Official S65 Bearing Specification/Clearance Wiki

[speedaddictM3]

Originally Posted by Thebrain

There are many factors that pose a risk to detonation I gather. The m3/m5 seem to have an awfully high compression ratio of 12:1 which is higher than prior Ferraris until the 458.

I would be more willing to buy into the detonation and bad fuel theory if BMW didn't already have a history of bearing wear with the S54 and S62 engines. What caused their problems? Were they detonating due to bad gas too? I'm pretty sure they didn't have the ion current knock detection system that is claimed to be the cause of S65 and S85 engine problems.

[swamp2]

Originally Posted by regular guy

If it is, then the natural application of this theory is that BMW has designed an engine so poorly that it isn't durable and uses an ECU programmed so poorly that it can't even richen the mixture if it needed to.

I find the propositions that:

1. BMW completely screwed their ion knock sensing technology and its interaction with timing / mixture.
2. BMW completely did (and has for 20+ years) screwed their bearing clearances (or clearances+oil combination)

Absolutely equally improbable. How do you justify one being so much more likely than the other?

Originally Posted by regular guy

This S65 connecting rod photo might be very hard to explain for a person who believes in the detonation theory. The color of the rod big end tells a very specific story.

This is nothing but hasty generalization? Isn't this the single case observed? Certainly a very low number of such cases do not by themselves completely rule out detonation nor other effects. Last but not least, as you have already pointed out, side clearances and diametrical clearances may be separate issues.

[catpat8000]

Originally Posted by speedaddictM3

torque is far more important peak horsepower output which is a useless number outside of marketing leaflets and salesmen hype.

Then why can't a 335d diesel (~425 lb/ft torque) take the E9X M3 (~300 lb/ft torque) in a drag race?

Pat

[catpat8000]

Originally Posted by swamp2

I find the propositions that:

1. BMW completely screwed their ion knock sensing technology and its interaction with timing / mixture.
2. BMW completely did (and has for 20+ years) screwed their bearing clearances (or clearances+oil combination)

Absolutely equally improbable. How do you justify one being so much more likely than the other?

So let me see if a total layman can summarize this 45 page event.

As of July there have been a total of 57,600 S65 powered M3s sold. The breakdown is:


E90: USA/Canada: 5867 Rest of World: 3739
E93: USA/Canada: 4006 Rest of World: 3855
E92: USA/Canada: 15799 Rest of World: 24293


As near as I can determine, there are 20 or 21 engine failures we are discussing. So the observed failure rate is very, very small (less than 0.1%) but we all understand that we do not know the true failure rate and it is likely higher.

Some of these engine failures are from supercharged applications which I think are immediately suspect since the engineering done to those cars is thereby questionable and the resulting damage to the engines is possibly not even completely related to the other failures (although it may be).

There are two theories currently in vogue to explain the bearing wear and engine failure:

1, BMW uses connecting rod bearing clearances which are too small and prescribes oil which is too thick and this is causing premature bearing wear and engine failure. The basis for this theory is that some posters believe the con rod clearances BMW uses are not reasonable based on comparisons to other engines. The critics of this theory question why, if this is true, the failure rate is so low and the failure rate is not uniform by geography. Also, swamp has repeatedly pointed out that BMW has walked its own path in this area for decades.

2, The engines with bearing wear and failure are encountering detonation. The basis for this theory is the observation (which may be true but which I cannot confirm) that no engines have failed in the UK where fuel is generally of a higher octane rating than in the US. Basically, it is suggested that lower octane fuels and higher ambient temps and other possible but unknown conditions are inducing detonation in a rare number of cases. The critics of this theory have discussed the ion flow tech BMW uses to sense detonation but that's really a red herring. Perhaps it has a bug. Perhaps is detects detonation in only 99.99% of the cases. Perhaps certain electronics in the system are susceptible to degredation or failure. It's not worth any more opinions without more data.

