BE Bearings In-Depth: Oil Flow, Oil Pressure Analysis

[Bucki14]

Originally Posted by Obioban

It is not reasonable to expect a small manufacturer to be able to collect this level of data. Hell, the information presented in this thread is far and above the norm. The tools required for the data you're asking for would make any bearing project a non started.

At this point, there's no question BMW's engineers got it wrong, even with all that data. Far from the first time they've gotten something wrong, too-- they're far from faultless.

Do I think these are a fix? I don't know. But, I do know the stock design is flawed. So the assumption that BMW got it right, because they had access to that data, is as flawed as the bearing design is.

HA he really thinks just because they're BMW engineers they get it right every time? Hell some cases they accept whatever marginal loss the data may have been showing them then as acceptable based off w/e cost targets they might have calculated. (low risk vs. high cost for changing)

Everyday we (also an OEM automotive engineer) discuss phenomenons we can't find true solutions too, but GOD bless the customers believe we get it right 100% every time.

[AutoTalent]

January 2017 update:

Table of Contents

• Testing Results: BE Bearings SP1527H
  • Overview
  • Cold/Warm Start Analysis
    • Cold/Warm Start Data
    • Cold Start Graphs
    • Warm Start Graphs
  • Oil Pressure Analysis
    • Average Oil Pressure at various temperatures vs. RPM
    • RPM of minimum oil pressure (4-BAR, 58-PSI)
    • Absolute Minimum Oil Pressure at various temperatures vs. RPM
    • Absolute Maximum Oil Pressure at various temperatures vs. RPM
  • Oil Flow Analysis
    • How oil flow changes with different oil temperatures and RPM
  • Average Oil Pressure and Oil Flow

Testing Results: BE Bearings SP1527HK

Current Snapshot: 2017-01-31

Previous Snapshots:

• 2017-01-31
• 2016-12-31
• 2016-11-30

Overview

Cold Start Analysis

Summary Oil Pressure, Oil Flow Tests

Once you start your car, have you ever wondered how long it takes for oil pressure to build and oil flow to start? This is the section that shows what it looks like.

The following chart amd graphs will show what it looks like from the time you press the "START" button to 30-seconds later. The chart shows how long from “START” until 70% and 90% oil pressure is attained. After analyzing some of the data, it appears the throttle input might have been influencing the maximum oil pressure and flow. Had I known this, I would have not introduced any throttle until 30+ seconds after starting the car.

BE Bearings


BMW Factory 702/703 Bearings

• Most likely outlying data caused to throttle input

Summary
According to this chart, the BE Bearings take less time to reach 70% and 90% oil pressure compared to their BMW OEM counterparts. Not only is it less time to reach full oil pressure, it seems significantly less time to reach full oil pressure. This is a bit of a shock to me and something I never expected to see.

Trend 2017-01
Three temperature ranges showed improvement over previous baseline, one temperature range gave back 0.1 second over previous baseline.
Trend 2016-12
Four of six temperature ranges showed improvement over previous baseline.

Cold Start Graphs

Summary
These graphs show both BE Bearing and BMW Factory bearings (as lighter colors). It's very clear from these graphs, that the oil pressure comes up faster with BE Bearings than BMW Factory bearings. Having oil pressure come up faster and lubricating the bearings is a huge benefit to reduce bearing wear and increase bearing longevity. This was an unexpected surprise that we didn't anticipate. The graphs also show no decrease in oil pressure over factory bearings. This should allay fears that increased clearance would decrease oil pressure, especially during this critical "Cold Start" time period.

Oil flow does seem to modestly increase as well. This was an anticipated outcome, but it's good to see it on the graphs.

Warm Start Graphs

Summary
The trend with continues from our Cold Start graphs to our Warm Start graphs. Oil pressure comes up faster with BE Bearings than BMW factory bearings. Oil flow shows modest increases as well, but we'd say this is fairly inconclusive -- especially above 80c. Those graphs contained too much throttle input, and we think that contaminates the results. Now that we know this, we will see if we can filter out the results containing too much throttle, and moving forward will capture results without any throttle until 30-seconds has passed since starting the engine.

