Engine Bearing Failure

[SVXRide]

Originally Posted by Dessertrunner

I agree with Tom totally so much so I am confident enough to bet $1,000 thats its a loss of pressure issue.

Heres why:-
- The good book shows the right hand side of the engine having 8 bearings (1,5,6,7, Journal & 1,4,5,6 Big ends) all being feed oil. One of these has larger requeiment due to #5 bearing the thrust as well as feeding the two big ends. We have no idea how much extra that thrust bearing will take before the bigends or if it has been designed by Subaru to get pirioty oil.
- The Left bank only supplies oil to 5 bearings (2,3,4, Journal & 1 & 3 Big end). Journal 3 is just a plain old bearing so it doesn't have the demands of #5
- When Subaru designed the oil system they needed the engine to maintain pressure at low revs as well as high. At low revs of 600 rpm the good book says the pump only supplies 5.5lpm. To get the oils system to function they
had to keep constant restriction in the oil galleries so they fitted a number of little sheet metal restricter. See attached photo. If these were removed bearing failure would result at low rpm.
- Next point is that at 8,500rpm the existing pump would be pumping 95 litre per minute. The sump contains roughly 6 litres and that is pumped around the engine 15.8 times per minute or once ever 3.8 seconds. Even if you had the best sump in the business the amount of oil in transist at any one time will be major part of the engines capiciaty.
- Oil going around the system every 3.8 secs will become highly airrated and there for no longer work effectively.

Given what I have see and learn't about the bearing failure issue over the last 6 months I am sure that once the dry sump is fitted the problem will go away. There are a number of reasons,
(1) We will get higher flow 70% more oil in the system, getting 170 lpm at 10k rpm.
(2) Due to the larger tank installed for oil the air will be removed and the quanity will alway keep the engine happy.
(3) I intend on running test then following this I will remove the restrictor plates in the oil galleries to increase flow but keeping in mind that I need oil pressure at low revs.
(4) Us thinner oil so the overall pressure at hi revs doesn't go to high.


As I have mentioned before the oil system on this engine is a work in progress and needs some testing to put solid number on what will happen with higher flow.

Tony

Tony,

Thanks for the summary. Aerated oil and bearing life never mix well

Bill

[bazza]

Originally Posted by TomsSVX

Its about use... 1/4 mile cars will never have reliability issues like a road race car. Endurance of an engine is far more difficult to obtain than a 10 sec blast of power.

As for #5 failing... its the first to lose pressure and last to get it back during surge

Tom

You've never been drag racing or built drag engines have you Tom? If you had, you prolly wouldn't have said that lol.

[Dessertrunner]

Sorry to jump in for Tom Bazza but I asked a couple of the drag guys if they every had issues with our engine over heating and they said there isn't enough time for it to be a problem. So if that's case on cooling does it apply the bearings as well?????
Tony

[bazza]

Originally Posted by Dessertrunner

Sorry to jump in for Tom Bazza but I asked a couple of the drag guys if they every had issues with our engine over heating and they said there isn't enough time for it to be a problem. So if that's case on cooling does it apply the bearings as well?????
Tony

It depends who you ask and what they're racing. I know a certain EG33 that was rebuilt every 5 drag runs due to bearing wear and it ran a dry sump! Tom stated 1/4 mile is easier on the engine than endurance. I think what he meant is making the exact same engine last on street can be harder than the strip. Then of course that depends how it's driven on the street - Granny could make it last hundreds of thousands of kms with correct maintenance... however young Johnny might have it last 50,000 kms. It's just a very flakey statement with far to many variables to be of use. Not offense intended there Tom.

Now if you look at the video I posted and research the owner, he doesn't do drag racing only - seems to do a variety of events. And in that video he accelerates for a huge amount of time, I get about 20 seconds. After you're testing - you didn't see cavitation after 10 seconds, you saw it instantly and you said it only took 30 seconds to boil.

"It was so bad that in 3rd gear the test lasted about 30 seconds before the engine boiled" - that's with 200 hp in 3rd gear (110 kph).

