Question about GEN II engine oil cooler operation

[hemibeep]

Just wondering about the control of the engine oil cooler on non-ACR Gen II...
I know there is a difference in the ACR valve, but what is it?

Is standard oil cooler always "on" or does the valve act similar to a thermostat only allowing oil flow at a certain temp/pressure.?

Trying to sort through a old engine problem and wondering about oil control valve function...thanks

 

[GTS Bruce]

In a non acr I forget the pressure.But as the pressure drops the valve CLOSES like you were idiling or moving slowly to maxamize AC condensor function.The acr adaptor is supposed to be good for plus 10 psi and the most important part full flow all the time.IN other words you could be hammering the car,having a pick up stumble or problem,the oil pressure drops,the valve closes and you don't even get cooled oil. GTS Bruce

 

[Ron]

While GTS Bruce is correct in the concept of non-ACR filter adaptor function, in reality if you were to start a cold GTS and let it idle to operating temp, you'd find the oil cooler quite hot, meaning to me the oil pressure at which the valve closes is below even normal idle pressure.

ACR filter adapter is not recommended for cold temp usage as in theory the oil would never get to operating temp. The reason why I never upgraded.

 

[GTS Bruce]

Ok I looked it up in the service manual.In a non acr when the oil pressure drops to 30 PSI plus or minus 3 PSI oil bypasses the cooler.This does not sound like a happy situation to me.It could happen during a sustained corner etc.That's why I have an ACR adaptor,and after market baffles and windage tray installed in my car.I got mine from Jon B.Call it peace of mind or cheap insurance for an expensive motor.I had those installed before the car left the dealer. GTS Bruce

 

[hemibeep]

I am just wondering how the stock GEN II works....is it temperature or pressure? ?
I had some contaminated oil in cooler, thought it was clean, then the bad oil showed up AFTER 80 miles of driving..trying to figure out why it took so long to appear.

 

[Ron]

The GENII cooler definately is controlled via pressure not temp. GENI valves are temperature controlled which seems preferable to me. I'd guess they switched because of reliability concerns, cost and of course A/C performance at idle.

GTS Bruce. Why would bypassing the cooler be a bad thing in a high G corner? In fact as long as the pressure was above 30PSI, which it would be unless it was pulling air from the pan, the cooler would be in fact working. Conversely, if the oil valve was bypassing the cooler for some reason, it would be because the pressure dropped below 30PSI and any oil that was flowing would be headed directly to the bearings instead of to the cooler which would seem to be a good idea actually.

Agree completely about the benefit of the baffles but personally felt that using the m/y 2000+ deeper oil pan and improved windage tray was sufficient for my level of use, especially while under warranty as I was concerned about warranty coverage if I used non-OEM oiling components.