Oil Pressure Analysis

Average Oil Pressure at various temperatures vs. RPM

These graphs show the oil pressure average of all available samples at various temperatures and throttle ranges over RPM. The graphs do change slightly between 5%, 30%, and 50% throttle. The primary graph, 50% throttle is shown here. Click the thumbnails of the other graphs to enlarge each one.

RPM of minimum oil pressure (4-BAR, 58-PSI)

If minimum oil operating oils pressure is 4-BAR (58 PSI), then it’s interesting to see on this graph at what RPM that goal is achieved. Again, that answer depends on oil temperature – as oil is more viscous and produces more pressure the colder it is. As these graphs show, the minimum operating oil pressure at minimum RPM appears to be right around 2500; that’s where we get minimum 4-bar pressure regardless of oil temperature.

The following chart shows average oil pressure vs. RPM. It shows what RPM achieves minimum recommended 4-BAR (58-PSI) oil pressure. This chart highlights areas that have increased performance, decreased performance, or stayed the same. Areas marked in GREEN show an increase in performance. Areas marked in RED show a decrease in performance. Everything else is unchanged.



Summary: There was one area of decreased performance, but multiple areas of increased performance. The increased performance is starting to make more sense after seeing how cold and warm starts come up to pressure quicker with BE Bearings than factory BMW bearings. The same phenomenon may be at play here, or may be something difference.

Trend 2017-01:

• 5% Throttle: no change
• 30% Throttle: no change
• 50% Throttle: returned to normal at 96-97c, 100-101c

Trend 2016-12:

• 5% Throttle: no change
• 30% Throttle: improved at 102-103c
• 50% Throttle: improved at 96-97c

Absolute Minimum Oil Pressure at various temperatures vs. RPM

So far, the data being shown are averages across millions of samples. But what about absolute minimum and absolute maximums?

These are the same set of graphs as above, but show the absolute minimums. The absolute minimums are the minimum oil pressures collected across all temperature ranges. They are graphed here to show just how low the pressure can go. Some of this may have been observed during hard cornering (more on that later). So it's hard to draw any hard conclusions based on these graphs. They are offered for informational purposes only to let the reader draw their own conclusions.

Absolute Maximum Oil Pressure at various temperatures vs. RPM

Conversely, the final graph in this set shows the absolute maximums. There's no need to show maximum graphs for different throttle levels because the maximums are absolute and every graph would be the same.

Oil Flow Analysis

How oil flow changes with different oil temperatures and RPM

These graphs show the oil flow average of all available samples at various temperatures and throttle ranges over RPM. The graphs do change slightly between 5%, 30%, and 50% throttle. The primary graph, 50% throttle is shown here. Click the thumbnails of the other graphs to enlarge each one.





Summary
Overall, oil flow increased with BE Bearings over factory BMW 702/703 bearings. For upper oil operating temperatures, the oil flow seems to have increased substantially. At lower oil operating temperatures, the results are inconclusive -- just by looking at the graphs.

Our hopes with BE Bearings were to allow a modest drop in oil pressure, so long as it was accompanied by an increase in oil flow. These graphs don't tell us much about pressure yet, but they do show rather significant increases in oil flow.

Trend 2017-01

• 5% Throttle: Oil flow at all temperature ranges below 100c stayed about the same. Oil flow above 100c continues to get higher and higher, especially in the mid-RPM ranges; not so much, if any at high-RPM ranges though.
• 30% Throttle: Oil flow at all temperature ranges below 102c stayed about the same. Oil flow above 102c continues to get higher and higher, similar to 5% throttle observations.
• 50% Throttle: Same as 30% Throttle. Oil flow at mid-RPM to upper-RPM ranges for 100c and above shows nice gains.

