[Former_Boosted_IS]

Originally Posted by Joshboody

good point, with the stett plate it looks like the bypass is eliminated. I wonder how this effects flow and filtering in colder temps.

The oil still flows, but it bypasses now at the thermostat and re-circulates until the thermostat opens.

[Joshboody]

Originally Posted by Mr. 5

How can this be?
Maybe we're using differen vocabulary.
Look at the picture below.
In the picture the thermostat is closed. You can see the diaphragm closed on the right.
When the oil heats up then the diaphragm will move to the left (of the pic) and let the oil pass through to the OC.

Any conclusions here? I still think the t-stat closes the return and when temp increases the t-stat moves to the drivers side opening the return and closing the bypass.

Originally Posted by Former_Boosted_IS

The oil still flows, but it bypasses now at the thermostat and re-circulates until the thermostat opens.

Yes, I see that now after reviewing your DIY.


An aftermarket company should produce a lower temp t-stat... 225deg would be nice. It would NOT replace the larger OCs when tracking, but would be nice to see lower temp in normal driving.

[black e]

Originally Posted by Joshboody

An aftermarket company should produce a lower temp t-stat... 225deg would be nice. It would NOT replace the larger OCs when tracking, but would be nice to see lower temp in normal driving.

that wound't make a big diference. i took the spring out from the thermostat and the oil temp is only 10~15* lower most of the time but when i really beat on the car the oil temp still shoots to 255*+......a bigger cooler is the way to go.

[MDORPHN]

Originally Posted by black e

that wound't make a big diference. i took the spring out from the thermostat and the oil temp is only 10~15* lower most of the time but when i really beat on the car the oil temp still shoots to 255*+......a bigger cooler is the way to go.

Make sense since simply installing a lower temp thermostat doesn't increase the thermal capacity of the system.

Neil

[Joshboody]

Originally Posted by black e

that wound't make a big diference. i took the spring out from the thermostat and the oil temp is only 10~15* lower most of the time but when i really beat on the car the oil temp still shoots to 255*+......a bigger cooler is the way to go.

Ok, I think I failed to understand completely. So taking only the t-stat spring out moves the plunger to the drivers side closing the bypass completely. BUT taking the t-stat out would leave the bypass open at all times.

[black e]

the spring is what keeps the t-stat closed so taking it out keeps the passage open.

[DesertDude]

So I asked STETT if they could give any more detail on how the oil cooler thermostat works. Here is their response:

"There is no bypass in the factory thermostat or the lines. The factory thermostat uses engine coolant temperature as well as oil temperature to actuate the thermostat which then allows oil flow to the oil cooler.

Our factory thermostat delete and adapter plate removes the factory thermostat altogether and allows you the option of running a high flow thermostat or not.

Thanks!
STETT Performance
"

Interesting that they specifically say there is no bypass, so it appears the diagrams we are looking at are not accurate. It is also interesting that they say both coolant temperature and oil temperature affect the actuation of the thermostat, which would explain why there is coolant being run to the thermostat housing.

[BrianMN]

Originally Posted by black e

that wound't make a big diference. i took the spring out from the thermostat and the oil temp is only 10~15* lower most of the time but when i really beat on the car the oil temp still shoots to 255*+......a bigger cooler is the way to go.

Can you tell us a bit more about your experience with taking the spring out?

What all did you remove from the thermostat housing?? I would have to assume you took the entire plunger out or it owuld just be loosely sliding in there?

[BrianMN]

Originally Posted by Former_Boosted_IS

BrianMN, that is awefully presumptive. I have never told anyone to buy a single product on the forum. I made the best choice for my needs and I suspect you will do the same.

Fluid dynamics and thermodynamics are not subjects I am a rookie to.

Personally I think this forum tends to over-analyze simple concepts sometimes. Oil coolers are not rocket science and have been used on hundreds of other cars. Based on the confirmation that coolant is going to the oil thermostat housing, I just think you are looking at BMWs way of warming the oil to a usable temp faster.

My apologies for that statement. I realize you have always been entirely neutral and unbiased in product discussions and write-ups.