Now imagine what happens with 700 hp and twin turbos attached which is also heating the water up with the car accelerating to 230 odd kph?! It's going to get DAM hot if there is any weakness in the cooling system.

Also having done some 500 drag runs personally so I can speak from experience and you do see the water get hotter at the end of the run in any EJ. Also with those EG's that did the drag racing - were they going off actual ECU temp or the gauge display? Anyway I don't understand why he doesn't overheat - maybe he has the oil cooler version of the SVX pump with the extra pump inlet - although he did mention no thermostat.

Now with the bearings, drag racing is rather brutal, usually because unless you're one of the big boys with electric heaters and proper setups, everything is often cold on the staging line - oil temps in engine, gearbox and diffs - which obviously isn't ideal for the bearings.

[bazza]

Also does anyone actually have a list of the EG33 bearing failures? I think it needs to be published here. Every single engine, mods, fuel and so forth.

I made this up on the RLSC to prove that stock engines or stock Subaru bottom ends were far better than people realised. It also showed the running engines with mods and no aftermarket ecu usually ended in a quick death.

This is what we need for the EG33 so we can understand it better rather than a couple of theories. I of course agree we need a dry sump and there are issues with the oiling that need solving - however having this list will certainly reduce the unknowns.

Built engines:

EJ207 (V5 STI, open deck), forged, ARPs, 225-245 kw atw over 30,000 kms. Failed within 2,500 kms (cometic head gaskets) replaced with stock units. Revved to 8500 rpm. Aftermarket ecu tuned to suit.

EJ255 (USDM), MY98 heads, forgies, rods possibly to long, AVO head studs (used). Did head gasket (AA610's)at 25psi boost. Head stud nut thread failed. Fuel pump fail damaged big end. Motor did 19275 klms before rebuild. Aftermarket ecu tuned to suit.

EJ257 (2007 ADM) with LA sleeves + forgies + re-used ARPs + ACL HX's bearings, 245 kw atw over ~35,000 kms. 28 psi boost. Ring land fail. Revved to 8000 rpm. Stock ecu tuned to suit.

EJ20 block with darton sleeves (2.2L), TD06SL2 making >250 kw atw. Bad tune on aftermarket ecu caused catastrophic failure. Issues with ongoing water loss after rebuild, cause unknown.

EJ235, rebuilt 3 x times over 3 years trying to get a stable base. Finally starting to be reliable @ 300 kw however only 10,000 kms on the block to date. Stock ecu reflashed to suit.

EJ22, many forged mods, 200-250 kw atw, cracked bore, overboosted, issue with wiring melting, ghetto close deck mods. Aftermarket ecu not tuned for overboost condition or cold starts.

EJ22NA, many forged mods, tuned to 19 psi, driver overboosted to 24 psi, 250+ kw atw, cracked bore, after market ecu had no summer air temp compensation, driver kept driving whilst engine kept pinging.

EJ257 unopened + CP pistons, lots mods, 230-250 kw atw with AVO400L, rod out of the block at ~65,000 kms, lotsa abuse.

EJ255 unopened + CPs. V7 heads, stocky headgaskets, arp studs (new). 180-230kw . Stock ecu tuned to suit. Still running @ ~15,000kms. Torn down at ~30thousand due to excessive blow by + low compression.

EJ257 unopened. CP pistons. td06-20G @ 22psi daily. 250kw atw for 50,000km. Never blows smoke, never uses oil. Aftermarket ecu tuned to suit. Still running

EJ257 unopened MY07 CPs + re-used ARPs, 225-280 kw atw, 65,000 kms. Only noticeable damage was pistons nearly catching the bore and therefore a few scratches. Revved to 8500 rpm. Aftermarket ecu tuned to suit 98RON. Was running fine up to refresh.

EJ257, forged everything, 2.5L NA heads, 280 kw atw, 50,000 kms+?, stock bores, GT35R, this engine defined abuse! Aftermarket ecu tuned to suit. Bores a bit ovalled. Still going when pulled down.


