Is need of external oil cooler overblown

[ZDan]

Originally Posted by new2subaru

Oil pressure gauge is on the Xmas list. I'm curious now.

Yeah, that's a good idea, better if you can log it and see what it does during track events. Oil pressure can be an issue with these cars, but it's not temperature-related but rather oil-feed related, RTV blockage, drops during cornering (more an issue with '22+).

Been running the JRDOC for years, 40ish track says and no issues.

FWIW I did 50 track days (25 events with COMSCC) on my 2017 PP (and 82k street miles) with oil temperature going to just above 270F mark on the gauge every single session. Highest logged temp was 275F. Never any issues. Usually ran 5w30 but did a couple of events (4 track days) with Subaru 0w20.

In my mind heat causes wear and keeping things a bit cooler should help. I'm not saying that you have to have a cooler but that's just my thought process.
Knock on wood, another 12-15 tracks days next year.

Logging pressures will let you know if your getting big dips during cornering and I would think should also give an indication if there are any losses due to blockage or other.

Originally Posted by autoracer86

235f oil temp on track is pretty good I would say. Shouldn’t run into pressure issues at that temp.

Again, going higher in viscosity is going to do a better job of keeping oil pressure up at higher temps vs. going to an oil cooler.

275F indicated is reportedly 255F at the sump. This is just no big deal for any decent 30-weight synthetic, and if you want higher pressure than what that gives just run 40-weight. Honestly at 235F indicated I'd probably just run 0W20 street or track all year.

These cars have had engine failures with and without oil coolers. Some are so fixated on it that one guy with a cooler and 235F oil temps had a failure, and was desperate to get oil temp lower still for the rebuild! It wasn't the oil being too hot that caused failure...

[autoracer86]

Originally Posted by ZDan

Again, going higher in viscosity is going to do a better job of keeping oil pressure up at higher temps vs. going to an oil cooler.

275F indicated is reportedly 255F at the sump. This is just no big deal for any decent 30-weight synthetic, and if you want higher pressure than what that gives just run 40-weight. Honestly at 235F indicated I'd probably just run 0W20 street or track all year.

These cars have had engine failures with and without oil coolers. Some are so fixated on it that one guy with a cooler and 235F oil temps had a failure, and was desperate to get oil temp lower still for the rebuild! It wasn't the oil being too hot that caused failure...

I stand by what I said and as far as I can tell it's a correct statement.

Have you seen this thread ? I find more and more people trying to keep the oil cool. Running high oil temps might not been an issue but I still can't wrap my head around wanting to run higher oil temps just cause.
https://www.ft86club.com/forums/showthread.php?t=154233

[Ultramaroon]

Originally Posted by autoracer86

I stand by what I said and as far as I can tell it's a correct statement.

Have you seen this thread ? I find more and more people trying to keep the oil cool. Running high oil temps might not been an issue but I still can't wrap my head around wanting to run higher oil temps just cause.
https://www.ft86club.com/forums/showthread.php?t=154233

Both approaches are valid. They also have their own unique consequences. While Dan's engine may not frag, he must change his oil more often, and all non-metallic parts of his engine, including the glue holding it together, cook more quickly than for those who shed their internal heat. That's a personal choice. I plan on driving mine until I croak, or my license is revoked. By keeping my engine cool, I hope to preserve my valve guide seals and the like.

Also, my grandkids are still at the age where they're salivating over the car. Maybe it'll be an heirloom.

[ZDan]

Originally Posted by autoracer86

I stand by what I said and as far as I can tell it's a correct statement.

Totally agree that 235F at the gauge you have no worries as far as oil temp goes. But you're also fine at 275F indicated.

Have you seen this thread ? I find more and more people trying to keep the oil cool.

Yeah, my 0.02 on that is at 235F indicated dude has no worries even with 20-weight, but I'd still run 30-weight... Anyway I find fewer and fewer people think they need to run cooler oil temps in these cars. For *years* it was 99% of the people tracking these cars absolutely insisting you *must* run an oil cooler. It's a lot less than that now.

Running high oil temps might not been an issue but I still can't wrap my head around wanting to run higher oil temps just cause.

275F gauge/255F sump is not "high oil temp". It's even in the range where you'd be OK running non-synth given appropriate viscosity. I do recommend running higher viscosity than 20-weight tho...

What I don't get is the fetishistic obsession over lowering oil temps that are perfectly reasonable.

[new2subaru]

I think it boils down to "There's more than one way to skin a cat"

There are many people doing different things and all having good outcomes.

[Ultramaroon]

Sure, and one of them is the right way.

[ZDan]

Originally Posted by new2subaru

I think it boils down to "There's more than one way to skin a cat"

I guess my point is that the cat doesn't need skinning!

Kinda reminds me of my 240Z days, one guy in our local Z club would always go on about the 4-row aluminum radiator he put in his stockish power 240Z and how it never overheated. Meanwhile I had a stock 260Z radiator in mine and it never overheated either, on the street in traffic or on the track, while running a high-compression big-cam 3x2 45mm carbed 255rwhp 3.1 liter monster. I mean, yeah, he had a ton more cooling capacity than me, he just had absolutely no need for it!

[gen3v8]

Oil gets to a lot of places in an engine that cooling water can`t. So it picks up heat from some very hot areas. It gets a lot of heat from areas in the engine not in oil pressure. Oil is not the best for exchanging heat, but it does and it reaches far more places than coolant water. That`s why it gets so hot and not forgetting its primary purpose of lubrication.