ANOTHER oil temp thread

[NoHaveMSG]

Originally Posted by Dzmitry

Ah yes, you did mention that. I am aware of this, I just misunderstood your correlation to the data. You're right, though the data may show this with the lowest psi dips, it is hard to know where it actually occurs in the RPM range (which is typically in the 6K+ RPM range as you say). Agreed that this is the most important issue with oil on this platform, not so much the temperatures themselves.

EDIT: This is actually why I have been most interested in following ZDan's case for some time now. Though it may be just luck, it is interesting to know that his car has held up so well over all the tracking he has done at high RPM's, probably with a lot of oil pressure creeping toward the pressures you mention.

Yeah, that is why I bought the equipment I did. I wanted to see real pressure numbers at RPM and temp. I didn't get it installed last night. I may try today but I still have a lot to do. The nice thing about the SSI-4 from Innovate, is that I should be able to just buy another pressure transducer and temp sender and wire it direct. I'd like to pull pressure temp data pre/post oil cooler. I have a spare timing cover(actually a whole other spare blown engine) that I am going to tap for additional senders. It just comes down to time.

[Petah78]

Can someone explain what is cavitation? I think it's when air is introduced into the oiling system thus lowering pressure (air collapses). But why does this only happen when the oil gets hot?

[Dzmitry]

Originally Posted by Petah78

Can someone explain what is cavitation? I think it's when air is introduced into the oiling system thus lowering pressure (air collapses). But why does this only happen when the oil gets hot?

https://www.ft86club.com/forums/showthread.php?t=134863

[Limitless_BRZ]

My oil temp, I had to relocate my oil cooler so it’s 100% open, vented hood as well.. more
Air flow in & out.

[suppjc]

Originally Posted by NoHaveMSG

I am not particularly fond of that data as I don't see an equal PSI/rpm correlation on my own car. Even running 0-20, I am pretty sure the oil pump cavitates. I build oil pressure till about 5800RPM and then it drops. I bought sensors for logging oil pressure and temp, waiting on my RPM reference sensor. I have a tool that plugs into these and will log the data.

FWIW I have been tracking my car on 0-20W with an oil cooler for 5-6 years. I regularly see oil temps in the 240-260F range. Buy good oil if you are hard on your car.

I just started to wonder what you meant by good oil. I'm currently on Pennzoil Platinum 0w-20, which says full synthetic. Is there any other property that I need to look out for other than being fully synthetic and the weight of the oil?

Thank you.

[Capt Spaulding]

Originally Posted by suppjc

I just started to wonder what you meant by good oil. I'm currently on Pennzoil Platinum 0w-20, which says full synthetic. Is there any other property that I need to look out for other than being fully synthetic and the weight of the oil?

Thank you.

You can wade WAAAYYYY into the weeds with this question looking at kinematic viscosities, shear stability, and a host of other technical detail. Pennzoil Plat is, by every definition I've seen a good oil. I use it in my car and the engine seems marginally quieter on it than the Subie shop oil. For my money, any name brand full synthetic in 0w-20 should be fine. Depending on the severity of the service the car sees (very hot ambient temps, tracking, beating the shit out of it) you may want to go up a viscosity grade (e.g. 5w-30). Just change it regularly and enjoy the car.

Just keep in mind, that every oil has a religion based on it and its believers will defend it to the death.

[Dzmitry]

Originally Posted by suppjc

I just started to wonder what you meant by good oil. I'm currently on Pennzoil Platinum 0w-20, which says full synthetic. Is there any other property that I need to look out for other than being fully synthetic and the weight of the oil?

Thank you.

As Capt Spaulding said, there can be so much to consider if you want to dig into it. Skip to the basics - oil weight and a reputable brand. Another thing to consider is GF-6 oil came out fairly recently, so it could be useful to upgrade to the latest and greatest oil. It should always have a mark somewhere stating whether it is GF-5 or GF-6 rated. It's likely that most oils you see (especially online) are already selling the latest product, so no searching will really be necessary.

[suppjc]

Originally Posted by Dzmitry

As Capt Spaulding said, there can be so much to consider if you want to dig into it. Skip to the basics - oil weight and a reputable brand. Another thing to consider is GF-6 oil came out fairly recently, so it could be useful to upgrade to the latest and greatest oil. It should always have a mark somewhere stating whether it is GF-5 or GF-6 rated. It's likely that most oils you see (especially online) are already selling the latest product, so no searching will really be necessary.

IIRC, the one I bought has the GF-6 rating. Prior to buying the oil, I looked up the new rating, and it sounded more appealing than the GF-5 rating, so I went with it.

https://www.canadiantire.ca/en/pdp/p...-0289329p.html

Thank you.

