Oil too cold? Motor Gods opinion?

[Old H2S]

1983 SC 3.2ss, 9.75:1, ported heads, M1,Weber's, GT3 oil pump, stock cooler, stock trombone cooler, 200PSI cranking pressure.

Just another 3.2ss build, 2 years old, driven hard as my daily beater..My problem is the
oil temp takes over an hour of driving to get to 140 degrees and most of the time even in the summer heat it will not get to the middle position on the gauge unless I let it idle for 45 minutes. Neil and Henry said the finial frontier is friction reduction so I DLC coated the moving parts. Charles Navarro made the cylinders and told me to use Driven Air Cooled oil as it will drop the temps by 10-20 degrees.

The big question: How cold is too cold? The old wives tail is it will hurt the main bearings long term. Did I go too far? Overkill is my middle name, I need to know if this is wearing out faster? My AFR's look good..engine is strong, gauge is accurate and matches the temp on the 123 dizzy app on my phone. Did I screw up?

[pemz0r]

If you are driving hard, I feel that's impossible. Do you have an IR temp gun? If not, get one, they are pretty cheap on Amazon. Point and Click on your Oil Filter and see what that temp reads and see if it correlates to your gauge. Maybe your sender and gauge don't like each other (not calibrated correctly).

[PeteKz]

Tom: I would suspect the gauge or sender reading inaccurately, or the thermostat being stuck open. I get into the correct temp range even on cold days.

[stownsen914]

As suggested, I’d suspect an incorrect readings and/or a thermostat that’s stuck open. It’s worth considering the possibility that both are happening. Even with an open thermostat, it should eventually warm up in warm weather when pushed.

Good idea to check the filter or the cooler with an IR gun. Either should give an idea of actual oil temp.

[Old H2S]

Yes I got an IR gun, I will give you a number tomorrow.
Youall did see my note that the temp on the 123 Dizzy app on my phone matches the dash gauge right?

[Old H2S]

Also I will check the thermostat but I have checked the pipes many times after a drive and the 'stat has not opened yet and the pipes are still cold.

[Old H2S]

More Data:
Sunny, cold, blustery day, 43F, wind North 25Kts., Klein Tools 1R1 IR gun, car idling in the sun.
Starting temps. Oil Filter. Trombone
49F 45F
5 min. 60F
10 min. 90F 49F
15 min. 111F 50F
20 min. 120F
25 min. 128F 50F
30 min. 136F

Then, 10 min through town at 25 MPH
10 min. 70 MPH, 3rd gear, 4500RPM 25Kts. head wind.
154F 47F
10 min. 60 MPH 3rd. gear 4000RPM 25Kts. tail wind.
10 min through town at 25 MPH
149F. trombone hot pipe 80F, cold pipe 60F

[stownsen914]

Interesting data. For starters, looks like you gauge is right (and also matches the 123 data). It looks like you drove a pretty long while to only get to ~150 degrees F, which is cooler than I'd expect, even on a cool day.

So that brings us to the thermostats. The trombone one looks like it must be functioning, because the trombone is cool with oil temp ~150 deg F. It would open at like ~180 deg. Your engine thermostat may be stuck open. You could try measuring temp at the engine mounted cooler to confirm (it's a bit harder to get to). There are also some threads about removing the engine theromstat and testing its function.

[pmax]

154F on a 43F day seems within reason to me.

If I recall, the filter didn't go beyond 180-190F even on a warm summer day.

[Old H2S]

OK ,I believe you, it might be good. But it seems low to me and takes hours to get higher blasting on I95. Shouldn't it be 190-200F to burn out water and blow by gasoline?
Maybe I will send a note to Lake Speed Jr. he made the oil..

[targa72e]

Sounds like a stuck open engine thermostat. Had one that was bad (was opening at about 130deg) and It took forever to get it warm when cool. This was on a engine that really should have had a front cooler. In summer with 85+ temps when driven for 45+ min it would get up to temp and eventually continue up to about 220+. These are with temps measured on the oil filter with temperature gun and in car gauge.

john

[jkkarrow]

If you are driving hard, I feel that's impossible.

[brighton911]

I had a similar issue on mine. As part of the diagnostics, I removed the engine thermostat and did the hot water test to check the opening temp and it was fine. I tried a used one a friend had, same issue, very slow to warm up and rarely above 160 F. Although it did fly in the face of logic, I went ahead and installed a new engine thermostat - problem solved !

[Old H2S]

Thank you all for the responses.
My core question has not been answered, how cold is too cold on oil temps to burn off contamination and does it lead to engine wear?
The thermostat may or may not be in spec, and replacement might not correct the problem because I went too far in trying to make a cold running engine..

[stownsen914]

A few considerations ...
Since the external cooling circuit isn't opening, ~150 deg F is the max temp in your oil circuit. Not sure how to quantify any possible damage this is causing, but it's worth noting that 911s were designed with operating temp of at least 180 deg.
High temp does of course encourage the evaporation of water from the oil. There isn't anything magic about reaching 210 deg F (boiling point of water). Evaporation increases with increasing temp, so something closer to 210 is preferable.
I think it's worth testing your engine cooler thermostat. If it's stuck open, it could cause the symptoms you are seeing. Keep in mind that if it is stuck open, cold oil is going into the engine mounted oil cooler under higher pressure (from the cold oil) than they are designed to take. This can cause leaks or failure of the cooler.

If it were me, I'd want to check that thermostat for correct function.

[Old H2S]

All true. Why I think the thermostat is ok but might be opening early is the data paragraph shows the numbers of the speed blast in 3rd gear with the oil filter at 154F and the trombone lines still at 46F so the thermostat still had not opened until sometime on the way back..

[stownsen914]

Agreed that the data suggests the trombone thermostat is not opening.

But the engine cooler thermostat - are you thinking the data suggests that one is also not opening?

[Old H2S]

I will put it up on the lift and get cooler numbers..

[jkkarrow]

Sounds good.

[snbush67]

Originally Posted by Old H2S

OK ,I believe you, it might be good. But it seems low to me and takes hours to get higher blasting on I95. Shouldn't it be 190-200F to burn out water and blow by gasoline?
Maybe I will send a note to Lake Speed Jr. he made the oil..

FFS Nancy, the left lane in 5th gear at 50mph drafting Winnebago’s is not blasting. Try getting the rpm’s over 3000.

It really sounds like your thermostat is opening too soon or perhaps it’s stuck open. They’re made with beeswax.

Yes, the water in the oil can sit on your main bearings and degrade the surface. I think it’s more likely on cars that don’t get driven often or are stored for winter or longer.

https://forums.pelicanparts.com/porsche-911-technical-forum/927332-how-external-oil-thermostat-works-illustration.html