Trend 2016-12

• 5% Throttle: As more data samples become available over time, the data starts to converge. Oil flow increased 0.25 - 0.50 GPM almost across the board in all temperature ranges and RPM bands.
• 30% Throttle: Same observations as 5% throttle.
• 50% Throttle: Same observations as 5% throttle.

Average Oil Pressure and Oil Flow

These graphs show the average oil pressure and average oil flow average of all samples between 98-119c, and throttle ranges over RPM. The graphs do change slightly between 5%, 30%, and 50% throttle. The primary graph, 50% throttle is shown here. Click the thumbnails of the other graphs to enlarge each one.





Summary
Primarily, we want to know if BE Bearings cause an average decrease in oil pressure, and if so: how much? We also want to know if the BE Bearings increase average oil flow, and if so: how much?

This is the graph answers both of those questions in a rather obvious way.

• Oil Pressure: Oil pressure does seem to decrease slightly with BE Bearings. This is most likely due to the extra clearance. But the amount of decrease is between 2-3 PSI, over a 70+ PSI average. Assuming the 73 PSI average, a 3 PSI pressure drop is equal to 4% of the total. Whether it was the 5%, 30%, or 50% throttle input, the results were all the same: a 2-3 PSI drop over a 73 PSI average. This is proof positive that the S65 variable displacement oil pump is doing its job.
• Oil Flow: The most significant change between factory and BE Bearings is the oil flow. We were hoping for a modest increase in oil flow to offset a modest decrease in oil pressure. But the resulting oil flow is nearly double with BE Bearings over the BMW 702/703 bearing counterparts. Having double oil flow over the bearing surface increases the wedge strength and keeps the bearings cooler. The results with BE Bearings seems to be a huge win, much bigger than any of us expected.

Trend 2017-01

• 5% Throttle: Oil pressure showed about a 1-PSI drop in high mid-to-upper RPM ranges. However, oil flow made very strong gains in the same area and all the way to high RPMs. Oil flow increased approximately 1-GPM over the last sample period. This is a VERY STRONG showing.
• 30% Throttle: Like 5% throttle, oil pressure showed about a 0.5 to 1-PSI drop in mid-RPM ranges. Oil flow also made very strong gains in the same area and all the way to high RPMs. Oil flow increased approximately 0.75-GPM over the last sample period. This is another VERY STRONG showing.
• 50% Throttle: Same results as 5% and 50% throttle, with oil flow increasing about 0.5 - 0.75 GPM instead of 0.75 - 1.0 GPM.

Trend 2016-12

• 5% Throttle: As more data samples become available over time, the data starts to converge. Oil pressure began to converge to BMW 702 pressure levels. What was a 2-3 PSI drop with BE Bearings, has gone down so about a 2.5 PSI drop. Oil flow showed a reasonable increase in all RPM bands above 5000. The wild variations seen in previous data start to disappear as more data samples are available.
• 30% Throttle: Oil pressure got smoother, but otherwise didn't change enough to mention. Oil flow showed a reasonable increase in all RPM bands above 4000.
• 50% Throttle: Oil pressure got smoother, but otherwise didn't change enough to mention. Oil flow showed a reasonable increase in all RPM bands above 3600.

[AutoTalent]

Here's the easiest way to read the January 2017 update.

• See the post immediately above, or post #134.
• Search for "Trend 2017-01"
• All graphs are updated with new data
• If you want to see the older updates or historical data, click any of the "Previous Snapshot" links.

Statistical median and mode data is now available for download from the main wiki page. See links in post #1 or click below.
http://wiki.rcollins.org/core/index...._Flow_Analysis

The data file formats are also described at the main wiki page.

