Official S65 Rod Bearing Condition Example Thread

[DL335D]

"Specifically, Plaintiff Afzal had modified his BMW's software and transmission system and installed a supercharger, and Plaintiff Dechartivong's vehicle had been used in competitive motorsports."

One heavily modified the other was tracked. Did they really think they had a chance to win?

[Stanbul_76]

Originally Posted by DL335D

"Specifically, Plaintiff Afzal had modified his BMW's software and transmission system and installed a supercharger, and Plaintiff Dechartivong's vehicle had been used in competitive motorsports."

One heavily modified the other was tracked. Did they really think they had a chance to win?

Yeah really though I was thinking the same thing. Warranty specifically states modification to vehicles voids warranty, and thats not just for Bmw thats all cars I have ever heard of. Its too bad someone with a non modified car wasn't the plaintiff because there are plenty out there that have this failure with stock cars.

[jvictormp]

Originally Posted by TX

bumping an old thread and a very old post.
I contacted Lang. They do sell mixed sets of ACL, but they ***DO NOT*** measure any bearing from any set prior to selling. I was specifically told they only mix the sets and sell, as the measuring was supposed to be done by ACL so it wasn't their responsibility to check them. If I wanted lang to measure a set before selling it to me, then it would be several hundred $ more, and would essentially be the same cost of BE bearings.

Yeah, that's the same information I had from him.

[GewoW]

Mine at 60k miles just changed with ACL mixed set cuz BE out of stock

I should specify - 2011 with new bearing material

Really good condition!

[DL335D]

Those do look really good. I'm definitely waiting until 75k.

[Shan75]

Been meaning to post for a while.

I bit the bullet and changed out the bearings.

FYI - I purchased BE bearings with the ARP bolts.

Mine is a 2009 E90 DCT with almost 90,000 on the clock and had the last owner for 9 years before I acquired the car.

Was advised car was not tracked/raced, which I was never 100% on, but based on some conversations over paperwork with the sellers family (post payment) - I got the impression it may have been the truth.

Bearings were in REALLY top condition, with very consistent wear.
They looked VERY similar looking to GewoW's post above mine, mine may have been even cleaner. So....they did not require a change really, but still glad I did it.

I'll try to take some photos, but yeah - mine is another S65 that could have added some more km's before the swap....definitely.

[DRLane]

Originally Posted by Shan75

Been meaning to post for a while.

I bit the bullet and changed out the bearings.

FYI - I purchased BE bearings with the ARP bolts.

Mine is a 2009 E90 DCT with almost 90,000 on the clock and had the last owner for 9 years before I acquired the car.

Was advised car was not tracked/raced, which I was never 100% on, but based on some conversations over paperwork with the sellers family (post payment) - I got the impression it may have been the truth.

Bearings were in REALLY top condition, with very consistent wear.
They looked VERY similar looking to GewoW's post above mine, mine may have been even cleaner. So....they did not require a change really, but still glad I did it.

I'll try to take some photos, but yeah - mine is another S65 that could have added some more km's before the swap....definitely.

I keep seeing this comment "consistent wear". I believe they're not supposed to be worn at all... Hopefully someone can pipe in to elaborate.

Any how, congrats and smart move with the BE replacements. Enjoy

[serranot]

I honestly don't understand some of the latest posts with regard to "consistent wear" being in "top condition."

Rod bearings are not wear items. Period. Nothing should touch them with the consistency or regularity that most S65 crankshafts do.

When that happens, you really have no idea how much more wear you can get out of them. SMH!

[IamFODI]

Originally Posted by DRLane

I keep seeing this comment "consistent wear". I believe they're not supposed to be worn at all... Hopefully someone can pipe in to elaborate.

Rod bearings are supposed to operate entirely in the hydrodynamic regime, which means an oil film keeps the bearing from touching the crank journal while the engine is running. Obviously that works most of the time, or engines would seize far more often than they do. But it equally obviously doesn't work all the time, or there'd be no need for replaceable bearings and all the related headaches (design, complication, possibility of assembly error, etc.). We'd just bolt the rods straight to the crank and be on our way. Replaceable rod bearings exist because there's always some probability of stresses that'll break through that oil film. That probability is different for different engines and in different use cases. Obviously it's higher in this engine than in most others, at least with its stock bearings. So, the next question is what the wear means, and there's some room for reasonable people to disagree on that.

If a rod bearing wears to the point of knock or seizure while everything else in the engine is perfectly serviceable, that's obviously a problem. If a rod bearing shows no significant wear until something else in the engine reaches a condemnation point, that’s obviously good (for the bearing at least).

What if the bearing wears noticeably but doesn’t get to the point of allowing knock or seizure until after the engine needs a rebuild for some other reason? Is that amount of wear acceptable? If it’s acceptable, what does that mean on the scale of tens of thousands of engines? Statistically, even if the vast majority of engines’ rod bearings last until something else prompts a rebuild, a few won’t. How many premature failures is acceptable before we call it a design flaw? One percent? One-tenth of one percent?

