thermostat

[Schmieder]

Its amazing if you let a trans hit 230* oil temp people will shit a brick and at 240* damage is for sure, but at the same time people say engine oil temps need to be 220* or higher to burn off contaminates. Crazy with how one is so much more sensitive than the other.

I've been running a 180 thermo, But I do not know what my oil temperature has been so I can not say if the 180 thermo is hurting oil heatup, or keeping it right where I want it.

As some have said, the place where your getting the temp, and how/when the thermostat is open, it may not be removing enough heat to hurt the oil temps, and you may not want to let the coolant reach 220 or higher.

You really need to be monitoring both to know the true answer.

My ATF's operating temp is about 160*. After some boost it can go as high as 190* (thanks to my ATF cooler).

After learning a few things in this thread, I would understand why I should stick with the 195 t-stat. But having a turbo now it makes more sense to get a 180 and no lower, no 160* t-stat. I have a 180 t-stat atm.

Though now I will start to fine tune the coolant fans on/off to a higher heat range and judge the best spot to enforce.

My stock fans would come in stages, one before the other at diff temps. I think by narrowing the gap I can keep the coolant at a specific temp when being pushed. Sort of like having 180* coolant during normal driving but having a higher temp tuned in for the days I am running boost for fun.

So now the question I ponder is, what is the optimal coolant temp and oil temp for boost/performance operation. If higher temps increase efficiency then power output should be increased as well. Anyone have an idea? 220*, 200*? Then tuning the oil coolant to a specific temp I could run a bypass with adjustable valve to the oil cooler and adjust the valve to a desired flow to the cooler versus back to the pan. Basically increasing or decreasing oil temps with a valve.

Simplified, what is optimal temp for coolant and oil for performance?

[3400-95-Modified]

Its amazing if you let a trans hit 230* oil temp people will shit a brick and at 240* damage is for sure, but at the same time people say engine oil temps need to be 220* or higher to burn off contaminates. Crazy with how one is so much more sensitive than the other.

I've been running a 180 thermo, But I do not know what my oil temperature has been so I can not say if the 180 thermo is hurting oil heatup, or keeping it right where I want it.

As some have said, the place where your getting the temp, and how/when the thermostat is open, it may not be removing enough heat to hurt the oil temps, and you may not want to let the coolant reach 220 or higher.

You really need to be monitoring both to know the true answer.

[blowns10]

Very well put!.

[geoffinbc]

Yes water boils at 212*F but a coolant temp around 200*F is going to result in an oil temp of 215*F to 230*F and any condensation in the crankcase will boil off. If you run an oil cooler then the case may be different. But either way a temperature closer to boiling point will mean the water will evaporate faster. This is a bigger issue on short trip vehicles.

The point is keep the stock stat it is simply better than a cooler one for many reasons including power production and fuel economy which are the ones we care about most.

[Schmieder]

no dislike, just that's it's so mind-numbingly simple, it needs not be said. more or less, turbo center housing has a lot of heat added to it thanks to the turbine half of a turbo and all of the hot exhaust gases that interact with it.

"high flow" stat... it's probably a thermostat with part of it's frame removed to increase coolant flow maybe a few percent. a thermostat opens/closes based on the temp/pressure of the coolant on the engine half of it. if you "need" more flow, you're best getting a water pump that can push more.

EDIT: Sorry Rob for the not-so-nice post.

It was hot and humid yesterday and it wasn't the best day for me. I know I asked a silly question but thats me. I can be brilliantly gifted in one respect and dumb as a rock in another. If you knew me in person, you'de understand the workings of my mind, I am not a typical person.

end update

Sure the turbo heats up the oil but the two are heating and cooling hand in hand. Of course the two are being heated by different mechanisms of the engine but they still reflect each other.

