FA20 Engine Oiling, Bearings, and Starvation

[BRZGM3]

I was being sincere when I said thanks reaper. You've answered like 4 other questions of mine. And I already knew that info from this thread and other sources. I just wanted to be sure the cooler was the only other option so far. Thank you.

[Killianti]

Does anyone else feel like this thread has jumped the tracks?

[Reaper]

This thread should be called "latest frs problem we need to overcome with aftermarket parts"

[Element Tuning]

Ha ha it has jumped tracks so bring it back on track. Our engines and our cars are so far good to go on the oiling

Next will be the external oil pump but I'm taking a break from driving a race car on the street. Cruising in my station wagon (S6 Avant) LOL!

I guess we can't actually push much more HP without a transmission upgrade so it needs to happen for us to cover higher power oiling.

[Caspeed]

Originally Posted by Element Tuning

Yes and no. Higher oil temps always drop oil pressure. The problem is that the OEM oil pump isn't large enough to supply the required oil pressures for substantially higher than OEM hp under normal driving conditions.

So while an oil cooler will help lower oil temps and help keep oil pressure higher you'll find that most of those with oil coolers are getting only about 10 psi more oil pressure so it does help but let's get real here. Those guys tracking their cars with oil coolers and that have good data are either NA or may have 280 hp with a supercharger. So 50-60 psi is probably going to do the trick but we need a solution to run 400, 500, and 600 hp.

If I can get 70-75 psi on the street consistently I would be happy for our customers running 400-500 hp. For 600+ I would like to see 75-80 psi. If I added an oil cooler to what I've done along with the heavy weight oil I think I'm right there for a reliable high power street car.

Now track cars running 400+ hp will not be able to keep oil temps in the 210-230 F range at all. 260 is going to be realistic for a track car with a cooler so we need that oil pressure in the 85 psi range on the street so we can handle that viscosity drop while racing (we see about 15 psi drop on our STi race engine).

Oh and by the way I'm running 15w50 Red Line as I knew I would still need the extra viscosity to increase pressure.

The wider the viscosity range the more viscosity stable the oil is. Therefore a 0w50 will loose viscosity at a lower rate than a 15w50.

Also, remember that the oil distribution on a street engine is based on alot of idling. One of the 1st mods when buiilding a "Race" engine is restricting the oil flow to the heads. This serves two purposes;

1) Because "race" engines operate continuously at high RPM the heads receive more oil than they need, you eliminate overlubing.

2) It also reduces the amount of oil that has to return from the heads to the crankcase This is critical in a boxer engine (gravity is not a help, and G forces work against the return). It's possible that the sump is being pumped dry (or low) and the oil is in the heads. It's surprising how small the restrictor for the head lube can be and still have no lube issues in the valve train. If you go with a dry sump you might want to scavenge the heads.

One of the reasons dry sumped engines produce good power is that they reduce crankcase pressure. This lower pressure reduces windage from the crank & rods and helps the rings seal better.

Good thread.

[mike the snake]

I know a lot of race engines actually run vacum pumps for those reasons. My buddy drag races and his huge 500+ inch engine has a vacum pump.

I don't know enough about dry sump systems and/or if they run the crankcases at a vacum.

[Element Tuning]

Caspeed, actually what you'll find is that wide spreads of viscosity test way worse after being thermally stressed. This is something that's reported over and over again. I've done my own testing and have come to the same conclusion. Forget the 0-40, a straight 40 or even a 15w40 will be thermally more stable. It has to do with the ploymers tobmake the huge viscosity spread under test conditons. The FA runs so far outside of the normal test range for temperature you can't treat it normally.

Mike, dry sumps and vacuum pumps do help ring seal but it does not help oil pressure (just tying it to the ghread) to have less crankcase pressure as the oil pump has to pull against the vacuum. Dry sumps aren't affected because they have external oil pumps (or oem pump like the ET dry sump) fed via a tank pressurized by the scavenge lumps and the crankcase blow by (also by gravity). I raced with an absolutely wasted engine with our EJ dry sump kit and you would never know it since it will pull normal ebgine vaccuum at idle and then all the blow by oil is just recycled. LOL! Very unlikely we're pulling vacuum at 700 who even with a stage scavenge pump but it still helps

[Andreas83]

Originally Posted by Element Tuning

Sorry to hear that! You should give me a call. Sometimes "blown" isn't as bad as you think. We could probably rebuild most of what you have, perform the internal modifications so you have better oil pressure. Odds are you damaged the crank and some rods but the rest may be perfectly serviceable.

For NA you don't need to build up to "turbo" strength so it won't cost an arm and a led. Food for thought. I think you'll really regret it down the road if you put the same thing back in and then have the same exact failure (which is what you should expect).