These are all questions on which reasonable people can disagree. That, plus the lack of reliable stats and all the usual Internet-conversation shenanigans, seems to be why there’s so much disagreement over what’s normal for these bearings.

Bearing manufacturers themselves don’t seem to agree with the idea that no wear is permissible. All major bearing manufacturers have guidelines that include what constitutes “normal wear”: a consistent wear pattern with no hard boundaries over the majority of the bearing surface, without evidence of some other problem (scoring, corrosion, etc.).

Then there’s the following quote from Glyco, the manufacturer of the 702/703 bearings (source here):

If the clearance is minimal there is good conformability between the bearing and crankshaft journal. This conformability is a result of material that is worn in some parts of the bearing in the order of magnitude of μms. This process leads to less local stress on the sliding layer, a better absorption of shock loads and less wear.

That seems to suggest that with little clearance, as we all know our rod bearings have, there exists some form and amount of wear that is not only normal but beneficial. This seems to line up well with the fact that 702/703 bearings have been known to show wear patterns after just a few thousand miles.

Unfortunately, Glyco hasn’t posted pics of what this normal micro-wear might look like. We also don't know the thickness or metallurgy of the bearings' layers, and no one's measuring 702/703 bearings after they're removed from service. So, it’s hard to tell just from looking at these bearings how much of the wear is problematic.

It’s easier with 088/089 bearings because we know what they are and how they work. We know things can go south pretty quickly once that top layer is gone, and it’s easy to tell visually when that has happened. We don’t have the same knowledge for the 702/703 bearings.

Those of us in the “rod bearings should never wear” camp don’t have to do all of this hand-wringing. If it looks worn, it doesn’t matter how long it’d last; it’s sub-optimal, and thus too risky, and that’s that. I’m not so sure, personally – but that’s a different topic.

[serranot]

Originally Posted by IamFODI

Rod bearings are supposed to operate entirely in the hydrodynamic regime, which means an oil film keeps the bearing from touching the crank journal while the engine is running. Obviously that works most of the time, or engines would seize far more often than they do. But it equally obviously doesn't work all the time, or there'd be no need for replaceable bearings and all the related headaches (design, complication, possibility of assembly error, etc.). We'd just bolt the rods straight to the crank and be on our way. Replaceable rod bearings exist because there's always some probability of stresses that'll break through that oil film. That probability is different for different engines and in different use cases. Obviously it's higher in this engine than in most others, at least with its stock bearings. So, the next question is what the wear means, and there's some room for reasonable people to disagree on that.

If a rod bearing wears to the point of knock or seizure while everything else in the engine is perfectly serviceable, that's obviously a problem. If a rod bearing shows no significant wear until something else in the engine reaches a condemnation point, that’s obviously good (for the bearing at least).

What if the bearing wears noticeably but doesn’t get to the point of allowing knock or seizure until after the engine needs a rebuild for some other reason? Is that amount of wear acceptable? If it’s acceptable, what does that mean on the scale of tens of thousands of engines? Statistically, even if the vast majority of engines’ rod bearings last until something else prompts a rebuild, a few won’t. How many premature failures is acceptable before we call it a design flaw? One percent? One-tenth of one percent?

These are all questions on which reasonable people can disagree. That, plus the lack of reliable stats and all the usual Internet-conversation shenanigans, seems to be why there’s so much disagreement over what’s normal for these bearings.

Bearing manufacturers themselves don’t seem to agree with the idea that no wear is permissible. All major bearing manufacturers have guidelines that include what constitutes “normal wear”: a consistent wear pattern with no hard boundaries over the majority of the bearing surface, without evidence of some other problem (scoring, corrosion, etc.).

Then there’s the following quote from Glyco, the manufacturer of the 702/703 bearings (source here):

That seems to suggest that with little clearance, as we all know our rod bearings have, there exists some form and amount of wear that is not only normal but beneficial. This seems to line up well with the fact that 702/703 bearings have been known to show wear patterns after just a few thousand miles.

Unfortunately, Glyco hasn’t posted pics of what this normal micro-wear might look like. We also don't know the thickness or metallurgy of the bearings' layers, and no one's measuring 702/703 bearings after they're removed from service. So, it’s hard to tell just from looking at these bearings how much of the wear is problematic.

It’s easier with 088/089 bearings because we know what they are and how they work. We know things can go south pretty quickly once that top layer is gone, and it’s easy to tell visually when that has happened. We don’t have the same knowledge for the 702/703 bearings.

Those of us in the “rod bearings should never wear” camp don’t have to do all of this hand-wringing. If it looks worn, it doesn’t matter how long it’d last; it’s sub-optimal, and thus too risky, and that’s that. I’m not so sure, personally – but that’s a different topic.