The problem with both theories is that the failure data is not sufficient to form conclusions yet. "Experts" from bearing companies and engine building companies have asserted both cases are possible. And although it's not a popular position, I think it is nonetheless true that it still isn't clear there is a problem here which will affect a significant number of M3 owners. There may be but we don't know yet.

So that's where we are, I think.

Pat

[Cool Steel]

Originally Posted by speedaddictM3

Anyone else find it interesting how Ford can build a Mustang that is just as fast as an M3 for half the price, without requiring crazy molasses oil, without chewing up its bearings, and that can comfortably drink 87 octane gas all day long with no more adverse reaction than a mere 10 hp loss?

Ultimate Driving Machine my ass

Unfortunately were not safe over there either...

http://www.modularfords.com/threads/...linder-Failure

The difference however is that if you blow your engine in a 30k Mustang it hurts a hell of allot less than a blown engine in a 75k M3....and the cost to fix and replace is also half price. So its still a win...

I have read nothing but the good on the 392 Hemi however, and the Camaro and Vette engines....my experience with the LS3 engine ( started at 430 Hp went to 700 hp with supercharger, meth, tune and headers - not one internal engine problem) and my 5 years on those forums, never did I see consensus internal engine problem like this....plus all Vette owners give you the Corvette wave ..

[GIdriver]

Originally Posted by speedaddictM3

Anyone else find it interesting how Ford can build a Mustang that is just as fast as an M3 for half the price, without requiring crazy molasses oil, without chewing up its bearings, and that can comfortably drink 87 octane gas all day long with no more adverse reaction than a mere 10 hp loss?

Ultimate Driving Machine my ass

Really?

No problem for you. Just trade your M3 for a Mustang and your problem is solved.

Just saying...

[SenorFunkyPants]

Originally Posted by regular guy

So what are peoples thoughts on the look of the piston crown?
Its not how I expect a piston to look that is burning fuel efficiently.

[BMRLVR]

Originally Posted by SenorFunkyPants

So what are peoples thoughts on the look of the piston crown?
Its not how I expect a piston to look that is burning fuel efficiently.

Reading the piston would be a bit difficult without knowing how the car was ran right before it was shut off. Idling for extended periods/a cold start with full enrichment just before the engine was torn down can cloud the reading on the piston. From the photos I have seen, no pistons pictured show signs of detonation, and the resolution of the photos was pretty good. An up close examination of the parts would be nice to confirm this, but I suspect the same conclusion would be drawn.

I thought of a question that I would like to ask everyone in this thread..... Here goes:

If you had the choice of who recommended clearances for your engine who would it be?

1)An experienced engine builder who has a history of building race winning engines, has a pedigree beyond reproach, and has seen many bearing failures or pending failures, knows their symptoms and knows how to address them.

Or

2)An engineer who has lots of knowledge and theory behind him, but has never seen inside an engine or seen a bearing fail.

[whats77inaname]

Originally Posted by SenorFunkyPants

So what are peoples thoughts on the look of the piston crown?
Its not how I expect a piston to look that is burning fuel efficiently.

From what I can see of the rings, they look fine. Piston tops look meh, but there are a lot of mitigating situations that can cause them to be dirty like that. I *really* would have liked to see the corresponding spark plugs.

[catpat8000]

Originally Posted by BMRLVR

I thought of a question that I would like to ask everyone in this thread..... Here goes:

If you had the choice of who recommended clearances for your engine who would it be?

1)An experienced engine builder who has a history of building race winning engines, has a pedigree beyond reproach, and has seen many bearing failures or pending failures, knows their symptoms and knows how to address them.

Or

2)An engineer who has lots of knowledge and theory behind him, but has never seen inside an engine or seen a bearing fail.

Please, no offense intended but this is a thread trying to understand potential M3 engine issues. Surely you can see that this post of yours is just provoking another 5 pages on a pointless opinion-fight? You're creating a false dichotomy and you seem to be looking for war. Let's not go down that path.

If you want to argue about this sort of stupid shit, start another thread with another title.

