Official S65 Bearing Specification/Clearance Wiki

[swamp2]

Originally Posted by Yellow Snow

So what's the 'effective bearing diameter' of an S54 compared to S65?

Not sure what you are asking or how that term is defined. Do you mean effective clearance or perhaps clearance ratio?

For the rod end bearings:

It seems to be a fair assumption that for the S54 and after the new bearing shells, there is 0.06 mm of clearance, that is 0.0024". The rod end journals are 1.929" dia. Those are the "average" values, not mins nor maxs from the range defining within tolerance. This latter number is from the large table posted by the OP prior in this thread. This amounts to 0.0012 in/in of clearance. This compares to 0.00063 in/in for the S65.

Thus the S65 rod end bearing clearance ratio is almost exactly half of the clearance ratio for the S54 post design change.

My (sarcastic) commentary on that is:

Sure, BMW knew the S54 rod bearings were already too tight, perhaps "fatally" so, and thus they decided twice as tight would be a great course of action for the S85 and S65.

[aussiem3]

Originally Posted by swamp2

Sure, BMW knew the S54 rod bearings were already too tight, perhaps "fatally" so, and thus they decided twice as tight would be a great course of action for the S85 and S65.

[FogCityM3]

LOL, "planned obsolescence"? wait didn't that concept originate in the auto industry?

Originally Posted by swamp2

My (sarcastic) commentary on that is:

Sure, BMW knew the S54 rod bearings were already too tight, perhaps "fatally" so, and thus they decided twice as tight would be a great course of action for the S85 and S65.

[BMRLVR]

Originally Posted by swamp2

Not sure what you are asking or how that term is defined. Do you mean effective clearance or perhaps clearance ratio?

For the rod end bearings:

It seems to be a fair assumption that for the S54 and after the new bearing shells, there is 0.06 mm of clearance, that is 0.0024". The rod end journals are 1.929" dia. Those are the "average" values, not mins nor maxs from the range defining within tolerance. This latter number is from the large table posted by the OP prior in this thread. This amounts to 0.0012 in/in of clearance. This compares to 0.00063 in/in for the S65.

Thus the S65 rod end bearing clearance ratio is almost exactly half of the clearance ratio for the S54 post design change.

My (sarcastic) commentary on that is:

Sure, BMW knew the S54 rod bearings were already too tight, perhaps "fatally" so, and thus they decided twice as tight would be a great course of action for the S85 and S65.

Maybe he means the "effective bearing area"?

[bigjae1976]

Originally Posted by aussiem3

I have raised this question before, and I will again, a highly strung engine like S65 will experience some bearing wear. I don't think it's fair to even believe, that the original bearing in an engine with a peak 8300 rpm should be a lifetime part.

But the question is what's accepted wear rate? We're seeing wear, and some are really bad, but what we don't have is a some, we can compare with and say, for an engine with X kms should wear like this. But we can't do that either.

Driving habits, climate, fuel and a lot of other things including service intervals will play a role on all parts that will wear overtime, including bearings.

This bearing wear and the fear of "I could be next" probably forced a guy in Canada to open up an engine, when the consensus on that thread is, that the issue could be totally something else.

We haven't got anywhere with this argument because we don't have vital data, on which BMW made the informed decision to make the bearings tight and going against the so-called "conventional" clearance.

We argue, throw mud, ridicule and do everything possible to make people accept our own theory, but non of these have stood up against a good dataset.

So I shall leave it hanging there ...

I think it will be awhile before we get good data of a representative population and my inclination of 80k-100k being a good target. I'm taking the view of their business. BMW makes money off of the car new, then makes money of a certain % through CPO resales, and then I would imagine BMW is looking down the road at the next and the next, next model. Most dealerships will not be excited to service your 100k mile BMW.

BMW knows this based on god knows how much marketing data.

Originally Posted by speedaddictM3

I agree. I too think the bearing clearance was done to reduce engine noise and appeal more to the "luxury" oriented clients. I also agree that it seems with proper maintenance most engines will survive the CPO period. It's people like us who have high mileage out of warranty used cars and want to keep them for a long time that are screwed. So much for the myth that the M3 is "built like a tank". Thanks a lot BMW

A piston rod sticking out of your engine block perhaps? Seriously I don't think that question has ever been answered adequately. Maybe elevated levels of aluminum and tin in the oil?