[SaNGRia]

I was already driving with confident since we re done with BE+ARP. That result gives me to push my limits even harder

[LangRacingDevelopment]

The data you've posted is really helpful and looks very similar to other BMW engines. It's seems obvious that if you increase any clearance in the oil system that you will see a pressure drop and an increase in flow. I'm surprised that anyone felt the need to prove this as it's really the only thing that could happen. The small amount that the volume and oil pressure changed makes sense to me, since the actual dimension change of these bearings compared to stock bearings is so small its almost negligible. I say this because I bought a set and measured them.

There's a premise here that I don't buy into. Increasing oil volume is not always a good thing. Could it be a good thing in this case? Perhaps, but you'll never be able to prove that it is. You also won't be able to prove that reducing the volume of oil flow is a bad thing.

For the sake of argument, let's assume increased oil volume is good, then you have an argument for switching to 0w-40 or some other thin oil. Why even bother using a bearing with larger clearance, just change the oil and accomplish the same thing. I'm not saying that is what you should do either. My main point is that you do not know enough to be claiming to have solved a problem here. There are so many variables in this "experiment" that aren't controlled for that drawing any conclusions from them is a bit ridiculous.

What I see in this data is that there is an oil pressure relief valve that seems to open up at around 95psi (depending on which graph you look at).I see that, like other engines, once the oil warms up the oil pump cannot keep up with the engines oil requirements and tops out at around 60psi, somewhere significantly below the peak oil pressure that was produced when the oil was cold. That alone would make me think that you're moving in the wrong direction by increasing bearing clearances.

More importantly I think its dangerous to make people believe that their rod bearing problem is solved when they install these bearings and that they can put 200k miles on their engine without ever worrying about bearings again. The solution is to change out these bearings at a reasonable interval, not to loosen the bearing clearance.

[houston]

"Reasonable interval". What is that? My engine gave up at 17000 miles. The engines are flawed and bearings should not be a wear item or cause catastrophic failure so often in engines that don't have mileage or track use / abuse. Simple fact, BMW fucked up, their lips are currently sealed and lawyered up because they know they fucked up.

I applaud any attempt at resolving this issue. But replacing shit for shit (oem for oem) does not seem like a reasonable solution to me.

I would/will do BE or the next hottest thing as soon as my two year warranty is up on my replacement engine ...if it lasts that long. I have zero comfort or faith in the reliability of my car or any other BMW after this horrific experience.

[LangRacingDevelopment]

It's a simplistic way of thinking that if you see a spun bearing the bearing is the problem, unfortunately things aren't that simple. Bearings spin for a number of reasons that aren't due to bearing itself. Ignoring all other possibilities is a mistake.

Some engines don't last 10k miles and others last 200k miles if all of the bearings are incorrectly designed.

[houston]

Agreed. I still don't know if the rod bearing or mains spun first on my car. I also don't know if perhaps the crank was the problem, the bearing... the jerky as occasional starts from the dct. The fact that I drive more short distances than long distances.

However, I know the engines are flawed, and seeing as I only play car guy on the internet;I have to rely on real people doing a lot more R&D than I do to help provide guidance on possible remedies.

The clearances are too tight.. seems to be the case. Some have had success with 0w-40, but perhaps they got lucky lucky in engine component roulette that BMW plays and they would never have had an issue anyhow.

BMW is not helping out so we have to look to the aftermarket and th community

[UPSROD]

Originally Posted by houston

"Reasonable interval". What is that? My engine gave up at 17000 miles. The engines are flawed and bearings should not be a wear item or cause catastrophic failure so often in engines that don't have mileage or track use / abuse. Simple fact, BMW fucked up, their lips are currently sealed and lawyered up because they know they fucked up.

I applaud any attempt at resolving this issue. But replacing shit for shit (oem for oem) does not seem like a reasonable solution to me.

I would/will do BE or the next hottest thing as soon as my two year warranty is up on my replacement engine ...if it lasts that long. I have zero comfort or faith in the reliability of my car or any other BMW after this horrific experience.

Rod bearing are and have been a wear item since they were invented! They are designed to be replaced!

