E4RTH WORM JIM

I've been watching my oil sump temperatures and it ranges from 78'c to 95'c, depending on load/rpm.

I've got an 80'c thermostatic sandwich plate & 19 row cooler installed. I'm going to swop the internals for a 90'c as my temperatures seem abit low.

What is the ideal oil sump temperature?

I've read that it needs to get to 100'c to remove water vapour.....

Chuck S

Any reason to have an auxiliary engine oil cooler? Racing the car? Water boils at 212°F/100°C.

-- Chuck

E4RTH WORM JIM

Supercharged and doing trackdays in the car yes. Including Nurburgring in September

Chuck S

Oil temp will be at least coolant temperature. Typical temperature readings are AFTER any external cooler and I suspect yours are too. Oil in the engine is hot enough to vaporize any water in it.

-- Chuck

BuggyofMildDiscomfort

Generally aim for sump temps of 90-105c, most of your wear and friction modifiers don't work correctly until 85+c

E4RTH WORM JIM

I have a baffled and bossed sump with a fluid temperature sensor mounted reading the oil temp. It's been calibrated and double checked with a heat gun and surface temperature probe so I can confirm the readings are accurate.

Yeah, it's on long motor way drives to and from the track I'm worried about, as the sump oil temps drop to 77.5'c @70-90mph & light throttle.

I'll swop the oil stat in the sandwich plate this weekend

chrispayze

Subscribed! This is interesting stuff, as I'm recently supercharged (TTS Supersport) and want to get it back on track next year. The main thing I've been considering is an oil cooler, and I've currently got a temp sensor in the sump plug, so I'm interested in the temps other people see at various points over various types of operation.

Mike RT4

I personally thank that is spot on for the useage.

Where abouts is the sensor mounted? Don't forget that with the design of the sump, the walls are going to be the coolest part of the oil, especially at high speed / low load cruising. The sump is designed to provide additional cooling for the oil.

I would leave well alone.

My Cosworth used to have similar readings (assuming sensor in a boss on the sump wall) and sometimes if there was lots of COLD standing water around in winter, the sump oil temp would drop to the high 50s, low 60s. However, as soon as it got in traffic, it would exactly match water temps (87°C) as then the sump was not providing as much cooling effect as when moving. However, on track it would be around 115-120°C in heavy use (19 row oil cooler, plus the OE water cooled Mocal).

As long as it is regularly going back up to water temps when the speed comes back down, then I would not worry.

You may find that if you fit a higher rated thermostat, you will sort the motorway temps, but struggle to keep the track temps down.

chrispayze

I find with my sump plug sensor, it takes a long time to warm up with light use and never reaches much more than 70deg, but one full throttle sprint and it comes up to temperature. I think this is as much to do with oil flow as it is temperature.

With low revs, the oil pump isn't pumping the volume of oil as at high revs, thus the flowing through the sump is likely to be focussed on the area around the pickup, away from the sensor (especially as my sump is baffled). As soon as the flow increases, more oil flows, more mixing occurs and the temp rises to its realistic level.

E4RTH WORM JIM

My sensor is located a couple of inches away from the sump plug where my oil return line runs too from my SC.

It's mounted fairly low down so it's beneath the sump baffle. The sensor tip sticks out about 15mm into the oil pan and yes it's connected via a welded on boss.

I have my AEM ECU set up so the rad fans come on at 82'c to keep the coolant at 80'c so have a couple of options for adjustment.

Mmmm still unsure what's best now....