I don't think anyone is suggesting the S65 should last a million miles like a big rig diesel engine. But at the same time I don't think any engine, high strung or not, in a daily driver car has any business lasting less than 200000 km (which equates to about 10 years of use).

Old M cars that were hand built had terrible reliability. Most sports cars do not have great reliability. I guess my expectations are very different. I'm happy with 100k miles.

Originally Posted by swamp2

Although I agree with some of the post from where this came, I think this is unfounded, highly speculative and overly pessimistic. From the following thread we have the following (relatively small data set), all cars with NO engine problems. I found this in 1 minute of research. Obviously, by the nature of this forum, for each of these cars there are 10's or perhaps hundreds not reported. Also these are DCT cars only.

-114k mi
-160k mi (second hand reference)
-93k mi
-54k mi car with 30+ track events
-118k
-122k

I agree that my statement isn't based on hard S65 data but you have to consider the business that BMW is in. I think that is a strong clue as to what BMW was thinking about this whole bearing issue.

Pessimistic? I thought I was an optimist?

[Yellow Snow]

Originally Posted by swamp2

This latter number is from the large table posted by the OP prior in this thread. This amounts to 0.0012 in/in of clearance. This compares to 0.00063 in/in for the S65.

Let's not forget. The S65/S85 figures in the chart aren't factual, they are the OP's own assumptions of clearance from measuring a few cranks.

No one has listed the actual BMW listed sizes. Not even the guy on M5 board who claims his mate rebuilds dozens of engines in the M division.

[SenorFunkyPants]

Originally Posted by bigjae1976

Most dealerships will not be excited to service your 100k mile BMW.

Why? its their bread and butter...probably their biggest income stream.

Originally Posted by bigjae1976

I guess my expectations are very different. I'm happy with 100k miles.

I figure that BMW do the maths....how many cars are going to have BMW extended warranties - their income from selling them against the total payouts. Throwing big $ at cars still in warranty is something you would definitely plan against. I would work on more than 100,000 miles as a target for engine/gearbox life. Probably 150,000 would be a financially safer target.

[SenorFunkyPants]

Originally Posted by Yellow Snow

Let's not forget. The S65/S85 figures in the chart aren't factual, they are the OP's own assumptions of clearance from measuring a few cranks.

No one has listed the actual BMW listed sizes. Not even the guy on M5 board who claims his mate rebuilds dozens of engines in the M division.

I've asked BMW for the rod bearing clearance spec but have a low expectation of receiving it.
EDIT: and indeed they refused the request.

[stevens]

in the UK BMW will not allow you to take the extended warranty if your car has over 100k miles, regardless of age. Something I read in my recently policy book.

[SenorFunkyPants]

Yes you can only have the comprehensive policy up until you pass 100,000 at time of renewal. After that point you can have the "Driveline" policy whuch covers the engine, transmission and drivetrain components.

[SenorFunkyPants]

There must be a % range which is regarded as "normal" for engine failures amongst the big car manufacturers. There was a list by the UK warranty provider Warranty Direct produced from the study of 50,000 cars. But it has to be put in the context that these are all cars that don't have main dealer warranty...so will tend to be all older high mileage cars. Anyway adding the top 10 to the bottom 10 failure rates and averaging out the results gives ~0.8%...seems like a decent figure to work with.
So for 25,000 USA cars we would expect 200 engine failures.
Now all we need is for an admin to interrogate the M3post user profiles for "Drives" E9x M3 and "Location" USA to see the number of USA M3 owners in order to predict an approximate number of owner recorded failures that would be reported on M3post.

[jcolley]

Originally Posted by Yellow Snow

Not even the guy on M5 board who claims his mate rebuilds dozens of engines in the M division.

If he himself doesn't work there, why would you expect him to have that information?

At no point has he ever claimed any affiliation with BMW more than having a friend who works there. He has never made any statement about performing any repairs to any vehicle in any capacity associated with anyone other than his own auto repair shop.

He has however provided great insight and advice for the S85 community and helped many members solve problems with their vehicles including VANOS pump problems, actuator rebuild specs, and torque specs missing in TIS. After posting a an issue I had on the other forum, he PM'd and then called me to discuss it and provided a few tips to make the job easier. In my mind, that has made him a more useful contributor to the community than a large number of people in this thread so far.

Given the number of posts he has made over the years with photos, it's a bit tin-foil hattish to to claim he's only worked on one engine.

