heat transfer wont happen effectively)
3) It promotes faster warm ups which prevent the formation of condensation build ups in the engine

All that for only $12.00

AirBusPilot

You sure about that? When the thermostat is wide open you are getting max cooling. Same as if you had no thermostat. You will not get thermal runaway by not using a thermostat or having it wide open.

6Speeder

It's not the same as having no thermostat. The opening is less than taking it out. For circle track motors we used to run a restrictor (just a circle of sheet metal with a hole in the center) in place of the thermostat to control the flow and hence the temp.