What is the typical relationship between Water temp and oil temp at steady state cruise? Same? Oil Higher? Water higher?

 

If I'm not mistaken, Oil Temp will always run higher than water temp.

 

Thanks, Cruzzin,
Any idea how much higher - 10%?, 20%?

 

When you're fully warmed up, the temperature of the oil and water should be pretty close to each other. But yeah, generally oil will be a bit hotter than coolant.

Assuming your radiator is working effectively, water/coolant temp is just controlled by your thermostat opening temp, so say 90-odd degrees Celsius (sorry, don't do fahrenhiet, I'm English )

Oil temp will be up in the 90's too, but it depends where in the circuit you're looking. At high speed, fully warm, you might well see 110 degrees C in the bearings. The oil gets a real beating inside the bearings. Any hotter than that and the oil life will shorten.

Although oil will normally end up hotter than coolant, the sump oil will probably take longer than the coolant to get to its "final" temp. At light load/moderate engine speed the oil can take ages to get up to max temp. So in normal driving and short trips your oil temp gauge might well show a cooler temp than the water, even though you might think the engine's completely "warm"..

At cruise, just to give a figure, water should match the thermostat temp and oil will be about 90-95 deg C.

 

So 95C is about 200F?

 

in my 61 w/350
185w vs 240 oil
w/oil cooler 185 vs 220

 

You can run a bigger temp diff between coolant and oil if you use block rock in your engine, filled up to the freeze plugs, most of the heat generated is in the head so you won't ruin the cooling.

 

What is block rock?
W.

 

Having done a bit of looking thru the books,

T(celsius) = {5/9}*{T(fahrernheit) - 32}
or
T(fahrenheit) = {9/5}*T(celsius) +32

So yep, 95C = 203F

 

Matt is pretty much correct: On my 350 water temp is anywhere from 185-190 degrees. Oil temp is normal: 215-220 & it can even get as high as 240 on a real hot day. I run 20W-50W for oil. Trans temperature around 160, maybe 200 on a real hot day idling. Trans temp should stay under 200. This is for a TH400. TH350 may run a little bit cooler.

 

I run both gauges on my vette and truck , both temps will run very close to each other at normal highway speeds .

G

 

Mechanical or electrical guages?