In fact, the two mediums will always try to equalize temps through the block itself. As I understand it is best to have oil and coolant temps equal to each other. So questioning the temps relationship with each medium isn't too simple after all. A vehicle with a very effective coolant system will surely see cooler oil temps then a vehicle with an old and less effective coolant system.

Don't believe I am thick, I like to go into the science of such questions. When I have solid info to work with i can think on it and make things happen.

btw, I really appreciate all the help you provided me when I was building my turbo but if a question is so mind numbingly simple for you to answer just don't reply.

Thanks

[robertisaar]

no dislike, just that's it's so mind-numbingly simple, it needs not be said. more or less, turbo center housing has a lot of heat added to it thanks to the turbine half of a turbo and all of the hot exhaust gases that interact with it.

"high flow" stat... it's probably a thermostat with part of it's frame removed to increase coolant flow maybe a few percent. a thermostat opens/closes based on the temp/pressure of the coolant on the engine half of it. if you "need" more flow, you're best getting a water pump that can push more.

[Schmieder]

oil temp =/= coolant temp...

they do generally follow each other, but a turbo car WILL show a higher oil temp at all times compared to a N/A car in the same situation. i'm not going to explain why for fear of an anuerism.

and if you pay actual money for a "high flow" thermostat...

Yeah I know they don't follow temps exactly but surely the coolant has a big effect on oil temps. As coolant temps rise, so do oil temps.

Jegs sells the 'high flow' t-stats. I'm detecting your disliking for high flow t-stats. Is there a reason why? Am I missing something?

What do you mean, "fear of anuerism?" Am I detecting a disliking towards me?

[ssdurango]

I just read that a test engine has been run up to 300* F and performed very well.

[robertisaar]

moisture in the crankcase isn't under pressure at certain stages through the oiling system.

So letting a car reach 212* will vaporize crankcase moisture, I never thought about it but it makes a lot of sense. So the fans should not turn on until 225*?

Now the question I ask is it better to have a high flow t-stat versus regular flowing t-stat, regardless of temp.

oil temp =/= coolant temp...

they do generally follow each other, but a turbo car WILL show a higher oil temp at all times compared to a N/A car in the same situation. i'm not going to explain why for fear of an anuerism.

and if you pay actual money for a "high flow" thermostat...

[Schmieder]

moisture in the crankcase isn't under pressure at certain stages through the oiling system.

So letting a car reach 212* will vaporize crankcase moisture, I never thought about it but it makes a lot of sense. So the fans should not turn on until 225*?

Now the question I ask is it better to have a high flow t-stat versus regular flowing t-stat, regardless of temp.

[blowns10]

Yes, pure water boils @ 212 degrees Fahrenheit, correct. And adding coolant increases the boiling point, yes you are correct. I could write for days about this stuff and I would be glad if someone would make this topic a sticky!!. Yes the engine can be made to run as hot as possible for best emissions. But heat (friction) is also the enemy, so you have to have a safe margin to work with, otherwise whatever you are running, be it differential fluid, transmission fluid, engine oils, brake fluid needs to be kept as cool as possible to keep the component working properly and to prevent overheating and warping or seizure of the component!!. Like I said, enlighten me!!. Late.

[robertisaar]

Water boils at 212 degrees Fahrenheit, not 200 degrees.

Yes, definitely, this topic should be made into a sticky, enlighten me!!. Late.

if you want to get technical, PURE water boils at 212*F when not under pressure. pressure raises the boiling point significantly.

[blowns10]

Also consider that water boils at 200*F

Water boils at 212 degrees Fahrenheit, not 200 degrees.

Yes, definitely, this topic should be made into a sticky, enlighten me!!. Late.

[ssdurango]

My propane conversion manual says to use a cooler thermostat (160 or so). Propane is allready a vapor once it's been through the regulator so there is no need for more heat to completly burn it. In a boosted application, like mine, this can stave off pinging and detenation.

[sprucegagt]

Every few months this topic keeps coming up, and every few months the same responses keep coming. I wonder if this should be a sticky?