I finally got the engine out to inspect the damages.
Second connection rod bearing was spun.
Luckily the rod was still in one piece and heads and case look ok.
So I might be good to go with a new crank and a rod.
I would love to have the internal modifications done to ensure sufficient oil pressure.
But sending the motor from Europe to USA and back is probably going to be pretty expensive.

[Element Tuning]

Originally Posted by Andreas83

I finally got the engine out to inspect the damages.
Second connection rod bearing was spun.
Luckily the rod was still in one piece and heads and case look ok.
So I might be good to go with a new crank and a rod.
I would love to have the internal modifications done to ensure sufficient oil pressure.
But sending the motor from Europe to USA and back is probably going to be pretty expensive.

Wow, did this happen in NA form?

If you look back to my original post you'll understand why this one rod bearing went first as it appears to be one of the two rod journals with shared oiling source.

What oil brand, weight, and pressures were you seeing?

Expensive to ship, yes but not as expensive as it will be if it happens again. You'll just have some options to figure out in terms of just shipping heads and building up a new bottom end or stripping down what you can and sending that. In the end if you do get sent back a rebuilt engine you will save on import duties for sure. We are always helpful on that however with international engine shipments.

Thanks,
Phil Grabow

[Andreas83]

Originally Posted by Element Tuning

Wow, did this happen in NA form?

If you look back to my original post you'll understand why this one rod bearing went first as it appears to be one of the two rod journals with shared oiling source.

What oil brand, weight, and pressures were you seeing?

Expensive to ship, yes but not as expensive as it will be if it happens again. You'll just have some options to figure out in terms of just shipping heads and building up a new bottom end or stripping down what you can and sending that. In the end if you do get sent back a rebuilt engine you will save on import duties for sure. We are always helpful on that however with international engine shipments.

Thanks,
Phil Grabow

Yes, the car is NA, its the second rod.
Valvoline 0w-20 oil, I dont have a oil pressure gauge.
Happened the day after oil change at my dealer, but they wont cover it due to mods.

[Brzzee]

Originally Posted by Andreas83

Yes, the car is NA, its the second rod.
Valvoline 0w-20 oil, I dont have a oil pressure gauge.
Happened the day after oil change at my dealer, but they wont cover it due to mods.

Regrets your dealer won't be of help to your hurt engine.
What mods have u made that caused them to make that determination?
Stateside the dealer has to show just cause that what changes u made caused the failure.
Again sorry you've have problems.
This week I'm on my ninth dealer visit for problems. 10 percent of my 7500 miles is to & from Sewell Subaru in Dallas. Last visit the maintenance tech R&R'd the transmission and failed to tighten the two bolts that hold the middle section/flex joint of the driveshaft. Finger tight only with no QA check for proper torque on a major maintenance action. Soooo not pleased. Exhaust piping kept the thing in place when I drove back within an hour of picking the vehicle up from their quality replacement of the flywheel, clutch, t.o. Bearing, and pressure plate.
Good luck with your engine repair, again sorry Subaru dealer is giving u grief. Maybe u can take the issue up line to Subaru Norway.

[Element Tuning]

Originally Posted by Andreas83

Yes, the car is NA, its the second rod.
Valvoline 0w-20 oil, I dont have a oil pressure gauge.
Happened the day after oil change at my dealer, but they wont cover it due to mods.

You can PM the answer if you like but are you just a street driver do you also track the car? From the failures I've seen this is one of two journals likely to fail first from a lack of oil pressure or starvation.

I would highly recommend people even in NA form go for a higher viscosity oil and a higher grade oil (not dealer bulk). While we are certainly in the business of building race reliable engines, it's a real shame to see a very lightly modified engine fail. This is assuming your tune wasn't detonating and pounding the bearings.

We can help as we are really the only ones who are addressing this particular issue but it will hurt a little more given the distance.

The good news is that the engine in our FRS is still racing along and has endured some extreme racing! I am looking forward to the external oil pump so we can juice up the Hp more.

[Brzzee]

Several posts have discussed transmission oil cooling.
What temps have u seen and what range do u want the OEM transmission to run based on your experiences with ur cooling efforts?

And really the same questions apply to the differential. Sorry if I'm asking proprietary information. If so just respond that the data is not for public dissemination.

Thanks again for all the work you're doing for our platform.

[Element Tuning]

Well unfortunately we were very unscientific about the transmission cooler as we had less than a week between races to swap the transmission and custom make a cooler. This means we just did it and crossed our fingers.

As far as ideal temps they very much follow engine oil temps so if you can keep it around 200-220F you're ideal but people can record 300+ on race cars. Oils just can't stay in grade at such high temperatures. I doubt street guys are seeing really high temps but I would love to see someone's data. I'm sure I'll monitor it next season but it's unlikely I'll be on this gearbox very long. I dont plan on hanging around sub 400 hp for very long.