The OEM rod bearings debate
 

Hey guys! I am about to start my "adventure" of building a motor for my car. However after lurking the forums over the past year I have seen a few people comment on issues with OEM bearings. And like every other "problem" you see in a community of this size sometimes things get skewed out of propotion. Sometimes a small problem wasn't a problem and it was just simply a different issue altogether that looked like a problem.

So I thought it would be a good time to openly debate this topic as a number of us are starting to get ready and / or are putting a fair amount of money into a forged bottom end for higher horsepower applications. There are a number of manufactures such as Dynasty, Full Blown, and others who have "shortblocks" prepped and ready to go. All using OEM bearings. A number of companies are saying the OEM are just fine. But I have also spoked to a number of individuals who swear by the fact that the OEM bearings are a severe problem at 300+ WHP.

This topic can get a tad confusing because you see a number of people running 300+ 400+ 500+ on their cars without any issue from the factory. The reality is that we don't know how much these individuals actually drive at these horsepower levels. So how much of a problem is there with this?

I had started researching bearings and it is not an easy solution as of yet. I know @Don@Accelerated is currently producint modified rods that fit a custom set of ACL bearings he has worked on which is one option. I also know a local engine builder that has a coating technique to strengthen the rods (Although it is still in testing from what I know). I personally have contacted a number of manufactures.

Kings engine bearings has told me that they wont even start looking into bearings for roughly six months for this car. As they have a large list of other cars that are currently more in need of bearings. Lets face it not many people are really doing builds from the eyes of bearing companies. 50 builds is a very small number for a company to mass produce for.

ACL is closing their factory down in june 2014. This was announced a while back and at this time I don't think they have any desire to produce bearings for this car as there is little reason for them to "innovate" new products when they are shutting down their factory.

Mahle Is currently not producing any bearings. I will call them again today to ask if they have plans to produce for this vehicle.



Accelerated performance has told me they had a number of builds with bearing issues. I cannot find any reference on this forum to these individuals. However a lot of the car community simply is not on this forum.

I know @cf6mech has had trouble with his build that was built by AWDtuning that was pointing towards rod bearing failure. He has since rebuilt his engine using Don@Acceerlated's modified pauter rods with ACL bearings and as far as I know has had success.

You can follow cf6mech's posts on the topic here as when he was breaking ~400WHP he was starting to have issues.
http://www.ft86club.com/forums/showt...t=25673&page=2
http://www.ft86club.com/forums/showthread.php?t=44765

Are there any shops and / or users that have modified engines that would like to contribute info into this debate? I am looking to re-do my entire setup and looking to invest a "hefty" amount of money. I would hate something as simple as a bearing issue destroy my investment and ruin my day. :)

Surely there is somebody out there that has non-factory internals? I would love to see some input on anyone that has modified internals with factory bearings.

What you also do not know and cannot factor is:

improperly set clearances
bad line bore
installation error
driving habits
preventative maint

I could probably list another half dozen

I work on industrial machinery which utilize different types of lead,bronze babbit etc. If the lubrication is adequate, tolerances are maintained
and temperature is within range,a factory bearing will hold up no problem.

I have seen instances of bearings destroying crankshafts in industrial applications because the material was too hard.i would rather replace bearings than crankshafts

This is the exact reason I made this thread. I am hoping it is an install issue or another issue that "looks" like a bearing issue. I am literally about to pull the trigger on an expensive bottom end build. I stopped after reading about "possible" issues. I only have 1 confirmed motor with issues. And a shop that said that they had "other" issues but no on else has actually confirmed.

I would love to see the failed bearings. A number of vendors have told me that they are 100% confident in the oem bearings. I talked to Crawford earlier this morning and their staff confirmed that their "test" car is still running OEM subaru bearings and that the tach was reporting over 15k since that engine was assembled.

I also called ACL in Australia to confirm that they will in fact be closing down, they will in fact not be making bearings for this platform. They also confirmed that if they were it would be 2-3 years due to current desire for bearings for this platform. I asked them if I could purchase a one off set, or one off production for a high dollar value and was told it is unlikely that they would be able to do that with the factory shutting down.

