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Old 02-25-2019, 04:25 PM   #51
xX_STI_Xx
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Quote:
Originally Posted by BDGWRXTR View Post
these things just inherently burn oil.
110% correct.

Boxer engines (like Porsche, some airplanes, etc...) don't drain oil as good as "V" type engines or "I" type engines. The cylinders sit on their sides, so naturally the oil settling off of the cylinder walls will collect at the bottom-side of the cylinder when you turn off your car. When you start it the next time, that "puddle" of oil is burned and consumed. Now imagine repeating this hundreds of times between oil changes....its quite a bit of oil it eats.

Does it make it a bad engine? No! There are more pro's than con's of the Boxer motor. Topping of your oil is a tiny sacrifice for the bigger pro's of these engines.
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Old 02-25-2019, 04:31 PM   #52
viper_crazy
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Quote:
Originally Posted by BDGWRXTR View Post
Correct the 2008+ wrx does not have a factory oil cooler
I'll second this.

IIRC, one of the coolant lines that goes to the factory cooler runs to a third port off the water pump. 2008+ WRX do not have this third port unless you accidentally upgraded your pump to an STi pump like me.
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Old 02-25-2019, 04:33 PM   #53
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@xX_STI_Xx, does oil not also drain off cylinder walls in a vee or inline engine when it is shut off as well? That dog doesn't hunt...

I agree 100% on the oil drain-back not being as good, but the oil trapped in the cylinder walls doesn't care how the cylinder is oriented, the oil will still follow gravity and pool around the piston rings in a vee or inline engine, where in a flat engine the oil just pools at the lowest point in the cylinder bore.
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Old 02-25-2019, 04:33 PM   #54
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Quote:
Originally Posted by xX_STI_Xx View Post
110% correct.



Boxer engines (like Porsche, some airplanes, etc...) don't drain oil as good as "V" type engines or "I" type engines. The cylinders sit on their sides, so naturally the oil settling off of the cylinder walls will collect at the bottom-side of the cylinder when you turn off your car. When you start it the next time, that "puddle" of oil is burned and consumed. Now imagine repeating this hundreds of times between oil changes....its quite a bit of oil it eats.



Does it make it a bad engine? No! There are more pro's than con's of the Boxer motor. Topping of your oil is a tiny sacrifice for the bigger pro's of these engines.


I get the occasional oil puddle burn off "smoke" on cold starts
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Old 02-25-2019, 11:45 PM   #55
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Originally Posted by car_freak85 View Post
@xX_STI_Xx, does oil not also drain off cylinder walls in a vee or inline engine when it is shut off as well? That dog doesn't hunt...

I agree 100% on the oil drain-back not being as good, but the oil trapped in the cylinder walls doesn't care how the cylinder is oriented, the oil will still follow gravity and pool around the piston rings in a vee or inline engine, where in a flat engine the oil just pools at the lowest point in the cylinder bore.
Sure, the concept is the same across any piston-type combustion engine (V, I, or H layouts). However, like you mentioned, the oil drains back down with gravity between piston skirt & cylinder wall MUCH better in a (V) or (I) type engine than a Boxer (H) motor. Why? Consider the expansion and contraction of the piston rings when they are hot vs. cold. Piston rings are gaped to allow for expansion when the motor is up to temp right?....so when the engine cools down, the rings contract and the gaps or ring openings are more pronounced or apparent...thus allowing oil to continue to drain back down the cylinder walls via gravity. This does not happen on the Boxer motor. The oil settles at the lowest point of the cylinder wall and remains there until the motor is run again.