Rebuilt stocky engines with stocky parts:

EJ20 (RS JDM) with JDM auto stock ECU - lasted 15,000 kms with usual mods. Blew head gasket and a ring land running a TD05h to 16 psi. Running 98RON with stock JDM ecu.

MY97 GTB motor, which I pulled down, replaced bearings, inspected all parts, then put back together. Did 50,000kms then blew headgasket. Has done 10+ track days as well. VF23 running 19psi, MicroTech ECU, and always used 100octane fuel at the track. Headgaskets have been replaced and motor is running again in the track car.

MY93 RS ADM motor, rebuilt @ 200k by Subaru with stock RS parts. Car run stock until i bought it at 300k so motor had done 100k now runs with VF22 @ 1bar with VOS chipped AUS RS ECU - 160kw's still going strong after 50k with track days and red line abuse use's **** all oil and blows smoke only as it's running super rich.


Stocky motors including imports:


EJ20G VF30/FMIC/TBE V2 STI RA ECU ~19psi= Piston Ring

EJ20R TT/TBE JDM ECU "Built" by MRT ~18psi = Big End Bearing

EJ20R TT/TBE/RAILS/FPR JDM ECU "Built" by MRT ~25psi = Cracked Bore, Mashed Valves/Piston

MY96 JDM EJ20 with JDM ECU - lasted 10,000 kms with TD05h running 16 psi. Blew ring land. Running 98RON with stock JDM (auto) ecu.

EJ20 (MY96 WRX) VF23, TBE, RS ECU, 16-18psi. Motor now has very low compression in 1 cylinder, suspected ringland or valve

EJ207 (V7 JDM) - Scuffing in all 4 bores. Bearings were fine. Ran with stock V7 JDM ecu on 98RON and FMIC / TBE / CAI / VF30. Original MAF housing not used, replaced with aftermarket MAF housing, no re-tune to suit. Mixtures and timing never checked for safety.

EJ20G (MY95 WRX) , V2 sti ra ecu td05 20psi did a head gasket.

EJ20 (MY95 V2 STi RA) 380cc injectors, Haltech E11, TD05 @ 18psi, parallel fuel rails, FMIC, 3" exhaust. 90,000km on motor when I got it. 98RON. Bearing fail. Bad tune possibly causing cat to block to cause backpressure to cause bearing fail - or bad tune full stop?!

EJ20K 96 V3 sti JDM engine, prova chipped ecu, vf23 20-24psi, Died a horrible death, HG's and very bad internal noises, found the bin.

EJ20 (RS ADM), 190kw VF34, ~30,000kms. Camshaft bolt snapped and timing skipped bending valves. No damage to pistons, rods or bearings.

EJ20 (JDM RS) Various Subie turbos, Haltech ECU, ~18psi, Lasted > 100Kkms (on top of 100Kkms when I bought it). Seized water pump caused the belt to skip. No damage to pistons, rods or bearings.

EJ20G JDM Legacy motor - vf28, fmic and 17psi daily. Did a total of 105,000km. Mines STI RA ecu Still running.

EJ20 (MY02 JDM GTB TT) with TD06h-20G, 200+ laps at track, est 180-230 kw atw. Aftermarket ecu tuned to suit. Still running.

EJ20 (MY00 JDM GTB TT) with BBK20G running 24 psi, 240 kw atw. Stock ecu timing, microtech for E85 fueling. Still running.

EJ20 (RS JDM) 24 psi for a long time with PowerFC / VF34P20. Still running.

EJ20 (RS JDM), 24 psi through TD06h-20G and VF23 and proper ecu management. Still running.

EJ20 (ADM RS) VF23 @ 18psi, 180kw, RS ECU, motor had done 150,000kms when I got it, did another 30-40,000kms. Still running when removed.

EJ20 (MY94 RS JDM) - 112k on it when I bought it. Did another 10,000 kms. Proper aftermarket ecu with tune to suit. VF30 @ 20 psi. Still running.

