Question on oil temperature

[bobcowan]

I spent the last couple of days in Estes Park, CO. Friday was a pretty nice day - sunshine, and in the mid 50's until the sun went ebhind the mountains. Then the temps dropped into the mid 40's. Yesterday was considerably colder up there. We went up Trial Ridge Road as far as we could, and then the road was closed due to snow - about 9,500' ASL. We were chased out of town by a snow storm. Once we got down out of the mountains, it was a very nice day again. Sunshine and low 60's.

Because of this conversation, I was wqatching oil and water temps closely, just to see what they would do.

My oil cooler is connected, but it has it's own electric pump, and cools oil in the pan. When the pump is off, there is no oil circulating through the cooler. Absolutly none; so it's like not having a cooler at all. I'm also using a 160* water thermostat. I like to keep the heads as cool as possibly, to limit detonation on hot days.

Water temp was a steady 160*. Driving through stop and go traffic in Denver and Boulder, it got as high as 185*. Oil temp was almost exactly the same. Because oil holds heat longer, it would take a few minutes longer to drop to 160* when we got going again. But then it stayed the same as water temp.

Last Aug, I was in Deadwood, SD, for Kool August Nights. We drove out to Wall one day, and it was about 100*. Driving down the highway at 80mph, water temp was right about 190*. Oil temp was a little higher; then I turned the oil cooler on, and it dropped to about 185*, and the water temp dropped to about 180*.