Oil Temp

[w-lewis]

What is a normal oil temp for a 351 with and without an oil cooler?

[olddog]

typical oil temp 210 F

Shouldn't be any colder than195 F as condensation will be a problem.
shouldn't be hotter than 220 F as it can cause the oil to break down sooner.

Personally, I would want my oil to get over 212 F, at least once in a while, to get the moisture out. Moisture also does bad things to the additives.

PS
The desired oil temp is a constant regardless of if you have an oil cooler or not. Oil coolers generally keep the oil to cold for everyday operation.

[w-lewis]

Thanks. My original gauge never worked, so now that I have one that does, I want to know what to look for.

[twobjshelbys]

Google says oil will be 10-20 higher than water:

Typical engine oil runs around 230°F–260°F (110°C–127°C) in gasoline engines, whereas coolant usually stays around 200°F–220°F.

I can speak from experience that the oil cooler will reduce oil temp to below water temp... Had I kept the car I would have put in a thermostat to take the oil cooler out of the system. In fact, for street driving just bypass it. Leave the cooler cuz it looks good.

[w-lewis]

I'd like to disconnect my oil cooler, but not prepared to take on that project so I've blocked it off with clear plastic.

[cycleguy55]

FWIW, I wouldn't run an oil cooler on the street without a thermostat to control oil temperatures.

[bobcowan]

As said above, in routine street driving, oil temp will be around 10-15* hotter than water temp. Oil is mostly heated by RPM's. Situations that require extended high RPM's will heat the oil more; like road racing.

Finding the optimal operating temp is difficult, and seems to be a big trade secret. From what I've been able to find, 200* seems to be about right. Which really means that unless you're road racing, you don't need a cooler.

Max temp depends on the type oil, and duration. Cheap wally-world oil can stand 250* for a short while. A true PAO synthetic can handle 250* all day long.

There is a common myth that water will not evaporate at temps <212*F (100*C). If that were true, your kitchen floor would never be dry. Water will evaporate at anything above ambient temp/humidity. The oil in your DD probably never see's 100*C. Do a UOA, and you won't find water. My diesel truck generally runs about 175* (coolant) or so; there's no water in the oil.