This is a thoughtful, well-written post that captures the essence of the disagreement.

I happen to be in the "no wear is acceptable" crowd for the simple reason that there is no standard for how to measure acceptable wear or to determine with any degree of certainty whether one's engine is substantially at risk or not.

As I said before, rod bearings are not brake pads and there is no wear sensor that can safely take you to the edge of acceptable (since there is no standard). Accordingly, when I hear comments like "my wear was awesome and I could have gone longer," my first question is "according to what standard?" Just looking at them is not a standard, and, for our engines, it normally isn't a few stray streaks or particles but rather easily recognizable wear.

My $0.02.

[Richbot]

The point about wear though, Glyco's guidance suggests (and basic common sense suggests) that the wear must be limited to the sliding layer to be acceptable. That's not what we're seeing on a large fraction of bearings that come out, so it's sortof one of those - how much radiation is acceptable - questions. What's the normal background? Pretty low. Is normal background harmful? Probably not. Should I, a healthy person, look at all these people around me getting cancer and assume "eh background here is probably normal?" Probably not.

[Kiefermeister]

Here's mine at 156k miles. Well documented and meticulously maintained car. This was on original bearings. ACM did the replacement last week.

[Helmsman]

Originally Posted by Kiefermeister

Here's mine at 156k miles. Well documented and meticulously maintained car. This was on original bearings. ACM did the replacement last week.

156k miles, 249k km...another sign that the very majority of our shells actually keep up well. Replaced mine with extended clearance at 37k miles. Next time I'll go with a slightly less open shell, and sleep good at night.

[TX]

I’d be interesting to know along with these removals, what bearing they installed?

[Hondaman23]

I think that we will start to find (we already have some evidence) that we will not need to replace the ACL or BE bearings ever again. These replacement units were not designed to be “serviced” again since they address the root of the problem. There will be some of us that feel like we need to check the status of these replacement bearings and I want to say “Thank You” to those crazy people since you will be the ones to let the rest know if the issues are truly resolved one the improved bearings are in. I do not intend to ever do that again! But the evidence of others experience will sway me if there is wear being formed on the bearings. Keep the posts coming, and know that the most interesting posts for me will be those that pulled a set of BE bearings!!!

[Stanbul_76]

Originally Posted by Helmsman

156k miles, 249k km...another sign that the very majority of our shells actually keep up well. Replaced mine with extended clearance at 37k miles. Next time I'll go with a slightly less open shell, and sleep good at night.

Sorry what do you mean by slightly less open shell? Are you referring to BE ones?

[Fezza]

As a reference this is what stock bearings should look like. These were pulled out of a N55 engine at 60,000 miles:

[RhinoJockey]

Just got mine done at MRF. 2011 ZCP DCT with just under 75,000 miles that I've owned since 2014 with 17,000miles. Despite meticulous maintenance and warming the car before any hard driving, RBs were in bad shape. Tracked the car 5 times. Malek said he's seen bearings that have failed in better condition. Big relief to me to have them done knowing I was driving on borrowed time!

View post on imgur.com

[jzamory]

Just had my bearings replaced. The car is an '08 E90 with 89,650 miles on it. I've only owned it since February and bought it with the intention of having the bearings done for peace of mind. I replaced them with the WPC treated OEM bearings and BE rod bolts. I was originally going to go with BE bearings, but they were almost never in stock and I've heard good things about the WPC bearings and they were available so I decided to go that route. The car was clean and well maintained by the original owner (I'm the third owner, but the second only had the car for about six months) with a lot of service history. Anyway as you can see a few of the cylinders were well worn with cylinders 4 and 5 having by far the most wear. Just another data point for this ongoing discussion, but hopefully the engine has some miles left on it after this.

[Richbot]

holy crap

[Bubbles]

Originally Posted by jzamory

Just had my bearings replaced. The car is an '08 E90 with 89,650 miles on it. I've only owned it since February and bought it with the intention of having the bearings done for peace of mind. I replaced them with the WPC treated OEM bearings and BE rod bolts. I was originally going to go with BE bearings, but they were almost never in stock and I've heard good things about the WPC bearings and they were available so I decided to go that route. The car was clean and well maintained by the original owner (I'm the third owner, but the second only had the car for about six months) with a lot of service history. Anyway as you can see a few of the cylinders were well worn with cylinders 4 and 5 having by far the most wear. Just another data point for this ongoing discussion, but hopefully the engine has some miles left on it after this.

Shiny like new copper gutters. What oil are you running?

[Move Over]

Probably will get some crap for this but i bought a car recently that had 165,000 miles on it, the OEM bearings were changed at 162k miles, but they were changed with OEM new style bearings. I wasn't comfortable with that so i DIY'd again today with ACL bearings and ARP bolts. Easy and cheap as i have a lift in the garage and experience doing them 4 hours start to finish. Here's the bearings that came out with just over 3k miles. Figured I'd share