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.

[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...

[ssdurango]

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

[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?

[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]

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

[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.

[blowns10]

Very well put!.

[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.

[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?

[robertisaar]

there are SO many variables to that question... synthetic vs conventional, oil change intervals, the effect the filter has on temps/flow as it ages, what kind of filtering material it has and what temps it breaks down at, what rate it breaks down at... and that's just oil, then factor in coolant.....

that's a headache waiting to happen.

honestly, i wouldn't want oil temps any higher than the absolute minimum to burn off crap that gets stuck in the oil. so figure ~215*F for oil temps. that's my recomendation. whatever coolant temp comes along with that, or allows for that, would be fine with me.

[Tbay99Venture]

Auntie Flo

"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.

I have to wonder if that reasoning gets started from some of the DIY books that say "the thermostat also regulates the flow and without it turbulance could form in the cooling passages and cause overheating". Hence the (incorrect?) logic that if the stock thermostat is there to restrict flow then there's an aftermarket version somewhere between stock and no-thermostat with high flow. (cue trumpet music)

[robertisaar]

i had a nice long post, but the page died when i tried to post it...

more or less:

http://www.elephantracing.com/techtopic/oiltemperature.htm

they try to keep between 180 and 210*F...

my opinion: the 210 represents the ability to burn off the contaminants and crap that will result from normal and abnormal engine usage while still giving a proper amount of lubrication. the 180 represents the lowest temperature the oil can do it's job without becoming a drag on the engine.

now, i say you could shoot for 180* temps all the time... as long as you change your oil more often(since contaminants will continue to build and destroy the lubricative properties of the oil if it never reaches a temp to do so).

otherwise, i'd shoot for the more realistic range of ~210-215*F.

[Schmieder]

i had a nice long post, but the page died when i tried to post it...

more or less:

http://www.elephantracing.com/techtopic/oiltemperature.htm

they try to keep between 180 and 210*F...

my opinion: the 210 represents the ability to burn off the contaminants and crap that will result from normal and abnormal engine usage while still giving a proper amount of lubrication. the 180 represents the lowest temperature the oil can do it's job without becoming a drag on the engine.

now, i say you could shoot for 180* temps all the time... as long as you change your oil more often(since contaminants will continue to build and destroy the lubricative properties of the oil if it never reaches a temp to do so).

otherwise, i'd shoot for the more realistic range of ~210-215*F.

In such a case for the motor oil I feel I am at a good spot w/o the cooler hooked up. With out the cooler it averages 180* and hits around 210'ish when I dog it around. So in my situation using the oil cooler would not be a good idea.

But, I would like to have a valve where I can engage the oil cooler easily for situations like 1/4 mile track or really hot summer days in stand still traffic. Something with a switch in the cabin that controls the valve on/off routing the oil to the cooler or bypass the cooler.



I heard good things about 0W30 synthetic oils. But I also read 3100 engines with some miles, beyond 50k, would be better off with synthetic 10W30.

For now I use 5w30 as factory recommended.

Is there any truth to using 10w30 in higher mileages?

btw, Rob, what type of ride are you sporting? Just out of curiosity.

[robertisaar]

In such a case for the motor oil I feel I am at a good spot w/o the cooler hooked up. With out the cooler it averages 180* and hits around 210'ish when I dog it around. So in my situation using the oil cooler would not be a good idea.

But, I would like to have a valve where I can engage the oil cooler easily for situations like 1/4 mile track or really hot summer days in stand still traffic. Something with a switch in the cabin that controls the valve on/off routing the oil to the cooler or bypass the cooler.

I heard good things about 0W30 synthetic oils. But I also read 3100 engines with some miles, beyond 50k, would be better off with synthetic 10W30.

For now I use 5w30 as factory recommended.

Is there any truth to using 10w30 in higher mileages?

btw, Rob, what type of ride are you sporting? Just out of curiosity.

something like an electronically actuated blow-off valve.... but for oil. hmm... sounds like something the dry-sump crowd would use. as far as oil: that's your decision. i don't like using anything higher than a 5W, but that's just me and is a rather recent revelation. considering i have a 3.1GP and a 3100 MC at 175K and 184K resprectively, my system seems to work

EDIT: i wonder if a line-lock system would allow you to bypass the cooler in normal situations and then allow it when you want...

EDIT2: forget that. a line-lock will not work.