Oil Temperature?

[ACHiPo]

I have a 470ci BBM FE in a Cobra replica.  I have Smith's gauges, and the oil temp doesn't come up to temp the way I think it should.  The car has an oil cooler, but even with it taped off, the oil temp reads around 40C after 20 min or so.  I've seen it as high as 60C, but I'd expect the oil temp to be at least as high as the water at steady state (the water gets to 80 and stays between 80 and 90C during operation).  The oil temp gauge is mechanical.  I'm wondering if it is a calibration issue, or if the oil is really only getting up to 40C?

What suggestions do you all have?

[67428GT500]

Are you Canadian? U.S. gauges don't read in centigrade. My Shelby holds seven quarts of oil. Even when it's 100 degrees here it stays at about 175 ( 80C)  degrees. When it's about 50 degrees out I run more about 120 degrees. ( 50C)

                                                                   -Keith

[blykins]

I'd bypass the oil cooler altogether.  I haven't seen a Cobra yet that really needs one.   I've got engines in Cobras in California and Texas and they're not needed, even there. 

Keith, Cobras were based on cars made in the UK.....Smiths gauges are in Celsius.

[67428GT500]

I know about Smith Gauges. Most U.S. versions are in PSI and Fahrenheit. I'm well aware of where Cobras were made.  ( Real ones)

[Gaugster]

Any oil temperature below the boiling point of water is a concern. However the temperature at the sensing  unit can be 30 or 40F less than deeper in the block. A  second measurement device even temporary can help with calibration .

[ACHiPo]

Any oil temperature below the boiling point of water is a concern. However the temperature at the sensing  unit can be 30 or 40F less than deeper in the block. A  second measurement device even temporary can help with calibration .

Gaugster,
Thanks.  That's kinda what I suspect--the measurement bulb is not in the right place or the bourdon tube is out of cal.

'67,
My Smiths temp gauges came marked in centigrade and pressure is in psi and speedo is mph. I admit while I did unnatural things to get the correct fuel gauge in my replica, I did not pay any attention to the units on the gauges.

[ACHiPo]

I'd bypass the oil cooler altogether.  I haven't seen a Cobra yet that really needs one.   I've got engines in Cobras in California and Texas and they're not needed, even there. 

Keith, Cobras were based on cars made in the UK.....Smiths gauges are in Celsius.

Brent,
Disconnecting the oil cooler is a possibility.  I suspect, however, that most of my issue is calibration/correlation between the oil temp and water temp since I don't see any difference in oil temp with the oil cooler masked off.

Thanks,
Evan

[C6AE]

Any oil temperature below the boiling point of water is a concern. However the temperature at the sensing  unit can be 30 or 40F less than deeper in the block. A  second measurement device even temporary can help with calibration .

Why so hot?

[Joe-JDC]

There is horsepower in hot oil.  Joe-JDC

[cjshaker]

Not to mention evaporating off condensation in the engine and any water that makes it's way in to the pan (under the right circumstances, condensation can get thick enough to run droplets of water down into the pan).

[ACHiPo]

Not to mention evaporating off condensation in the engine and any water that makes it's way in to the pan (under the right circumstances, condensation can get thick enough to run droplets of water down into the pan).

That's my primary concern--I want to drive off the water.  I suspect I am as my oil looks and feels good, but the fact that the temp is reading relatively cold makes me wonder.

Evan

[Gaugster]

The pressure gauge can give you some indication of when the oil is nice and hot. Not a number though. With the exception of the high volume or high pressure pumps it is usually easy to note the idle oil pressure will reduce as the engine comes up to temperature.

+1 to Joe-JDC and Cjshaker. They were on point as usual.

[Drew Pojedinec]

Non contact thermometer IR gun’s are great for this. Quick verification of gauge function.

[ACHiPo]

The pressure gauge can give you some indication of when the oil is nice and hot. Not a number though. With the exception of the high volume or high pressure pumps it is usually easy to note the idle oil pressure will reduce as the engine comes up to temperature.

+1 to Joe-JDC and Cjshaker. They were on point as usual.

My oil pressure gauge acts normal once the temp gets up to 40C, which is one reason I suspect my oil temperature gauge is inaccurate.  The oil pressure when cold is ~70 psi and doesn't change much with RPM (I am running 15W40 and keep the revs below 3k until the water temp gets up to 80C).  Once the oil temp gauge moves off the peg, the oil pressure rises and falls with RPM as expected, dropping down to ~28 psi at idle when the oil temp gets to 40C.

[ACHiPo]

Non contact thermometer IR gun’s are great for this. Quick verification of gauge function.

That's a good idea.  I was also thinking of sticking a thermocouple down the dipstick tube once the engine was hot and after I turn it off.