Engine oil temperature

Anybody have any PRINTED information on what ideal engine oil temperature is for a working engine or how much oil it takes to disapate the normal engine heat from say a 100 horse power engine

Conventional petro based engine oil will breakdown in the 350 to 375 range in a short time. Synthetics (of brand name suppliers can go 100 degrees higher) 300 degrees is a good place to stop. There is no way to even estimate the second question. Engineers choose the numbers, Amount of oil pan surface area, and the use of cooling jets directed to the underside of the pistons. Some engines may see 20 to 30% of total heat rejection, while others might see much less. Jim

I bought a non contact infrared thermometer, actually 2 of them, from HF and checking engine temps was one of my reasons. I had a '79 JD 4230, 100 PTO HP, with cab and ac. I was rolling 5x6 rounders one hot summer day and when I got home, took all of about 10 minutes and in road gear.....engine didn't have time to cool off, I got one and made some measurements. The pan measured around 275F in several spots. The exhaust manifold and all was around 575. Water and along the cylinder area was around 190 as I recall.

In all I was surprised that the oil wasn't hotter. I made similar measurements on air cooled lawn mowers and was surprised about that.....engines were around 20 hp some above some below.

So the oil isn't getting worked as hard as I originally assumed. Amazing how good a job the flywheel fan on an air cooled engine does.

Is this what you were looking for?

mack trucks red line engine oil temp at 250 deg. turns on malfuction light at 260 starts derate.

DUNNO where you are going with this, but (obviously) the cooler the better. I would HOPE any quality tractor engine in the 100 HP range would have an adequate engine oil cooler and keep the oil within a reasonable range of the 195º coolant temp.

For gosh sakes, the DEERE 4010's had engine oil coolers back in 1960!

On the other hand my Case-IH/David Brown 1494, from 1987, with 85 HP does NOT have an engine oil cooler, which I find quite strange.

The HP doesn't matter.
The oil needs to operate above 212F to boil the moisture off. and evaporate away any other light ends such as fuel that has made past the rings which would have contaminated the oil.
Oil deterioration is not linear but exponential with temperature.

I do believe I read somewhere [other than Buicks post below ] anything under 212 causes water[ not boiling out] which truns to sulpher and acids that eat bearings.

It was an article in HOT ROD magazine . Anything below 212 is bad.

Well, had a couple manuals handy...
Superior Diesel PTD 6cyl 81/2 x 101/2 240/720rpm---
Normal lube oil optg temp---125F
Max lube oil optg temp---140-160F
Water normal and max---140 and 165 (couldn't find any dates)...
Wauk-Heselman Gen'l Inst's (1952 reprint?? "Edition 15")(No HP/RPMs--engines from 221-2894 CID)
Has a section on selecting oil by oil temp and air temp; says two paramount criteria: oil temp in running engine and whether Class "A", "B" or "C" engine "...class determined by size, bearing clearances and RPMs, but no class specs listed...
Goes on to show table of four optg temp ranges: 140-160, 160-180, 180-200, 200-220 with viscocity numbers (ranging from 10W-50W)for those temp ranges for all three "classes"...
Says over 220 oil breaks down, should install oil cooler; under 140 sludges etc.
Wauk 195DLC/DLCA Optg Manual (1961)(No HP/RPM) lists temp ranges:---Below 150, 150-180, 180-220 and 220-240, viscosity ranged from 10W-40W. Comments sludging below 160, problems above 230 may be alleviated by additives. No mention of any engine "classes".
Sounds like newer engines, and oils, run hotter......
Heat dissipation, I would guess, would depend upon numerous individual variables...

No, but I don't think Oliver did back in the days of the 310 Turbo charged engines either.... 8 quarts on a engine pushing 105HP or more? Not enough....

Donovan from Wisconsin

I drive two different Mack dump trucks occasionally. They run around 220 usually on a hot day and the cooling fan comes on only very rarely.

The primary issue to avoid in liquid cooled engines . Is avoiding significant nucleate boiling, steam pockets or voids where the inside of the cooling jacket is exposed to steam instead of water .

How hot does a liquid cooled engine operate with 1/8" of scale and oily crud insulating the engine casting from the coolant. While the operator blissfully looks at a 190F coolant gauge . As the paint burns off the head and top of the block.
A 50/50 coolant mix at 15psi, no oil mixed with the coolant and a temperature gauge reading of 240F would have a "cooler" engine .

(quoted from post at 00:11:02 08/21/15)

On the other hand my Case-IH/David Brown 1494, from 1987, with 85 HP does NOT have an engine oil cooler, which I find quite strange.

Click to expand...

If it is like my 1494, oil pressure goes to crap once it gets hot. Next time I have the loader off it is getting a cooler installed.

FWIW, some 1494s had a cooler.