Pat

[swamp2]

Originally Posted by catpat8000

So let me see if a total layman can summarize this 45 page event.

Perhaps with some reference to the likely related situation (almost all second hand) of similar issues in the S85 V10 from the E60 M5, I believe your summary isn't a layman's summary at all. It is about as balanced, complete and concise as can be offered at this point in time.

[swamp2]

Originally Posted by BMRLVR

I thought of a question that I would like to ask everyone in this thread..... Here goes:

If you had the choice of who recommended clearances for your engine who would it be?

1)An experienced engine builder who has a history of building race winning engines, has a pedigree beyond reproach, and has seen many bearing failures or pending failures, knows their symptoms and knows how to address them.

Or

2)An engineer who has lots of knowledge and theory behind him, but has never seen inside an engine or seen a bearing fail.

(edit: missed your post before replying Pat)

Absurd.

This is a complete false dichotomy. There are other obvious options.

I would pose an alternative question this way.

Who would you rather choose bearing clearances in your production car:

1. A race engine builder.
2. The OEM factory engineers.

My obvious choice is the latter.

Obvious contributing facts are that race engines are very unique and specialized beasts with extreme but many times very narrow operating ranges most often with much less severe operating environments (weather) and no requirements for service free lifespans in the 100's of thousands of miles.

Then there is also the massive R&D, testing, inspection, manufacturing, simulation, analysis capability that exists at OEMs and their suppliers. In the spirit that keeps surfacing of simply dissing engineers and dismissing academic contributions to automotive engineering, it is not much surprise that this sort of false dichotomy is proposed.

Am I claiming BMW or any other OEM organization is incapable of mistakes? Certainly not; cars are complex, engineering is complex, human beings and their organizations are complex, cost is often king and recalls obviously happen.

[swamp2]

Let's try to "cut to the chase" here...

What could really turn the leading hypothesis here from a hypothesis into a full fledged theory?

Unfortunately, it will cost both time and money and in some cases would subject people to additional risk. There really are quite few options/avenues. They all involve one of the cornerstones of science - experimentation. Even though these wouldn't fully rise to the level of good science (lots of data, fine control of variables, peer review, etc.), results from even a small handful of such tests should easily quell the skepticism many are expressing.

1. Reassemble an engine which exhibited bearing wear with identical but new bearings and a ground crank and providing more clearance. Then disassemble again in a similar number of miles with a similar use pattern to inspect for changes in wear.
2. Get some custom bearings with additional clearance and follow the same process as above.

A great approach would be to conduct tests on a engine tester to accelerate the availability of results. Unfortunately that would be prohibitively expensive.

I just don't see any other concrete options that will provide some certainty.

There are some other experiments that could be done that might help illuminate other aspects of this situation, but they would probably also confound the results above.

1. Reassemble an engine with worn bearings with no changes. Disassemble again some 10s of thousands of miles later to inspect for additional wear.
2. Perform the above with nothing but a change to a lighter viscosity oil.
3. Perform some additional "random spot checks" to cars that appear to have no problems in areas of the world known to provide higher octane fuel.

I would be willing to contribute financially to help fund some of these experiments. If there are as many concerned about this issue at it appears there obviously are, we could come together as a community and fund our own science! Heck, despite our differences I'd even fund (again as part of a group effort) regular_guy since it appears he has time, resources, interest and more than adequate attention to detail.

[catpat8000]

Originally Posted by swamp2

Let's try to "cut to the chase" here...

What could really turn the leading hypothesis here from a hypothesis into a full fledged theory?

Unfortunately, it will cost both time and money and in some cases would subject people to additional risk. There really are quite few options/avenues. They all involve one of the cornerstones of science - experimentation. Even though these wouldn't fully rise to the level of good science (lots of data, fine control of variables, peer review, etc.), results from even a small handful of such tests should easily quell the skepticism many are expressing.

1. Reassemble an engine which exhibited bearing wear with identical but new bearings and a ground crank and providing more clearance. Then disassemble again in a similar number of miles with a similar use pattern to inspect for changes in wear.
2. Get some custom bearings with additional clearance and follow the same process as above.