Again, nothing serious as Porsche's are designed the same way. Just like Porsche's, we just need to check our fluid levels more often that's all.
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Old 02-26-2019, 03:55 PM   #56
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Quote:
Originally Posted by xX_STI_Xx View Post
Piston rings are gaped to allow for expansion when the motor is up to temp right?....so when the engine cools down, the rings contract and the gaps or ring openings are more pronounced or apparent...thus allowing oil to continue to drain back down the cylinder walls via gravity. This does not happen on the Boxer motor.
Piston rings on Subaru engines don't expand and contract with applied heat?
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Old 02-26-2019, 04:22 PM   #57
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Quote:
Originally Posted by car_freak85 View Post
Piston rings on Subaru engines don't expand and contract with applied heat?
They do, I was referring to it in the context of comparing other engines that have better oil drainage off of the cylinder walls because of gravity compared to a flat design. Oil makes its way down the cylinder walls and in-between the pistons when the rings contract and make room for gravity to drain the oil. With Subaru's this is irrelevant (they do have rings that contract and expand)....but oil won't drain regardless due to the natural design of the flat sitting cylinders....nothing is pushing the oil back down in the pan when the cylinder is sitting sideways leaving small puddles of oil sitting at the lowest part of the cylinder wall while its sideways.

Hope this makes sense. This has been explained before on these forums...no?
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Old 03-02-2019, 12:00 AM   #58
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does anyone use a engine additive ?
like a dura lube or slick 50?


my car had the motor replaced just before I bought it. the shop upgraded the windage tray and oil pickup to kb parts and head studs to arp.

everything I searched out before buying my car after you put the crap filter on pointed to abuse, lack of oil changes and running it dry.

the oil pick up tube seems to be way overblown by the haters as well as the ringland issue. also due to over reving and bouncing off limiter.

I was shocked at all the cars I looked at that were beat down. I was lucky to find my car in such great condition with 5000 km build.

but the previous owner had a rod b spin on a hot day in traffic on the hwy. older guy seemed very responsible. car was sold in late 08 as a 09. may have had a 08 block.
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Old 03-02-2019, 01:01 AM   #59
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Originally Posted by psc77 View Post
but the previous owner had a rod b spin on a hot day in traffic on the hwy. older guy seemed very responsible. car was sold in late 08 as a 09. may have had a 08 block.
These are the kind of failures I am interested in - I think there are a few notable variables for that spun bearing.

You make it sound as the previous owner was quite fussy, so I assumeh he would have used the factory recommended oil - which from memory is a 5w-30.

It was hot on the day of the spun bearing too. With a 30wt oil already being pretty thin for its application, I would say this could have contributed to the cause of the spun bearing.

I personally run a 5w-40 oil in my Subaru, and will not use a 30wt oil.

I remember reading somewhere that even Subaru recommended a 40wt oil when using the car in track conditions.

Driving on the highway/traffic with the oil temp hotter then normal can almost be track like conditions for the oil.
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Old 03-02-2019, 01:50 AM   #60
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he had his changes done at a shop so they would have used 5-30.
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Old 03-05-2019, 10:31 PM   #61
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A lot of assumptions about how oil works based on no knowledge of the oil film barrier vs viscosity, pressure and flow in here.
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Old 03-05-2019, 10:38 PM   #62
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Quote:
Originally Posted by Booki View Post
Have been wondering this for a while,

While I have not personally spun a bearing in a motor - I have only had my subaru for about 10,000km on a fresh motor, but it seems alot of others have.

Now a spun bearing is generally due to lack of oil or oil pressure, whether it be from literally low oil in the oil pan, the engine is using oil, pcv issues etc.

I want to dismiss low oil related failures - these are easily preventable. Checking your oil.

Another type of failure can be tune related - knock/pre detonation is the culprit here.

Now - What about the failures that are not caused by tuning/low oil issues?

I have heard of people with fairly new, low mileage/well maintained cars spinning bearings - what could be the cause?

I feel that there are so many engines that spin bearings around the 2008 year - is this a coincidence? Is there a defect/issue with the oiling system on those era case halves?

I have found a thread where some users reporting doing some port/smoothing work on the oil ports - unsure if this fix's the issue.

While I have not been in the Subaru engine building scene for long - I am curious as to why it seems there are alot less EJ205/7 failures compared to the EJ25, especially of this 2008ish era.

