Low Oil Temp
 

How low is too low for safe oil temp. I added a oil temp gauge this year and found out my oil temp was only about 120 degrees. Water temp is 160 degrees. I swapped the Auto Meter gauges from water to oil, same temps, they use the same sender. I have a 496 stroker about 600HP. Filter pad has center valve removed, side valve plugged, canton racing filter adapter, 3x18 oil cooler, Hamburgers filter housing. After seeing the low temps I added a Canton racing oil thermostat, still have low temps. I ordered a laser IR handheld thermometer and will see if I can get more information from that. I am checking the temp on the inlet to the filter after the thermostat.

Recirculating pump or crossover ? Crossover I’m betting

Yep, crossover works well, water temps do not fluctuate. Oil temp is my problem, maybe a defective thermostat? Cannot get much help from Canton Racing, guess I am going to have to call them back again.

Is this idling on the trailer or in the water with a good load on the eng?
Idling on the trailer my oil temp never really comes up much. Once running on the water with a load, it comes up ~200 degs.

Good question. After running all day does not get over 120.

Getting readings from an external temp gun would definitely be the next step.

Where is the oil temp sensor mounted amongst all the aftermarket oil sys components? Is it possible that it's air-bound?
My experience is that liquid temp sensors don't read air temp very well.

Handheld temp gun just came in today, I will test it out over Labor Day weekend. Sensor is in a -12 AN gauge adapter attached to the filter housing coming from the thermostat assembly.

UPDATE, oil temp was not low. AN anodized aluminum fittings do not conduct and a ground is needed for the sensors. Handheld temp gauge shows pretty normal temps on the AN fittings, actual oil temp is probably a little higher. I will have the gauges working for the next water test.

Good find. Have run into that with snodized parts too.

I use a flat male spade connector hose clamped to sensor’s brass hex body, to attach a thin ground wire.

You an also try to find a two wire temp sendor that reads in exact ohms you need. On 2 wire senders, 1 wire is sense, other is ground.

I am going to use stainless washers and sandwich a ring terminal. Auto Meter senders all came with a 1 wire hookup. I will report back in a couple weeks after I run it on the water.

I don't know anybody that gets accurate oil temps with the sensor installed in the remote filter assembly.

And why is that?

I have a couple theories.
The sensor does not go in deep enough because of the adapter fitting that is needed and filter mount and the fitting actually acts a heat sync and cools the oil at that location.
The other is that the same oil (or air pocket) sits in the recessed area where the sensor and fitting are. Kind of like putting something in the bed of your truck close to the cab.

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OK I agree with that, I was of the same thought so I took the Brass adaptor and drilled the inside pocket as large as I could while leaving enough strength for securement thereby allowing for a fairly large oil bath around the sensor probe. I also horizontally mounted mine and feel I get adequate volume of fresh oil flow across the adapter.
It is a shame nobody makes an oil temp sending unit with a larger base size so the probe would be fully immersed in flowing oil.

Just some notes on oil temps. Don't be scared to run the oil temp up a little. Would like about 215 or 225 ish. A little higher not an issue. Burns water out better. Most engines run the oil too cool.

I just took the oil cooler off to try it because mine(MPI) ran 180 to 220 ish even in hot summer. Friend of mine's carbureted 502's run with no cooler and runs around 220 to 250 ish when running hard in hot summer. Thus trying mine without cooler. Cleanest motors i have ever seen have been run their lives with quite a bit hotter oil.

I called Shell Rotella today and their upper level tech department said their 15W40 oil can take 300 F for a typical summer's usage without any issues. Interesting talk.

Good luck with that

As i mentioned below, I removed the oil cooler since the oil has always run to cool. WOT was like 215/220, which is perfect but only at WOT..
I ran 4600 rpm for almost 10 minutes in hot weather. The oil was at 275 without the cooler.. Nice to know it didn't get way higher, and motor can live with that. I didn't check it at normal slower cruising speeds but expect it to be a lot lower. Hopefully 225 to 235 in hot summer..
I also expect it to come down a little when i richen the AF ratio up, as its running lean right now. .Running lean can have a big affect on oil temperatures.


If you look at the oil taken from a motor running the oil too cool, vs a motor with oil say 220 or higher, there's a BIG difference in the look of the oil. You can tell the colder running oil has a lot of moisture in it turning it a more brownish color(or very slightly milky) instead of a cleaner, just a pure dark look with the hotter oil.. I've sent oil samples off in the past when running the oil with the factory cooler setup, and sure enough, has a lot of moisture in it.

I finally stopped all the moisture getting back to the motor thru the exhaust as a result of exhaust Reversion, which was giving a lot of the moisture issues in the oil and on the exhaust valves. But still had brownish oil from too much moisture with the oil cooler. The oil looks much better without the cooler.

Good luck.

article from Engine Labs on oil temperatures
 

Below is an article i found from Engine Labs on auto engine oil temps..So what temperature can you run in your car/engine?