A great approach would be to conduct tests on a engine tester to accelerate the availability of results. Unfortunately that would be prohibitively expensive.

I just don't see any other concrete options that will provide some certainty.

There are some other experiments that could be done that might help illuminate other aspects of this situation, but they would probably also confound the results above.

1. Reassemble an engine with worn bearings with no changes. Disassemble again some 10s of thousands of miles later to inspect for additional wear.
2. Perform the above with nothing but a change to a lighter viscosity oil.
3. Perform some additional "random spot checks" to cars that appear to have no problems in areas of the world known to provide higher octane fuel.

I would be willing to contribute financially to help fund some of these experiments. If there are as many concerned about this issue at it appears there obviously are, we could come together as a community and fund our own science! Heck, despite our differences I'd even fund (again as part of a group effort) regular_guy since it appears he has time, resources, interest and more than adequate attention to detail.

I am still trying to identify all the blown engines. One list I have found is here:
http://www.m3post.com/forums/showthread.php?t=786615

but these are misleading in some ways. Some of the cars had tunes, some were supercharged, some never found out why their engine quit, one or two had bent valves, one or two seemed like hoaxes, and at least one of these had main bearing problems. It's very confusing.

Pat

[BMRLVR]

Originally Posted by catpat8000

Please, no offense intended but this is a thread trying to understand potential M3 engine issues. Surely you can see that this post of yours is just provoking another 5 pages on a pointless opinion-fight? You're creating a false dichotomy and you seem to be looking for war. Let's not go down that path.

If you want to argue about this sort of stupid shit, start another thread with another title.

Pat

Not looking for war at all just asking an honest question.

All of this info came to light when an engine builder measured up an S65 that he was building and couldn't believe his eyes when he looked at his measuring equipment!

A company like BMW can afford to screw up, but when a career engine builder has a few engines that fail, he looses his reputation and many times his business/job I'm the process. Due to this, the engine builder goes with clearances and specs that he knows will work since he can't afford to cover a $30k bill to replace an engine nearly as easy as a big company like BMW can!

[aussiem3]

Originally Posted by BMRLVR

.. Due to this, the engine builder goes with clearances and specs that he knows will work since he can't afford to cover a $30k bill to replace an engine nearly as easy as a big company like BMW can!

That's absurd. Do you think any car company is willing to give away money with a known issue for failure? Surely a simple fix, in this case, a proper clearance would save them hundreds of warranty claims.

C'mon, you have made some valid points in the past, but this is way out of your league, given your credentials.

I am not saying BMW hasn't made a mistake, but what we have seen so far is hell bent arguments through "assumptions" that BMW /// engine engineers and designers do not have real world practical knowledge and are paper monkeys.

This bearing issue in not new. While pointed out by some that the blueprint for the S65 would have been signed off when S85 was in production, if there was an issue with the S85 bearings, BMW would not have blatantly gone ahead with the same design and tolerance for the S65. This point has been beaten to death by others on this forum.

It's interesting to observe that the quality of fuel has been raised as an issue. When I raised the issue about bearing failures with BMW Australia, the first thing they told me was, take into consideration the quality of fuel available across the world. But I kept believing that USA would have very good quality fuel. But then various posts have lead to that not being the case. Although fuel may not be the sole culprit in this bearing saga, it may be contributing together with BMW's CBS based servicing. I would say apart from the enthusiasts like you and me, others don't care and just drive the car on a daily basis, and do the oil changes as the car calls for. Say, if the car is a weekend warrior, how long would it take to change the oil based on CBS ... may be 24 to 36 months to do the amount of km/m before the car calls for a service. Now consider the quality of the oil in this car, the sludge build up, and water etc. That's recipe for disaster.

People with blown engines, have claimed all sorts of things, to say they've done the right things, but the engine still blew. I will question these poor souls.