[SenorFunkyPants]

Originally Posted by jcolley

He has however provided great insight and advice for the S85 community and helped many members solve problems with their vehicles including VANOS pump problems, actuator rebuild specs, and torque specs missing in TIS. After posting a an issue I had on the other forum, he PM'd and then called me to discuss it and provided a few tips to make the job easier. In my mind, that has made him a more useful contributor to the community than a large number of people in this thread so far.

Indeed....kudos for that.

Originally Posted by jcolley

Given the number of posts he has made over the years with photos, it's a bit tin-foil hattish to to claim he's only worked on one engine.

Because fixing 30 is so believable?
Slap me with a kipper and call me a cynic but it just doesn't seem credible.

[Yellow Snow]

Originally Posted by jcolley

If he himself doesn't work there, why would you expect him to have that information?

At no point has he ever claimed any affiliation with BMW more than having a friend who works there. He has never made any statement about performing any repairs to any vehicle in any capacity associated with anyone other than his own auto repair shop.

I don't remember saying that he worked at the M division. He claims his friend does though. It's obvious from the piles of sand etc in his workshop that he himself doesn't work there.

My point was that if his friend worked in the M division rebuild plant, he would have access to the correct clearance data.

I'm pretty sure that if I claimed I had a mate in the M division I would be slapped down for telling stories and creating bias.

[regular guy]

Originally Posted by Yellow Snow

Let's not forget. The S65/S85 figures in the chart aren't factual, they are the OP's own assumptions of clearance from measuring a few cranks.

Clearances are defined as the difference between rod+bearing inside diameter and connecting rod journal outside diameter. Clearance is calculated as a simple subtraction and can be verified from the actual measurements in the data charts provided on page-1 of this thread. If these measurements are not factual, then they must be falsified, and if the clearances aren't calculated, then they must be assumptions.

Do you have any proof that the measurements were falsified in any way and aren't factual? Or any proof that the clearances aren't calculated from actual measurements and are just mere assumptions?

No, of course not.

[regular guy]

Originally Posted by SenorFunkyPants

Why? its their bread and butter...probably their biggest income stream.

I figure that BMW do the maths....how many cars are going to have BMW extended warranties - their income from selling them against the total payouts. Throwing big $ at cars still in warranty is something you would definitely plan against. I would work on more than 100,000 miles as a target for engine/gearbox life. Probably 150,000 would be a financially safer target.

Most people who I've met and buy extended warranties don't buy them from BMW, they buy aftermarket policies at cheaper rates.

[jcolley]

Originally Posted by Yellow Snow

I don't remember saying that he worked at the M division. He claims his friend does though. It's obvious from the piles of sand etc in his workshop that he himself doesn't work there.

My point was that if his friend worked in the M division rebuild plant, he would have access to the correct clearance data.

I'm pretty sure that if I claimed I had a mate in the M division I would be slapped down for telling stories and creating bias.

If I had a friend who worked for a large company and accessed information they deemed did not belong in the public domain, then published it on the internet for all to see, I feel certain I would be faced with a team of litigators pursuing me for damages and my friend would be out of a job, more likely in deeper litigation. It was pretty clear earlier (a few posts back) that BMW had no interest in sharing the information with the public. He may know what the actual clearance specs are or not, I don't think he's ever been asked.

I don't know if he's aware of this thread or even cares. I'm appreciative that he posted to warn us of a potential problem that sure enough...was verified on my car and every single other S85 that's been opened up for the purpose of preventive replacement. I have no dog in the fight either way. I will merrily drive my S85 for another 50k miles before I care again. Given what I saw when I pulled my bearings out, I doubt I would have lasted another 30k.

Again, doubt and discredit as you see fit, but I have yet to see any evidence that he's right.

The guy who stands on the street corner preaching the end of the world is near for 5 years may be a loony, but the second a big astroid hits Earth, well...dammit...he was right.

Which brings me back to the question I've asked many times. Where are the photos of bearings changed prior to engine failure with no significant wear? We can all argue, bitch, and moan about each others qualifications to speak on the matter, what each other's intentions are, and what the real cause of the wear is.

But in the end, isn't the point to make all of our engines last longer? If someone brings something to your attention to watch out for, personally, I'm thankful. Duschanio certainly doesn't seem to be making a big deal out of, just more of "eh...just change them and drive" mentality. Quite frankly, I don't care what his pedigree is, if he had never posted about it, I'd still have shite bearings in my engine.