But, if I were you and I just put in a very nice and complete Oil Cooler kit, the last thing I would do is agree with people simply taking apart their stock thermostat to replicate the cooling benefits of a real OC system.

The only thing Mr 5 and I are unsure of is the passageways inside the factory thermostat. Our goal is to discover a way to allow the oil to fully flow through the oil cooler at all times... and that is going to require in-person examination or experience with similar trials.

Cheers

[Mr. 5]

Originally Posted by BrianMN

My apologies for that statement. I realize you have always been entirely neutral and unbiased in product discussions and write-ups.

But, if I were you and I just put in a very nice and complete Oil Cooler kit, the last thing I would do is agree with people simply taking apart their stock thermostat to replicate the cooling benefits of a real OC system.

The only thing Mr 5 and I are unsure of is the passageways inside the factory thermostat. Our goal is to discover a way to allow the oil to fully flow through the oil cooler at all times... and that is going to require in-person examination or experience with similar trials.

Cheers

Whatever we can learn, the better.
I honestly started this thread to mainly ask the question about which lines were the flow and which were the return. I found out, but now the information grew to the Tstat and it's extremely interesting.

I just wish I would have had more time at the body shop and then I would have taken it apart and inspect it once it was off.

[Former_Boosted_IS]

Originally Posted by BrianMN

My apologies for that statement. I realize you have always been entirely neutral and unbiased in product discussions and write-ups.

But, if I were you and I just put in a very nice and complete Oil Cooler kit, the last thing I would do is agree with people simply taking apart their stock thermostat to replicate the cooling benefits of a real OC system.

The only thing Mr 5 and I are unsure of is the passageways inside the factory thermostat. Our goal is to discover a way to allow the oil to fully flow through the oil cooler at all times... and that is going to require in-person examination or experience with similar trials.

Cheers

Ahhh, I see now what you are trying to do. I still think the stock oil cooler is too small to be sufficient for this car. With that said, I do agree that no thermostat would be better than a thermostat at 240F.

[Mr. 5]

Originally Posted by Former_Boosted_IS

Ahhh, I see now what you are trying to do. I still think the stock oil cooler is too small to be sufficient for this car. With that said, I do agree that no thermostat would be better than a thermostat at 240F.

Do you know for a fact that it is at 240?
This doesn't make sense to me because my oil temp goes up to about 225 and stays there on my commute to work.
I still believe it's variable.

[Former_Boosted_IS]

Originally Posted by maxnix

Well, when it is near 30° F, it is more than adequate as the oil never gets about 180° F.

No thermostat means the condensate doesn't get boiled off, which means your engine lubrication is compromised to the extent there is condensate in it.

Honestly, I hear you guys repeating that constantly, but I have another performance car that never goes above 212F in the winter ever and it is not even close. I think you guys are making a mountain out of a mole hill. My other car has never had any lubrication issue whatsoever.

[Joshboody]

Originally Posted by Mr. 5

Do you know for a fact that it is at 240?
This doesn't make sense to me because my oil temp goes up to about 225 and stays there on my commute to work.
I still believe it's variable.

From my understanding this would mean the return is open and the bypass is open... the t-stat plunger has moved partly, but not fully open.

[Joshboody]

To summarize my conclusion on oil path and t-stat... please let me know if others have a different understanding.

- t-stat is variable and fully open at a specific temp.
- t-stat closed, bypass fully open and OC oil return is closed
- t-stat fully open, bypass closed with 100% oil flowing through OC
- removing the t-stat would cause the bypass and OC paths to be open so flow would be least resistance.
- removing the spring only would cause flow through OC

Not sure how much improvement could be seen from a lower temp t-stat, since temp is dependent on the OC efficiency. RealOEM stats 110 CEL for the t-stat which, if referring to t-stat temp, is 230degF. If this is the case, my car runs at consistent 240deg when fully warm, so this is the max efficiency of my OC. BUT if t-stat is 240deg, and I run at this temp steady, a lower temp t-stat may show some benefit. Taking out the t-stat spring should give some indication of your OC efficiency.