Just thinking outloud anyway...wondering what you all think

Not paying attention to oil levels and trying to drift around corners like rwd vehicles, small percentage due to cracked oem oil pickup tubes sucking in air and not providing a perfect film, and overzealous tuners and owners running too much boost on an oem map sensor that doesn't allow enough headroom to control fuel and timing accurately. And of course you could have the perfect storm...with a combination of all three.

I've had two ej18s that never spun a bearing, run an ej20k on 93 with around 4psi more boost than stock for several years with no bearing issue,run a phase 1 ej25d na on an audm ej25d legacy ecu for a few years, and an ej257 hybrid with ej20k heads for a few years with no bearing problems. (cracked a 100mm overbored cylinder liner).

The engine that cracked a liner had the killerB pickup and windage tray. They're going into my sleeved block, along with their aluminum pan. As mentioned, the pickup is not even close to $300. They shouldn't have to substantially lower their cost, just so people from other countries can get it for the same price domestic customers do. This is similar to me wanting to get a https://www.nengun.com/sard/jet-pump-killer instead of the http://www.radiumauto.com/Venturi-Je...-Kit-P760.aspx version. I prefer the simple design of the sard version, but the radium is a good bit cheaper, partially because it's in the states. I'm not going to complain though, everyone has their advantages.

Then you have people who have one used subaru, get super excited and push it to its limits before they've owned it long enough to realize the actual condition of the engine. They kill it and whine and sell the car and head back to mitsubishi or honda.

Last edited by 2slofouru; 03-05-2019 at 11:08 PM.
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Old 03-05-2019, 11:05 PM   #63
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I would say a lot of engine failures could have been avoided. Most people underestimate the power of stupidity.
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Old 03-05-2019, 11:43 PM   #64
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Quote:
Originally Posted by GrundleJuice View Post
A lot of assumptions about how oil works based on no knowledge of the oil film barrier vs viscosity, pressure and flow in here.
My understanding, the higher boost/combustion pressures you have - the harder it is on bearings, the larger clearance's you should run? Of course then selecting a oil viscosity and pump to hit the target pressures you want to run to suit with the modified bearing clearance's.

Do not have much/any knowledge on the oil flow characteristics or flaws on the EJ blocks though...Been lurker nasioc and found a section where people had smoothed out some ports
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Old 10-22-2019, 01:17 AM   #65
Speed Assault
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Originally Posted by Delphi View Post
People drive these cars hard as hell.

So the major contributors to rod bearing failure in order of most common cause are as followings. (Note this is only my opinion from my experience)

1.) Oil starvation due to running low.
2.) Oil thinning out (5-30 shearing to 5-20) combined with extended pulls (4th gear highways pulls) causing an extreme amount heat load in the already thin oil basically causing a significant pressure drops.
3.) Mixture of 1 and 2
4.) Oil pickup
5.) Bad luck
thanks for posting.
Not sure about the oil being low. spun #4 and Full synth oil was full. no mods at the time.
My .02
Just read that doing pulls in 5th gear, not good, doing pulls below 3k RPM, not good. Causes the blow by and other bad stuff.
two times found small oil residue in IC hose
Have a 08 wrx I was 2nd owner at 36K miles and at 53K miles the #4 spun. Even though oil was fine, always changed oil around 3k. I had used royal purple. After engine block replaced I stopped using royal purple and did my research , changed to Mobile, Castrol GTX, 1 round of AMS oil, many rounds of Rotella T6 and now onto Motul X-clean- like it.

Now at 112K miles Turbo blew!
had subi mech do a compression test, leak down test to figure out why.
coolant into the turbo. and found head gasket tested leakage.
The day this happend Yep, drove hard.
So from on, drive nicer, and continue to research on engine. Consider Air/Oil separator, .
Really sucks this happend, I really wanted a wide body 2014 WRX. but couldnt find any that were solid.
My 1986 Toyota I drove like a stock car, rally truck, jumped it, drove in the dunes and the only issue was at 178K miles where it broke an exhaust valve (half mooned it) easy fix. So after this WRX, going back to toyota.
sorry for extra ramble.

Last edited by Speed Assault; 10-22-2019 at 01:27 AM.
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