[BMRLVR]

Originally Posted by LangRacingDevelopment

The data you've posted is really helpful and looks very similar to other BMW engines. It's seems obvious that if you increase any clearance in the oil system that you will see a pressure drop and an increase in flow. I'm surprised that anyone felt the need to prove this as it's really the only thing that could happen. The small amount that the volume and oil pressure changed makes sense to me, since the actual dimension change of these bearings compared to stock bearings is so small its almost negligible. I say this because I bought a set and measured them.

There's a premise here that I don't buy into. Increasing oil volume is not always a good thing. Could it be a good thing in this case? Perhaps, but you'll never be able to prove that it is. You also won't be able to prove that reducing the volume of oil flow is a bad thing.

For the sake of argument, let's assume increased oil volume is good, then you have an argument for switching to 0w-40 or some other thin oil. Why even bother using a bearing with larger clearance, just change the oil and accomplish the same thing. I'm not saying that is what you should do either. My main point is that you do not know enough to be claiming to have solved a problem here. There are so many variables in this "experiment" that aren't controlled for that drawing any conclusions from them is a bit ridiculous.

What I see in this data is that there is an oil pressure relief valve that seems to open up at around 95psi (depending on which graph you look at).I see that, like other engines, once the oil warms up the oil pump cannot keep up with the engines oil requirements and tops out at around 60psi, somewhere significantly below the peak oil pressure that was produced when the oil was cold. That alone would make me think that you're moving in the wrong direction by increasing bearing clearances.

More importantly I think its dangerous to make people believe that their rod bearing problem is solved when they install these bearings and that they can put 200k miles on their engine without ever worrying about bearings again. The solution is to change out these bearings at a reasonable interval, not to loosen the bearing clearance.

When the S54 had rod bearing issues what was BMW's solution? They added bearing clearance with redesigned set of bearings and specced 10W60 since the added clearance could handle a heavier oil.

What is BE doing about the rod bearing issue in the S65/S85? Adding rod bearing clearance on the S65 and S85 with a redesigned set of bearings so that there is enough clearance to take advantage of the OEM Specced 10W60.

Nothing groundbreaking has been attempted with these bearings. All this thread is doing is showing the data that is being collected and putting up for everyone to view.

P.S: I can see some of your understanding of hydraulics principles with regards to a positive displacement pump in a hydraulic system is incorrect. If you want we can take this offline and discuss further.

[houston]

Originally Posted by UPSROD

Rod bearing are and have been a wear item since they were invented! They are designed to be replaced!

I never said they were not... you may have stopped reading before the end of the sentence.

[SaNGRia]

Well, if I have any problem related to my BE bearings, BE stands behind me and investigate the issue. If they find out that my bearings are KAPUT, they are replacing my whole engine. Does BMW do anything like that after your warranty is gone? Or is that really matter to them what part is failed after the warranty is done?

I see and feel more sincere to make a business with people who is really taking their time and working hard to solve a serious problem than just throwing the same exact parts like nothing happen!

I am so appreciative for BE and I feel a lot confident when I am driving the car on the limits!

Is there a possibility that my engine can blow with BE? Yes!

How smart to replace worn bearings with same parts on a low millage , non track used s65/s85 ? To me, Not too much!

Or someone can come up with another research and says, Hey I actually made several tests and found out that bearings are getting worn not because of bearing itself just because of "X" and here is the proof and here is the replacement part! Then I can change my mind!

But so far we did not see any failed BE Bearing. (Knock on the woods) !

[LangRacingDevelopment]

I can't wait to see how that first warranty claim turns out. Good luck ever proving to a company that your engine failed because you put BE bearings in it and not because whoever installed them didn't install them incorrectly.

There's some things that you can warranty without having any real liability, rod bearings would be one of them.

[LangRacingDevelopment]

Originally Posted by BMRLVR

When the S54 had rod bearing issues what was BMW's solution? They added bearing clearance with redesigned set of bearings and specced 10W60 since the added clearance could handle a heavier oil.