EJ20G (RS Engine) vf12, stock ecu 15 psi, then td05 v2 sti ra ecu 22psi - Still running when removed.

EJ20K 96 STI engine, Mines tuned chipped ecu,VF23 22PSI, Still running when removed.

EJ20k 97 STI engine, Power FC, VF23 22PSI, Still running when removed.

EJ20G 95 V2 sti ra Engine, Bozz speed chipped ECU, VF23 22psi Still running when removed.

EJ20G 95 WRX RA Engine, Mines Chipped ECU, VF22 24PSI Still running when removed.

EJ20K 96 V3 sti engine, prova chipped ecu, vf23 20-24psi Still running when removed.

EJ20G 95 V2 RA engine, VF23, Prova ecu, 22psi Still running when removed.

EJ20 JDM RS legacy motor. Did another 25,000 stock with variety of turbos. 140kw. Still running when removed.

EJ20 (MY93 RS ADM), TD05, TBE, RS ECU etc, 17-18psi, 98 RON fuel. Did another 40,000km. MRT chip in there which saw very lean mixtures. Still running when removed.

MY95 V2 STi RA motor, PE1820 clone @19psi. Lasted 15,000km. Run on 98RON and Mobil 10w40 diesel oil, aftermarket ecu tuned to suit. Still running when removed.

MY96 JDM WRX motor, VF23 @ 16psi, TBE, mods etc. Run on 98 RON. Still running when removed.

EJ207 (stock) + V3 heads, 100K, lots boost. Aftermarket ecu tuned to suit -~200atw, happy to rev past 8K. Still running when removed.

EJ205 ADM JDM STI v6 RA ECU, VF29, 17 psi. 165kwatw. 5000km, still running

EJ20 (94WRX) vf34p20, mods, v2 sti ra ecu, 189.9kw (18psi), still running

EJ255 (04 fozza) gtps03, mods, stock ecu tuned to suit, 211.8kw (18psi), still running

EJ20G VF12/FMIC/TBE WRX ECU still running

EJ25 VF46/TBE ADM ECU, still running

EJ20 (JDM RS motor) TD05/VF34 22psi, tracked, dragged and hillclimbed. Aftermarket ecu tuned to suit. Still running.

EJ20G (MY95 WRX) VF35, 18psi, V3 sti ecu bought with 110k, still running

EJ255 (06 ADM WRX) GTPS02 @ 18psi, 152,192km currently (20k modded) doesn't use a drop of oil, smooth as. Stock ECU reflashed. Still running.

[Dessertrunner]

Good point, not sure how many of us with engines out here left, but I get your point.
Tony

[Dessertrunner]

I had a thought (which is a really bad idea)

Some people don't or can't go to dry sumps so why don't we just over fill the oil so we still have enough when 4 litres stays in the heads,

Can some one tell me why not????
What bad things happen if we do that???

If we think it will fly then I will move the volume up on my test car.
Tony

[SilverSpear]

Tony if I am not mistaken, the additional oil will cause additional internal engine pressure. This will result in messing up all rubber seals...

[Dessertrunner]

I have measured the sump and it will take 9l full, that still isn't enough to hit the bottom of the piston but should be okay.
Danny I understand thats what people say but tell me how its a issue in our engines, I just don't see it.

Think about this if a race car doesn't have foam in the tank does it cavitate when the tank is full or when it has heaps of air.
Its when the tank has airspace.

Fill the sump up with more oil even if you lose a bit in the heads there will be plenty left to feed to pump.


So guys why won't it work????????

Tony

[icingdeath88]

This is something that is done sometimes on other engines. The Toyota 3vzfe I did some reading about on their forums for a while (for the v6 mr2 project), and I found that overfilling oil by even a couple of quarts is pretty common.