It is starting to look like modified rods or oem bearings are the only two options for the time being, and likely the next 6-18 months. I am going to PM cf6mech and see if he has any photos of his failed bearings.

You might get better info if you post this in the forced induction forum. That said if you are doing a strong engine build wouldn't you look at upgrading these just for peace of mind?

If you read my post these do not exist, nor will they for some time. I literally offered ACL thousands of dollars to make a limited run set.

Power Enterprises is about the only bearing maker I know of that makes stuff that's "better" than stock (it's a different design and I'm not sold on it myself, but I've seen 1000+HP 2JZ's run them fine).

King is known to be, well, crap. At least in the other car circles I've run in.

Factory is usually more fine tuned than aftermarket (having more size variations to get the clearances spot on). On many other cars they're the go-to for the best available, and usually only not used because of cost or availability.

Keep in mind we're talking about hydrostatic bearings here, there's no real "wear" or contact taking place here. Generally if they're a crap bearing, they're not consistent in size and construction, as they're really only shims in such a system. Therefore, any failure is more likely due to other issues (detonation hammering them, oil getting too hot/thin, etc)

This is exactly what I was going to say. I'd avoid aftermarket bearing unless I 100% knew that the OEM ones wouldn't stand up to it and even then I'd decide if I'd want to risk spending all that money on a re-build that might need to be re-done.

There's so much that goes into re-building an engine, especially these newer ones with very specific tolerances, that I'm never sure I'd trust someone to do it perfectly, myself included. If it's not perfect it will need re-doing in the not too distant future and big cost again.

We have been building race motors for several years and have found today's factor bearings can take a beating. That being said your bearing are only as good as that time you take to set them up. There are a few coatings you can us to help all of your internal parts. We have had our motor open just to spec everything. We are building a motor for the 2014 season and we will be running stock bearings.

I will chime in on this post as I am one of the few that has had bearing failure that caused a short block replacement. Overall bearings are relatively strong even factory bearings. Based off of inspection, what I have found is an oil starvation issue and not really a bearing problem. I think people are over thinking this bearing issue and need to look more at the oil pump and oil combination. Also bearings shouldn't be that difficult to find as all you have to do is give most bearing companies the specs and they should have them made already (our rods aren't special). I can only speak for non-FI but it should still be relevant.

Just my two cent

I do think there is an issue with the OEM bearings at high hp FI applications,...I feel others aren't putting ACL or aftermarket bearing in because they are not available so they roll the dice. I do believe its an oiling issue, which an aftermarket performance bearing addresses with more oiling clearance. The stock bearing is hard, extremely hard, to hard for a performance application in my opinion. I had bearing failure on E85 with no detonation with a very sound tune on a built motor running close to 400whp Using Amsoil 10W 40. I'm now equipped with Accelerated Performance Pauter rods with ACL bearings and at 300whp @ 10 psi with no issues.

Thanks for chiming in! Do you have any photos of your failed bearings by chance? I have also been wondering about an oil issue. I had planned to with a friends shop and see if we can make modifications to the OEM oil pump to increase the output if possible. Do you by chance have any photos of your failed bearings?

Thanks for chiming in. I appreciate you getting back to me in my PM as well. Its good to see some people who have had failure come in here. I also know the company that built your motor builds a lot of specifically subie motors... so I also take into strong consideration if they had an issue as this is their "realm". Given this is a new motor, new clearances and overall different... but the overall manufacture is still the same. So many processes are still similar.

It is interesting to hear that they are just too hard, that I could understand. Just to keep as much info in the debate c6mech also mentioned the coating was coming off of the bearings. Was it flaking? Or was it coming off in smooth line similar to contaminants in the clearance zone?

While a little off topic, given the audience in here, this might be the best place to ask. Has anyone compared the FA20 oil pump to that of the FA20 Turbo? And does anyone know if the OEM bearings are 2 or 3 layer or possibly a newer tech such as sputter bearings?

When the WRX hits the ground we'll find out, we haven't had anyone dissect the JDM engine for us at this point so the WRX is probably when American tooners will try.