What is BE doing about the rod bearing issue in the S65/S85? Adding rod bearing clearance on the S65 and S85 with a redesigned set of bearings so that there is enough clearance to take advantage of the OEM Specced 10W60.

Nothing groundbreaking has been attempted with these bearings. All this thread is doing is showing the data that is being collected and putting up for everyone to view.

P.S: I can see some of your understanding of hydraulics principles with regards to a positive displacement pump in a hydraulic system is incorrect. If you want we can take this offline and discuss further.

If there is evidence that BMW changed the rod bearing clearance on the S54 at any time I would love to see it. I've only seen that posted on forums with no evidence to support the claim.

Even if they did do this, I am fairly certain I have seen more failed S54 engines than anyone else on this forum and I can tell you for certain that the rod bearing recall made no difference in the 2003-2006 engines, they still fail just as frequently as the engines from 2001-2003.

I agree with you in that nothing ground breaking has been done with these bearings, the changes made were minor, its just another option that costs more than the bearings BMW sells. If they cost less than BMW bearings, I would use them, but they don't.

[OM VT3]

Originally Posted by LangRacingDevelopment

If there is evidence that BMW changed the rod bearing clearance on the S54 at any time I would love to see it. I've only seen that posted on forums with no evidence to support the claim.

Even if they did do this, I am fairly certain I have seen more failed S54 engines than anyone else on this forum and I can tell you for certain that the rod bearing recall made no difference in the 2003-2006 engines, they still fail just as frequently as the engines from 2001-2003.

I agree with you in that nothing ground breaking has been done with these bearings, the changes made were minor, its just another option that costs more than the bearings BMW sells. If they cost less than BMW bearings, I would use them, but they don't.

Didn't realise BMW have lead coated bearings...

[Green-Eggs]

Originally Posted by LangRacingDevelopment

I can't wait to see how that first warranty claim turns out. Good luck ever proving to a company that your engine failed because you put BE bearings in it and not because whoever installed them didn't install them incorrectly.

There's some things that you can warranty without having any real liability, rod bearings would be one of them.

Some guy already tried (to pull a fast one):
http://www.m3post.com/forums/showthr...y#post20248860

Originally Posted by LangRacingDevelopment

If there is evidence that BMW changed the rod bearing clearance on the S54 at any time I would love to see it. I've only seen that posted on forums with no evidence to support the claim.

It might just be folklore as you say. I know your history with S54 and if anybody wanted to school us on the S54 history, I'd trust you over just about anybody else. With that said, I do think I remember seeing the spec change in some BMW service bulletin (SIB). I just don't remember where I saw it or where to find it any more.

...its just another option that costs more than the bearings BMW sells. If they cost less than BMW bearings, I would use them, but they don't.

Originally Posted by OM VT3

Didn't realise BMW have lead coated bearings...

The last set of BMW S65 leaded bearings I bought (088's/089's) cost me more wholesale than BE sells their bearings for retail. The newer tin/aluminum bearings are cheap in comparison.

[Obioban]

Originally Posted by BMRLVR

When the S54 had rod bearing issues what was BMW's solution? They added bearing clearance with redesigned set of bearings and specced 10W60 since the added clearance could handle a heavier oil.

What is BE doing about the rod bearing issue in the S65/S85? Adding rod bearing clearance on the S65 and S85 with a redesigned set of bearings so that there is enough clearance to take advantage of the OEM Specced 10W60.

Nothing groundbreaking has been attempted with these bearings. All this thread is doing is showing the data that is being collected and putting up for everyone to view.

P.S: I can see some of your understanding of hydraulics principles with regards to a positive displacement pump in a hydraulic system is incorrect. If you want we can take this offline and discuss further.

BMW never changed the rod bearing specs on the the S54-- the early/recalled bearings just weren't manufactured to their specification.

