xupkid2

Just installed a new oil cooler as I felt like my oil temps were getting a bit to high, 240deg in a 944 Turbo Cup. I run Valvoline VR1 20/50 and am wondering what temp it breaks down at. Not trying to get into the science of the oil or details, just an idea of where I need to be concerned.

Thanks
Brian

924RACR

I think in general I'd be concerned at 235...

I also run VR1, in my ITB 924 (though it's getting hard to find locally!!!)

Be sure to also take care in locating the new cooler, for proper airflow in and out...

Eric_Oz_S2

Wow, that seems pretty cool to me 240F = 116C. My oil temps are regularly around 130C=267F on the track. If your concerned, then maybe I need to be concerned?

ProCoach

Eric, you do not need to be concerned. While I think 267 F is on the upper end of the nominal band (280 is back off/fix it time), 225-240 is the desirable range, IMO.

Van

Can oil be too cold? It's 190-200F on my car. (It used to be in the 240-250 range until I put a big honkin' oil cooler on.)

ProCoach

Yes, it can. That's why many pro cars have thermostats built in.

The best engine builders (or the data driven ones) note and recommend a range of desirable temperatures and back that up with determining at what range the engine produces the most power. My race engine builder specifically says that my engine runs better and produces more power with 180-195 degrees water temp, 220-230 degrees oil temp and that I should not run cooler than 200 degrees oil temp. I pay him a lot of money so I do what he says!

That said, on the 944 and 951 models, I think beyond a certain point, high oil temp could aggravate possible volume starvation at the rod bearing journals, a known weak point and regular service item.

xupkid2

Would there be a temp difference between a synthetic oil and a traditional oil? ie: Mobil 1 vs VR1? My oil temps were previously running around 245-250 which I felt was high so now I have a giant oil cooler and am hoping it can get me down to 220-230

nabfa1

Just curious ….

So if on an occasion ( 1 to 3 times ) you reached 248F ( not for prolonged time - ie no more hen 10 minutes ) before fixing your oil cooler ( which I did ) - would you change your oil again ( if you just did it ) or would you think you’d be ok for the rest of the season or 3–>4000 miles ( VR1 Non synthetic 20w50 ) .

Thanks !

Matt Romanowski

Saying an oil temp doesn't mean much without knowing where it is being measured. Seeing 267 F in a sump is pretty high but coming out of motor it's not bad. On the cold side of the cooler and it's way too hot! As a reference, after talking and working on oil analysis with an oil company engineer, we said 300F out of the motor and 255F in the tank was the limits.

Yes, it substantially matters on the brand and base stocks. There is a huge difference in synthetic and traditional oil.

stownsen914

Looks like we've bumped a pretty old there here, but a couple thoughts:
- Personally I wouldn't be happy running dino oil higher than 250 degrees measured cool side as a max. I'd prefer lower.
- Different engines have different tolerance for temperature. Water cooled motors are generally more tolerant. I hear modern Porsches regularly run hotter than that and people don't seem too concerned. Aircooled, different story. No way I'd be running a 911 regularly at 250+ oil temp, even with good synthetic oil - the top end would run too hot.

Ubermensch

This fellow seems to suggest thermal breakdown for that oil begins at 285F (MOTOR OIL ENGINEERING TEST DATA | 540 RAT - Tech Facts, NOT Myths (wordpress.com)). So, to Matt's point, depending on where you measure the temperature and the relative difference at a bearing surface, you may want to keep things much cooler than that.

bgiere

No problem for Valvoline VR1 or any well blended modern oil actually.