The only issue I can really think of with the EG is that on hard turns the extra oil will overflow into the heads. If it's ok for the heads to have the extra oil in them then I think it will be ok. I don't know about where the oil moves to under hard braking or hard acceleration, but that would be worth checking out. Basically as long as you are thinking of the engine as part of the dynamic moving vehicle, and account for where the extra oil might go, then I think it's definitely an idea worth pursuing.

I accidentally overfilled one of mine once by mistake (miscounted bottles and put an extra quart) and didn't notice anything different, but that was just under normal spirited driving conditions.

I am going to do some research online as to whether the EJ guys have tried this and to what effect, and report back.

I have another idea actually, that I'm going to throw out there even if it turns out to be a crappy idea. What if we put a flexible tube on the oil pickup, so that whichever direction the oil sloshes toward, the pickup would also swing toward?

[bazza]

Originally Posted by icingdeath88

This is something that is done sometimes on other engines. The Toyota 3vzfe I did some reading about on their forums for a while (for the v6 mr2 project), and I found that overfilling oil by even a couple of quarts is pretty common.

The only issue I can really think of with the EG is that on hard turns the extra oil will overflow into the heads. If it's ok for the heads to have the extra oil in them then I think it will be ok. I don't know about where the oil moves to under hard braking or hard acceleration, but that would be worth checking out. Basically as long as you are thinking of the engine as part of the dynamic moving vehicle, and account for where the extra oil might go, then I think it's definitely an idea worth pursuing.

I accidentally overfilled one of mine once by mistake (miscounted bottles and put an extra quart) and didn't notice anything different, but that was just under normal spirited driving conditions.

I am going to do some research online as to whether the EJ guys have tried this and to what effect, and report back.

I have another idea actually, that I'm going to throw out there even if it turns out to be a crappy idea. What if we put a flexible tube on the oil pickup, so that whichever direction the oil sloshes toward, the pickup would also swing toward?

At the track I've always overfilled by 500ml to 1.5L with the EJ2X's and the EG33.

As soon as you've racing you've got a fair bit of oil in the heads - the EG33 can have up to 5L in the heads, which means you've only got 2-3L left in the sump!

[bazza]

Originally Posted by SilverSpear

Tony if I am not mistaken, the additional oil will cause additional internal engine pressure. This will result in messing up all rubber seals...

I don't think that would happen. The rubber seals are the oil seal up front, rear main, cam shafts and rocker covers. None of these will be effected with a little more pressure - and you get a heap more pressure from blowby anyway.

[icingdeath88]

Originally Posted by bazza

I don't think that would happen. The rubber seals are the oil seal up front, rear main, cam shafts and rocker covers. None of these will be effected with a little more pressure - and you get a heap more pressure from blowby anyway.

Yea, I think a properly vented crankcase will be fine with the extra oil, probably just more oil for the PVC/breathers to deal with. Which should be a non-issue with a proper AOS of some kind.

So you don't think the extra oil sloshing around in the heads would be an issue? What about it sloshing front/rearward under braking/acceleration?

[bazza]

Originally Posted by icingdeath88

Yea, I think a properly vented crankcase will be fine with the extra oil, probably just more oil for the PVC/breathers to deal with. Which should be a non-issue with a proper AOS of some kind.

So you don't think the extra oil sloshing around in the heads would be an issue? What about it sloshing front/rearward under braking/acceleration?

There is oil sloshing around the heads regardless of 5L in the sump or 10L. The pump is moving 55-65L / min of oil... about 1L/second and I'm not sure how much the lifters / cam journals get but it's a lot. Plus you won't ever brake or accel hard enough to cause major issues.... maybe if it was in an aircraft haha.

[oab_au]

The main problem with the EG33 is that it is flat, and the oil is only 2" from the top of the engine, where the breathers are. Standard they blow oil mist up the rear vent, to fill the air delivery pipe, back to the air cleaner element.

With a higher level the situation will become worst. Under acceleration the oil will surge to the rear of the pan to fill the separation chamber and into the air pipe. Cornering surge will have it flow up the cam cover drains to fill this space.

So either a well baffled pan, or a dry sump, has to be the answer.

Harvey.