[Mr. 5]

Originally Posted by maxnix

Well, when it is near 30° F, it is more than adequate as the oil never gets about 180° F.

No thermostat means the condensate doesn't get boiled off, which means your engine lubrication is compromised to the extent there is condensate in it.

Originally Posted by Former_Boosted_IS

Honestly, I hear you guys repeating that constantly, but I have another performance car that never goes above 212F in the winter ever and it is not even close. I think you guys are making a mountain out of a mole hill. My other car has never had any lubrication issue whatsoever.

I'm trying to figure this out as well.
I'd like for the explanation of condensation because I don't get it.

Why does oil need to go higher than the boiling point of water before it goes through the oil cooler?
Are you saying that oil can't properly lubricate if it's less than the boiling point of water? I doubt it.

[black e]

Originally Posted by Former_Boosted_IS

Honestly, I hear you guys repeating that constantly, but I have another performance car that never goes above 212F in the winter ever and it is not even close. I think you guys are making a mountain out of a mole hill. My other car has never had any lubrication issue whatsoever.

+1

i've had multiple 6xx + HP cars and none of them had normal operating oil temps past 210F, stock or with built engines and lasted 75k miles +,...

[jzchen]

I'm sorry I haven't worked on this thread for a little bit. My car is still in pieces and my family is complaining about me messing with our expensive/new car. I found the possible reasons for keeping the temperature high in this article on the web:

http://www.vfis.us/

[BrianMN]

Originally Posted by Former_Boosted_IS

Ahhh, I see now what you are trying to do. I still think the stock oil cooler is too small to be sufficient for this car. With that said, I do agree that no thermostat would be better than a thermostat at 240F.

Yeah, the idea I'm having is getting the daily driving oil temp to go from 240 down to 220 or so, simply by removing the thermostat. You're right that when on the track the small oil cooler won't be enough to keep temps down...daily driving it should.

Originally Posted by maxnix

Well, when it is near 30° F, it is more than adequate as the oil never gets about 180° F.

No thermostat means the condensate doesn't get boiled off, which means your engine lubrication is compromised to the extent there is condensate in it.

In the summer, my daily driving oil temps are around 240.
In the winter (0* now) my daily driving temps are 220. Not sure why you're only seeing 180*...that's abnormally low

If we allow oil to constantly flow through the oil cooler, it will eventually reach 220* or more...just take longer to get there. We're sacrificing the quick warm-up for lower temps later.

The oil should always reach above 212 at the hot spots of the engine, boiling whatever condensation is present, so that shouldn't be such a concern.

[jzchen]

Originally Posted by Former_Boosted_IS

Honestly, I hear you guys repeating that constantly, but I have another performance car that never goes above 212F in the winter ever and it is not even close. I think you guys are making a mountain out of a mole hill. My other car has never had any lubrication issue whatsoever.

I think an important point to consider is whether or not you are going to tune or increase output of the engine. When you use a Stillen supercharger they tell you to put a one step cooler plug in. Over in the Cadillac forums those increasing boost in their CTS-Vs are putting cooler thermostats in, I believe 180 or even 160 degrees as a matter of fact. It may be good to consider also changing the coolant thermostat to a lower level, and the idea of lowering the thermostat for the oil cooler may be in line with this.....

Discussion on the 2nd generation CTS-V:

http://www.cadillacforums.com/forums...hermostat.html

[Turkeybaster115]

I just wanted to add that I have an '07 car, sans oil cooler, and I've noticed that after about 7,000 miles the oil I'm using starts to boil, and come out of the top of my oil filter housing in small spirts. I started getting the burning smell and recently noticed that it was were the smell was coming from. In case you were wondering, the oil I use is high quality Total quartz 0W30. Its a PAO based synthetic, and I usually run the oil for 8,500miles. The car still holds temp at 240, since I drive exclusively on the highway daily. I will be retrofitting an ar design oil cooler next month, in preparation for the summer racing season. I have an auto btw.

[Mr. 5]

Here's another picture of the oil cooler that I installed.