6Speeder

Simply not true. Pull the cover off a hot tub at 100-110 and watch the water vapors flow off. It's a function of partial pressures.

Phillip123

The thermostat and the pressure cap are the most usual culprits.

Higgs Boson

exactly. water does not have to boil to evaporate.

Bill Dearborn

OP, what was the intention of lowering the thermostat temp? Was the car running improperly with the stock thermostat? Based on your description of your driving habit/style you spent time and effort to put in a lower thermostat and are now dissatisfied with the consequences. The stock thermostat opens at a temperature around 16 degrees more so I don't see what benefit if any you got out of the change.

Bill

RpeterK

Now

Did I say evaporate NO I said boil and there is a difference. This has been something that has been pretty much a given as far back as I can remember. At 60 it a was back a ways. It also makes sense.

Higgs Boson

If you read more than just the first post, you will find that the OP was reading the oil temp gauge rather than the coolant temp gauge and is not dissatisfied with the results.

The only thing that is "dissatisfying" if you can even call it that, is the yellow line on the tach, which is not a mechanical indication of anything but a simple software programming that is artificial in nature and modern "add it because we can" technology. The yellow line doesn't "do" anything.

Bill Dearborn

Coolant drawbacks are probably negligible. However, the coolant temp affects a lot of other things in the engine including the oil temp.

Low oil temps increase engine wear.

Not sure why a DI engine needs higher temps than other engines but all Internal Combustion Carnot Cycle Engines are more efficient when operating at higher temperatures. You can get better combustion thus more power and higher mileage at higher temps. Metal engines are pretty much limited to temps below 600 deg C due to structural issues with the various metals used in the engine. That is one of the reasons there is research into ceramic engines. They can operate at higher temps than metal engines.

Bill

Higgs Boson

Not trying to argue. It makes sense to you, as you say, but I guess it doesn't make sense to me, 6Speeder, or others (based on talking about this before).

If you can explain why moisture in the oil needs to boil (which it won't at 212 anyways since it is not pure water by itself, but mixed with oil) and what you mean by specifically excluding evaporation as a valid means of reducing liquid by means of vaporization.

Scroll down to Water % in this link:
http://www.bobistheoilguy.com/engine-oil-analysis/
It has nothing to do with 212 (unless we are just talking about uniform oil viscosity ratings).

Higgs Boson

If you are installing a low temp thermostat into an otherwise stock/untuned application, you will most likely not get much benefit. But with regard to actually taking advantage of the lower coolant temps, you can get better combustion, more power and mileage by increasing spark lead, which will get you much more of all of those things without any of the drawbacks of a higher coolant/operating temp.

Even in stock form, the ECM does not run on the high octane table, even with 93 octane in the tank. A lower coolant temp (or more octane to a degree, like 95-98) will allow the ECM to utilize more spark timing. Even on 93 octane, the stock tune will knock and pull timing and reside somewhere between the High and Low timing maps.

With that said, I am pretty sure the OP has a supercharger and can benefit in multiple ways from lower operating temperature. After all, this is the Performance section of an enthusiast Corvette forum, not the Keep it Stock, Mods are Bad forum.

NoOne

The lower thermostat was to stop the fans running at full speed all the time after the super charger was installed.

The tuning was adjusted so the fans came on earlier and ran faster which meant most of the time they were running 70 percent + and extremely loud.

After the t-stat was installed the fans were adjusted back down and now barely come on.

It was not because the car was overheating, it was not. In fact it ran pretty much stock temps but I have a feeling the reason it was done was overall cooling capacity. If the fans were to be left lower I assume that the recovery point would be exceeded and the car would overheat.

This has only been an issue with its been 50 degrees out in the morning. The car does run cool, anything over 60mph and it will drop down to 170's.

Over 65 degree's it runs at 180-190.

It has been very cool here in Michigan and with morning traffic not a lot of opportunity to warm it up.

A hard run on an open spot of the road will put it right up into the 180's after 1/4 mile or so.

NoOne

I just checked and maybe there is something else wrong, I did put in a 180 degree T-stat, thought it was 170.

It will not hit 180 if the outside temp is below 60 degree's if the car is moving. Under 50mph it will continue to gain in temp but anything over that the car will lose temp unless I'm really driving it hard.

I guess it would depend on how much air gets under the hood to cool the engine.

6Speeder

Actually, you didn't say boil, you said "burn" off. It won't ever do that. I gave you the benefit of the doubt that you meant that the contaminants would be removed by heating the oil. That happens at far lower temps than the un-pressurized boiling point of pure water.