[Petah78]

Originally Posted by Dzmitry

https://www.ft86club.com/forums/showthread.php?t=134863

So from what I have read, and if I understood the article, cavitation is caused by “bottleneck” somewhere in the system resulting in high and low pressure. This causes the oil to “bubble” (oil boiling going from liquid to gas and back to liquid). In the case of our system, the thread suggests that the stock FA oil pickup tube is the bottle neck resulting in cavitation. The suggested remediation is the killer B pick up but I have not seen much info about this from my search. Am I on the right track?

Thanks.

[Dzmitry]

Originally Posted by Petah78

So from what I have read, and if I understood the article, cavitation is caused by “bottleneck” somewhere in the system resulting in high and low pressure. This causes the oil to “bubble” (oil boiling going from liquid to gas and back to liquid). In the case of our system, the thread suggests that the stock FA oil pickup tube is the bottle neck resulting in cavitation. The suggested remediation is the killer B pick up but I have not seen much info about this from my search. Am I on the right track?

Thanks.

Yes, except it is not so much that the threat suggests the pickup tube to be the bottleneck of our system. It is more that this part may help some in certain conditions and is also a fairly easy part to replace as a potential solution. Unfortunately, there is no clear indicator through the research that cavitation can be avoided with the killer B pickup, or even reduced for that matter. The idea is that it may certainly help prevent it.

Currently the best solution to avoid the drop in pressure at high RPM's is proper cooling. Whether it be an oil cooler or hood vents or a combination of multiple things, if you are able to keep your temps near factory spec for oil temps and pressures, then you should be avoiding the problem. Many have been trying to find other ways around it, with great potential, but nothing has fully resolved this problem with the twins - and I don't believe it ever will be resolved as it is more of a design flaw so to speak, rather than a simple part replacement to fix it.

[NoHaveMSG]

Originally Posted by Petah78

So from what I have read, and if I understood the article, cavitation is caused by “bottleneck” somewhere in the system resulting in high and low pressure. This causes the oil to “bubble” (oil boiling going from liquid to gas and back to liquid). In the case of our system, the thread suggests that the stock FA oil pickup tube is the bottle neck resulting in cavitation. The suggested remediation is the killer B pick up but I have not seen much info about this from my search. Am I on the right track?

Thanks.

The Killer B pickup has the potential to help, if you get one that is made right. There are other issues in the system that cause problems highlighted by that thread. He did a lot of porting and matching passageways to improve flow.

I wish there was an easy way to add the WRX oil pump to our engines but it wouldn't work without a ton of modification, and it would exaggerate the cavitation issue. So it would not really be a solution unless you updated the whole system.

[Petah78]

It's strange though as I have seen some members that has regularly track driven their cars go without issues for years. I seem to assume that most spun bearing issues are related to the valve spring recall rather than oil temp related. I am sure it's ideal for lower oil temps but I have also read that adding an oil cooler also reduces oil pressure negating the benefits.

[NoHaveMSG]

Originally Posted by Petah78

It's strange though as I have seen some members that has regularly track driven their cars go without issues for years. I seem to assume that most spun bearing issues are related to the valve spring recall rather than oil temp related. I am sure it's ideal for lower oil temps but I have also read that adding an oil cooler also reduces oil pressure negating the benefits.

I haven't had issue really. 5-6 years of tracking my car, though last year I only got to do one track day. It is mostly the FI guys that have issues but the NA cars will and can spin rod bearings too. I blew up my spare engine, but that was due to kicking out rocker arms.

I would just like to improve it to help longevity.

[DarkSunrise]

Originally Posted by Petah78

It's strange though as I have seen some members that has regularly track driven their cars go without issues for years. I seem to assume that most spun bearing issues are related to the valve spring recall rather than oil temp related. I am sure it's ideal for lower oil temps but I have also read that adding an oil cooler also reduces oil pressure negating the benefits.

That's true, but not all oil coolers are built the same. Generally speaking, a narrower width oil cooler with more rows (taller) will have much less of a reduction in oil pressure.

http://www.setrabusa.com/products/oi...ine/index.html

Same for larger oil lines with gentler bends. The goal is that the oil cooler reduce temps to a large enough extent to more than off-set the small drop in oil pressures that it causes.

A little spitball math here. The Setrab link above shows the pressure drop across a Setrab 613 is around 4 psi. In my experience, a typical front-mount Setrab 613 setup (Perrin, Racer X, etc.) will reduce oil temps by about 40 F on this platform. From the pressures shown on this link, that means a 613 will still add another 16-17 psi oil pressure at 7000 rpm (assuming 235 vs. 275 F oil temps).

https://www.ft86club.com/forums/showthread.php?t=91820

So it's still adding a net benefit despite the fact that the Setrab 613 IMO is a pretty marginal setup on this platform (without doing something to increase its efficiency like a vented hood). From what I've heard, a well designed 19 row cooler can drop oil temps on this platform around 50 F.