10w-60 was also the oil the engine was originally designed around-- marketing just briefly got to have their way at launch that all it needed was 5w-30.

[Green-Eggs]

Originally Posted by Obioban

BMW never changed the rod bearing specs on the the S54-- the early/recalled bearings just weren't manufactured to their specification.

10w-60 was also the oil the engine was originally designed around-- marketing just briefly got to have their way at launch that all it needed was 5w-30.

Being involved with BE on this, here's my take on what you said. Most things that involve bearing specs, also involves clearance. Let's assume Clevite didn't "forget" to add copper/lead, or babbitt on a manufacturing process they've used since the early 1970's, maybe longer. Eccentricity could be a spec change, but in our experience, BMW wouldn't have been involved in that decision. Maybe the locating pin wasn't in the right spot. That seems unlikely because then bearings wouldn't fit in the rods.

Everything else also seems to affect clearance. So if there was something that wasn't manufactured to spec, then it surely involved clearance as well. Maybe the shell was too thick or too thin by a few ten thousandths -- that changes the clearance. Maybe the shell diameter was too small or too big by a few ten thousandths -- that changes the clearance. See what I mean?

I wonder if anybody has any more information about what specific part of the bearing wasn't manufactured to spec because the most likely ones I can think of also affect clearance.

[JonM]

Originally Posted by Obioban

BMW never changed the rod bearing specs on the the S54-- the early/recalled bearings just weren't manufactured to their specification.

That is my understanding too. The first S54 bearings were made by Glyco, a Federal-Mogul company. The service action/next batch were made by Clevite.

There are pics of the logos on the bearings in this thread from 2004:
http://www.bimmerfest.com/forums/sho...hlight=bearing

[Obioban]

Originally Posted by Green-Eggs

Being involved with BE on this, here's my take on what you said. Most things that involve bearing specs, also involves clearance. Let's assume Clevite didn't "forget" to add copper/lead, or babbitt on a manufacturing process they've used since the early 1970's, maybe longer. Eccentricity could be a spec change, but in our experience, BMW wouldn't have been involved in that decision. Maybe the locating pin wasn't in the right spot. That seems unlikely because then bearings wouldn't fit in the rods.

Everything else also seems to affect clearance. So if there was something that wasn't manufactured to spec, then it surely involved clearance as well. Maybe the shell was too thick or too thin by a few ten thousandths -- that changes the clearance. Maybe the shell diameter was too small or too big by a few ten thousandths -- that changes the clearance. See what I mean?

I wonder if anybody has any more information about what specific part of the bearing wasn't manufactured to spec because the most likely ones I can think of also affect clearance.

I wasn't trying to take a stance on the s65 bearing clearance situation-- just clarifying S54 history

[BMRLVR]

Originally Posted by LangRacingDevelopment

If there is evidence that BMW changed the rod bearing clearance on the S54 at any time I would love to see it. I've only seen that posted on forums with no evidence to support the claim.

Even if they did do this, I am fairly certain I have seen more failed S54 engines than anyone else on this forum and I can tell you for certain that the rod bearing recall made no difference in the 2003-2006 engines, they still fail just as frequently as the engines from 2001-2003.

I agree with you in that nothing ground breaking has been done with these bearings, the changes made were minor, its just another option that costs more than the bearings BMW sells. If they cost less than BMW bearings, I would use them, but they don't.

From an article you wrote on your website you state that you think that BMW's explanation of bearings being manufactured incorrectly was "merely an excuse and the recall was actually an update to a bearing with larger clearance".

I realize that further along in the article you clarify your stance on what you feel is the issue, but nonetheless you admit that you think that BMW increased rod bearing clearance midway through S54 production. Why are you denying this now?

Here is a link to your article: http://www.langracing.com/finding-a-...aring-failure/

[Scharbag]

I was just wondering if there has been any more data made available for the BE bearing oil flow/pressure analysis?

And a big thank you to all the contributors to this post!

Cheers,