Sidenote - turbo drain plug readings are MUCH higher..

 

I have fittings welded close to the in/out of the cooler.

 

Not stock oil cooler I guess?

 

RX-7 cooler. Plus a lot of other small stuff to reduce the temp.

 

Duke & Patrick: Any pictures of those installations??

 

My father-in-law has a similar issue, but he just runs the stock oil cooler. Honestly, if your temperature is below coolant temperature, I would question the device used to measure temperature.

 

Geez Duke, do we really have to spell it out – we mean when you are out driving on the track, not sitting in the track parking lot watching!

BTW – measuring oil temps when ice racing doesn’t count either….

Hard to believe that your sauna temps are higher than your oil temps…

Just kidding….

 

What do you mean by "issue"?
My coolant tempereature is between 78-82 C, so oil temp at the track is around 10 C higher.

Sump readings at highway cruise are very low.

 

Haha, hopefully Olli can chime in as an expert witness of sauna temps

Oil sump temps never exceeded those temps even when tracking the car in 90 F.

 

That's it? That seems awfully cool.

 

I have a really hard time following you with "issue" and "that's it?".
Not sure if you're asking questions or expect more info regarding something

 

Sorry for the confusion. Your temperatures seem very, very low to me. Your oil temperature should not be below your coolant temperature. If your gauge reads that way, your gauge is probably off. I assumed your coolant temp would be closer to boiling than it is, since boiling, albeit localized, is what makes cooling so effective.

So when I made the first post about the "issue," I assumed your oil temperature reading was artificially low. If your coolant runs 20C/36F below boiling, then I guess your oil temperatures make sense, but as I said, that coolant temperature is surprisingly low.

 

I would also worry about moisture in the oil when running that low of temps. That is below the boiling point of water, and you might end up with internal corrosion.

Check your oil filler cap, and see if there is any milkshake. . . Same thing happens to cars that are used for short hops; not enough time to evaporate the moisture out of the case.

JBreckeen
88 951

 

Now it makes more sense
But as I said, my oil temps are not below coolant temps!
With a low temp coolant thermo switch and a low temp coolant thermostat cooling temps should not exceed ca 82 C if not heat soaked.

Even if the oil sump temps does not exceed 90 C the oil is certainly higher in some other locations of the engine though so water evaporation should not be a concern.

In an optimal world the temps should hover around the thermostat levels so I would say my temps are exactly where they should be. Given good flow, no heat soak etc.

 

Since I live and track in a hotter climate oil temps are a big concern to me. I now run an RX7 cooler with a custom end tank.

I used to measure the oil temps at the drain plug. When I had the motor out and oil pan off I drilled and tapped a hole for a temp sensor above the plug. I noticed a 10 degree F difference higher in the new location. My thoughts are the drain plug is in the air stream and thus a little cooler than actual. I used the same sensor and wiring so that variable is out.

Long ago I also insulated the space between the exhaust and the block. The main concern here is radiant heat transfer. In city driving I noticed a reduction of about 15 degrees F by using an assortment of insulating materials. I think the main area of concern is the headers to block and crossover under the oil pan. I use alumina (a ceramic) with foil backing on the outside to reduce the chance of oil soak.