That is quite a loaded question and near impossible to answer without a lot of testing. We can give it our best shot, though. Most passenger cars are perfectly fine with oil temps up to 240-260 degrees F *utilizing the OEM recommended oil weight*, with some being designed to handle temps up to 315 Degrees F and higher! How can this be? Standard oil these days have flash temps well over 200 C (400 degrees F), and as long as there is sufficient oil pressure, the oil does not care what temperature it is at. That being said, utilizing an OEM engine and OEM clearances, we would suggest sticking to the OEM oil weight up to around (240-250 Deg. F). If it makes you feel safer, run a bit thicker oil but with thicker oil, comes increased engine wear at cooler temperatures and increased heat into the oil through more friction and less flow (flow and pressure are inverse, as you increase pressure, you decrease flow). Above this temperature, we would recommend increasing the hot temperature weight to ensure sufficient oil pressure. Due to each engine having different optimum operating conditions, we cannot recommend a pressure/RPM to shoot for.

https://www.enginelabs.com/tech-stor...ty%20breakdown.

UPDATE, water test went perfect. Thermostat cycled correctly and sent the oil to the cooler as needed. I have temp sensors in AN fittings coming out of the engine and going back. Also added a oil pressure gauge at the thermostat. Should burn off the contaminates in the oil now. Going to get another oil analysis and hopefully get good results. I have always been worried about the oil being too hot not too cold.

They are in AN gauge adapters. They worked perfect after I grounded the sensors.

Canton Racing used a 210 degree thermostat and seems to be working great. After running for about 5 or 10 minutes the oil comes up to temp and starts cycling through the cooler. Oil coming out of engine is about 230 or so. After cooler it drops to about 190 going back to engine. It seems the oil needs to be at least 210 to burn off contaminates.

I run Amsoil 15w-50 racing oil and Amsoil techs told me their oil can handle 300 degrees no problem. I have a small cooler and my oil runs 280 after running hard for any distance. My oil comes out clean and it's still hard to see on the dipstick, when I change it. There is a new oil spec now that requires oil to be run in a test engine at 300 degrees for an extended period and then the engine is tested for wear and the oil is tested for viscosity breakdown. Amsoil ran the test with their signature oil and when they shut down and tested everything there was almost no change in the oil and no visible wear. So they put the engine back together and put the oil back in and ran it a second time. The oil still passed the test after running double the hours. The lab techs at the testing firm couldn't believe it. I also ran into the grounding issue, you have to go easy on the thread sealer so you get a good ground. I put my sensor right where the oil enters the filter before it goes into the cooler. I double checked it with my temp gun and it's accurate. My oil in my tow vehicle barely hits the thermostat temp even when towing, but it stays there for hours so moisture isn't an issue.

I use Amsoil 15/40 Diesel/Marine oil. How many hours are you getting out of the racing oil? The tech guys recommended sticking with what I have been using. Have you ever gotten a oil analysis? I have done 5 this year with the new engine. Pretty sure the problem was with low oil temps. Just sent them another sample today.

I have never tested the oil. I change my oil when I winterize so I have fresh oil in the motor over winter. I may put 25-50 hours on my oil depending on the season. My oil comes out just a little darker than I put it in and oil pressure doesn't vary from old oil to new so I'm not getting any breakdown. To be honest, I have been tempted to run my oil 2 seasons when I've had a short season. I keep my boat in a heated garage so the temp doesn't vary 20 degrees from winter to summer. The only problem I have with condensation is in the summer when it's super humid out. My garage is so well insulated it doesn't get over 70 degrees even in the summer when it's in the 90's. When I open the garage door the warm humid air hits the boat and it's soaking wet. I have to pull it out and towel it off. I may put a de-humidifier in the garage in the summer to keep it dry. I do run the Donaldson P550832 filter which is much larger than stock and has a 20 micron rating.

TIL,
I agree on the two season thing. Motor will never know it - oil is a little more forgiving than we realize. I've seen oil run for 3/4 years with no issues. I have run two short seasons a couple times but typically change it in the fall.. 50-60 hours/season. Funny thing is boaters all seem to have any number of other mechanical or moisture related issues with I/O motors rather than normally just wearing out, or oil issues. Very seldom see a worn out motor.

BTW,
Your oil temps look to be where you'd want them. I just took off my oil coolers on my 502's to see what temps it will run. Was way to cool even in summer with the big oil coolers that came on these 502MPI's. Oil was brown, not just slightly blackish like you want it to be. We shall see.

Oil analysis came back better. Raising the oil temps above 210 degrees definitely helps the oil. Other than a random high reading of Boron everything looked normal.

Jeffsway,
That's good news. Most don't realize their oil is running too cool. If i recall correctly, GM stated many years ago that a lot of wear comes from microscopic "pitting" from corrosion due to acids and of course moisture. Little wear compared to other factors comes from the motors when its up to temp and running. And moisture certainly makes the corrosion situation worse. :You've done good with the oil temps.

I would stick with the 15-40 diesel oil. I use 15w40. After hundreds of hours on the 502 motors, really no signs of cylinder wear. I do like the feeling of using a really good oil, but experience says the 15w40 diesel is good enough. And because so much cheaper, even though price of oil would not even be an issue if it helps engine life. But its not necessary. I actually use a brand called Schaeffer 15w40 diesel oil. More than Rotella but less than Amsoil. Used it for 30 years now. I bet you would never know the difference even using Rotella.

I went back and forth with AMSOIL technical support and they said 20W50 ARO or 20W50 ZRF. I ended up using ZRF with good oil analysis results after each oil change. If you want more details as to why, let me know and I’ll probably bore the hell out of everyone.