I don't think there is a specific reason for the engine bearing failures. Shit does happen and it can happen to me. These are some of the pitfalls that come with race-based engine design. BMW is not alone in this. People have discussed about Porsches and they have race-derived engines too.

We are up to 45 pages and we can't seem to agree on the cause nor are we close to a solution.

We are all wasting our time, including me, just adding fuel to an argument that's not going any where in a hurry. But it is all good and interesting reading and shows the kind of expertise, knowledge and experience we have on this board. My 2c.

[BMRLVR]

Originally Posted by aussiem3

That's absurd. Do you think any car company is willing to give away money with a known issue for failure? Surely a simple fix, in this case, a proper clearance would save them hundreds of warranty claims.

C'mon, you have made some valid points in the past, but this is way out of your league, given your credentials.

I am not saying BMW hasn't made a mistake, but what we have seen so far is hell bent arguments through "assumptions" that BMW /// engine engineers and designers do not have real world practical knowledge and are paper monkeys.

This bearing issue in not new. While pointed out by some that the blueprint for the S65 would have been signed off when S85 was in production, if there was an issue with the S85 bearings, BMW would not have blatantly gone ahead with the same design and tolerance for the S65. This point has been beaten to death by others on this forum.

It's interesting to observe that the quality of fuel has been raised as an issue. When I raised the issue about bearing failures with BMW Australia, the first thing they told me was, take into consideration the quality of fuel available across the world. But I kept believing that USA would have very good quality fuel. But then various posts have lead to that not being the case. Although fuel may not be the sole culprit in this bearing saga, it may be contributing together with BMW's CBS based servicing. I would say apart from the enthusiasts like you and me, others don't care and just drive the car on a daily basis, and do the oil changes as the car calls for. Say, if the car is a weekend warrior, how long would it take to change the oil based on CBS ... may be 24 to 36 months to do the amount of km/m before the car calls for a service. Now consider the quality of the oil in this car, the sludge build up, and water etc. That's recipe for disaster.

People with blown engines, have claimed all sorts of things, to say they've done the right things, but the engine still blew. I will question these poor souls.

I don't think there is a specific reason for the engine bearing failures. Shit does happen and it can happen to me. These are some of the pitfalls that come with race-based engine design. BMW is not alone in this. People have discussed about Porsches and they have race-derived engines too.

We are up to 45 pages and we can't seem to agree on the cause nor are we close to a solution.

We are all wasting our time, including me, just adding fuel to an argument that's not going any where in a hurry. But it is all good and interesting reading and shows the kind of expertise, knowledge and experience we have on this board. My 2c.

A car company is certainly not going to be willing to give away money, but be serious now, it is a numbers game...... It will cost them a lot less to do nothing than to admit there may be an issue.

I work for a company worth $50Billion, I know all too well how they (big companies) would sooner eat the cost on some items rather than admit they are wrong! Reputation is worth a lot! Don't you find is funny how the S85 and S65 are two of the only engines that BMW makes where they don't publish rod clearances in their service info?

[regular guy]

Originally Posted by catpat8000

I am still trying to identify all the blown engines. One list I have found is here:
http://www.m3post.com/forums/showthread.php?t=786615

but these are misleading in some ways. Some of the cars had tunes, some were supercharged, some never found out why their engine quit, one or two had bent valves, one or two seemed like hoaxes, and at least one of these had main bearing problems. It's very confusing.

Pat

Pat, this thread does not make any association or claims about the engines in those various threads. There are a few people here who have repeatedly and incorrectly claimed that this thread and the data presented herein is claiming this to be the cause of to those blown motors. I have never made any such statement, and unless I saw forensic photos and measurements of those motors, I probably never would. I hope this clears up some of the confusion.

[Thebrain]

For us lay people, can someone explain how if this was a bearing clearance issue, than why is it only a handful of cars out of 50k m3's produced that are even effected or coming to light on the boards. Compare to a HPFP issue of the 335 which was a design issue and certainly effected the expected number of cars that a true design or product flaw would expect to see-which is many cars.