If Regular Guy hadn't started looking into the issue, I'd still be running TWS.

Where's all the uproar about throttle actuators? Idle actuators? Stuck open fuel injectors? The accusations and questioning of the guys who brought that up?

Yet again, I'm sucked into a rant here. I'm going to go back to just driving my car. If it breaks, instead of bitching and moaning about it, I'll just fix it. If you think about...man...talk about first world problems.

[kawasaki00]

Once again Regular Guy was gratious enough to send me a complete set of new bearings and here are the results of the fitting.
I was going to get into greater detail but with the results some specs will not be posted such as bearing crush and how I arrived at these figures. The evidence is in the pictures that I am now confident that proper clearance can be achieved even with the factory shells. The bearings were fit using a Mahr Federal Air Gauge, it doesnt get anymore precision. I will not post these pics because the machines we use are specially made just for our shop. I took pics with a dial bore gauge just to show the comparison and to have some real world numbers for everyone to see.
After working the bearings here are the fitment numbers using 2.0466 crank journal

1 .0023
2 .0020
3 .0021
4 .0023
5 .0021
6 .0021
7 .0022
8 .0023

Fall off is right on at .0007-.0008 at the 45 degree mark with total fall off sitting at .0015.
There is absolutely nothing wrong with these numbers. These are typical fall off numbers and the discussion on them can be put to rest as the new bearings are the only way to really get an idea of where it is at.
These figures are right in line with what the standard bearing practices are. .0001 for each .100 journal size.
Now as far as the old bearings, there were about .0004 wear on the shell checking at different points. Fitting a worn bearing was .0018 so I guestimate that it was probably .0014 when new. The down to the copper that is observed at the parting lines only comes from multiple problems here. Low oil pressure and no flow at startup, the tight clearance of the stock bearings and the super thick 60wt oil are creating a situation where the engine is running for too long with no pressure to the rods. The crank journal is beating around inside the bearing with no wedge of oil for the cushion. The last part inside of the bottom end to get oil pressure and flow are the rods. It can be 7-8-9 or more seconds for the rods to get fully lubed.

[8k3]

kawasaki00 what did you do to the new bearings to achieve these clearances. You mentioned the word "worked." I have a new set of WPC treated bearings that are about to go in and I'd like to know the details of what should be done before this happens. Thank you

[Yellow Snow]

Originally Posted by regular guy

Clearances are defined as the difference between rod+bearing inside diameter and connecting rod journal outside diameter. Clearance is calculated as a simple subtraction and can be verified from the actual measurements in the data charts provided on page-1 of this thread. If these measurements are not factual, then they must be falsified, and if the clearances aren't calculated, then they must be assumptions.

Do you have any proof that the measurements were falsified in any way and aren't factual? Or any proof that the clearances aren't calculated from actual measurements and are just mere assumptions?

No, of course not.

Were those clearances taken from an oem crank and rods?

Were the other models clearances actual measurements, or simply taken from the wear limits on Tis?

Are you actually interested in finding out if there is a problem or not?

No, of course not.

[regular guy]

The questions:

Originally Posted by regular guy

Do you have any proof that the measurements were falsified in any way and aren't factual? Or any proof that the clearances aren't calculated from actual measurements and are just mere assumptions?

The response:

Originally Posted by Yellow Snow

Were those clearances taken from an oem crank and rods?

Were the other models clearances actual measurements, or simply taken from the wear limits on Tis?

Are you actually interested in finding out if there is a problem or not?

No, of course not.

The answer: NO.

[swamp2]

Originally Posted by kawasaki00

Once again Regular Guy was gratious enough to send me a complete set of new bearings and here are the results of the fitting.
...
I am now confident that proper clearance can be achieved even with the factory shells.
...
These figures are right in line with what the standard bearing practices are. .0001 for each .100 journal size.

Thanks for the ongoing work. I'm pretty confused though. The prior claim is that the S65 is running 0.0006 in/in of clearance (based on OP measurements). You are now claiming that the number is right at .001 in/in and is completely acceptable? This is a HUGE change and is contrary to an enormous amount of prior posted discussion.

Is achieving this clearance something that will happen in any good shop, with any good builder using good tools and process or was something special done specifically to achieve a larger clearance?

regular_guy: Any explanation for the large discrepancy here? Do we need to repeat this process with the mains as well, are those clearance ratios posted prior now suspect?