Take out supercharged cars and then maybe 10 or less that this board knows about.

If BMW's clearance was wrong, than why is it not more pronounced to the point more chatter is going on the internet even among car magazines, reports, or something. Just does not make sense when a design issue is there, it has to effect the majority or atleast a huge chunk of cars.

A handful of cars tells me that these cars simply had their specs off from the goal clearances maybe, or maybe not. Or maybe another piece of the engine was out of spec. The consistency when using already quite small clearances probably makes it relatively easy to have a batch out of spec but still is very few.

So just for us lay people, how can so few cars be effected if the problem truly is a clearance issue design flaw? How are all the other cars surviving without getting oil to the bearings if that is the case? Forget the tech stuff, simply let us know how statistically that is possible with a true design flaw.

[regular guy]

Originally Posted by Thebrain

For us lay people, can someone explain how if this was a bearing clearance issue, than why is it only a handful of cars out of 50k m3's produced that are even effected or coming to light on the boards. Compare to a HPFP issue of the 335 which was a design issue and certainly effected the expected number of cars that a true design or product flaw would expect to see-which is many cars.

Take out supercharged cars and then maybe 10 or less that this board knows about.

If BMW's clearance was wrong, than why is it not more pronounced to the point more chatter is going on the internet even among car magazines, reports, or something. Just does not make sense when a design issue is there, it has to effect the majority or atleast a huge chunk of cars.

A handful of cars tells me that these cars simply had their specs off from the goal clearances maybe, or maybe not. Or maybe another piece of the engine was out of spec. The consistency when using already quite small clearances probably makes it relatively easy to have a batch out of spec but still is very few.

So just for us lay people, how can so few cars be effected if the problem truly is a clearance issue design flaw? How are all the other cars surviving without getting oil to the bearings if that is the case? Forget the tech stuff, simply let us know how statistically that is possible with a true design flaw.

A good place to start is the front page of this thread. Many of those questions are answered on that front page. As I mentioned only one post above yours, this thread does not discuss or try to explain or try to make any claims for failed engines that have not been disassembled, measured, and photographed. This thread doesn't try to explain blown motors for supercharged cars.

But YOU might find this quote interesting. It's something I found in another thread.

Originally Posted by Mike Benvo

This is like the tenth 2011-2013 car that I've heard of in the last 3 months spinning bearings.

Scary. That's the only word I have to describe it.

[Thebrain]

For someone who seems to push a lot of data to back the bearing issue, you did not answer my question. Even in general, how can a true design flaw not cause the vast majority of product to fail similarly if indeed the design flaw is as severe as is being suggested? 10 failed m3's? Out of 50k. Negligible. Most cars Benvo sees certainly has mods or has been driven hard so that explains that maybe but even then I I would like a general explanation of how a drastic design flaw does not effect thousands of m3's out of 50k m3's built?

[BMRLVR]

Originally Posted by Thebrain

For someone who seems to push a lot of data to back the bearing issue, you did not answer my question. Even in general, how can a true design flaw not cause the vast majority of product to fail similarly if indeed the design flaw is as severe as is being suggested? 10 failed m3's? Out of 50k. Negligible. Most cars Benvo sees certainly has mods or has been driven hard so that explains that maybe but even then I I would like a general explanation of how a drastic design flaw does not effect thousands of m3's out of 50k m3's built?

There may be 50K M3's, but probably only 10% of them are represented here! No figures can be drawn from the total production numbers vs. the amount if failures on M3post.

Anyhow, the the tight clearances in the S65 and S85 are such that not all engines are going to fail, but how do you know if your engine is one that has a journal on the top end of the diameter spec, and a rod on the bottom end of spec? In this scenario maybe all but one cylinder may be fine...... But it only takes one cylinder to cause an issue. This is not fear mongering on my behalf, I am just giving my opinion based on all the technical training and experience I have had the fortune of receiving. If I were assembling an engine, any engine, I would not assemble it without seeing a minimum of 0.0075" per inch if journal diameter, period.