Official S65 Bearing Specification/Clearance Wiki

[B767capt]

Stole this from the M5board. Got another set of S85 bearings posted up today with 32K on them.

[marksae]

^ What kinda driving was done on that car? Mainly street? Lotsa track time?

Anyway, the evidence is pretty disturbing. I'll have to send my oil out to Blackstone during my next oil change. My car currently has almost 41k.

[kawasaki00]

Regular Guy was gratious enough to send me bearings to look at and measure and hardness test.
What has been observed is the original 088/089 bearings are a copper/lead content while the 702/703 bearings are of an aluminized tin/silicon compound.
Measurements with my mic are as follows, I am in no way saying what is right or wrong but there is always a tenth or two between different people, just because I measure one way is not to say another measurement is incorrect. What matters is the same guy measuring the crank and the clearance for the final outcome.
088 .07875
089 .07885
091 .0837
090 .0836
702 .07855
703 .07875
Measurements are pretty much in line with what others have documented up until they get polished.
What is a MASSIVE change is the hardness of the bearings. I will not get into the difference of what is right or wrong here but just know the new 702/703 bearings are a huge jump in hardness
The average hardness for the 088/089 bearings are the same at 16.2B Scale
The average hardness for the 702-703 bearings are the same at 61.8B Scale

This puts to rest the theory that one bearing is harder than the other relative to the old vs new ones.
We can work bearings to get a few tenths when needed at our shop. The big one here is not only are we gaining on the average .0002-.0003 by going to the 702/703 but we are also gaining .0003 more by our polishing method. In essence a rod that was .001 clearance before with 088-089 can now be installed with the newer polished bearings and be AROUND .0016. Bearings that were in at .0013 should be able to get to .0019. It is not the end all be all but it will help.
Also remember I have one smaple of each bearing. From our experience ther can be +-.0001 from shell to shell. Not every bearing will turn out the same as these measurements. Here are some pics for comparison. I did not do pictures of the before polishing sizes, they were measured but not photographed.

[aus]

Thanks Kawasaki.
How does your polishing compare to the WPC process AutoTalent had used on their bearings that apparently may have increased clearances too?

Is a harder bearing a good thing or a bad thing?

Thanks again.

.

[klammer]

Would it make sense to switch oils depending on the season? Am in Chicago so winters get pretty cold, but in the summer its hot and I track quite a bit...also, is there any risk in preventative switching out OEM for OEM of the bearings?? Am worried I've had no problems, replace the bearings, and the new ones don't match as well or they create a clearance issue where one never existed before...does that make sense? Also, haven't heard enough about the statistical probability of these events and how much tech and engineering improves and that clearances may or may not be changing over time...I plan on doing a winter refresh with the car and am just running down the checklist and looks like this will be added...the beauty of science and engineering is that almost nothing is set in stone (thinking larger concepts, not math) , just greater degrees of understanding...thanks for continuing to add to that level of understanding to all

[thekurgan]

You're the man, Kawasaki, for getting this data. In your opinion, are bearings with harder surfaces more likely to score the crank, instead of being a consumable on the cheaper, more serviceable bearing? Just curious, seems there's always a catch

[Malek@MRF]

For those wondering on the usage of 0W-40 Mobil1 oil:

This past weekend the M3 went to WSIR Big Willow and ran multiple 30 minute sessions with no stops during the sessions lapping 1:33.xx to 1:35.xx all day. Weather was approximately 76*F.

The Oil Pressure did not vary from stock much at all, at least not an appreciable difference to be of concern, the values were still within BMW specifications of where the oil pressure should be operating.

Oil Temperatures. The temperature of the oil never exceeded 225*F (slightly past the half way point on the cluster gauge) surprisingly. Another fact to note, in a slightly cooler climate at the same track with TWS 10W-60, the car run much hotter oil temps (slightly past the 3rd marking for those who want a reference point). During cool down laps, oil temperature also lowered noticeably faster than they did with the 10W-60.

This M3 will remain on 0W-40 Mobil1 during a hotter event, and will report back once again, however I expect it to be equally impressive in less ideal ambient conditions as well.

-Malek

[BMRLVR]

Originally Posted by Malek@MRF

For those wondering on the usage of 0W-40 Mobil1 oil:

This past weekend the M3 went to WSIR Big Willow and ran multiple 30 minute sessions with no stops during the sessions lapping 1:33.xx to 1:35.xx all day. Weather was approximately 76*F.

The Oil Pressure did not vary from stock much at all, at least not an appreciable difference to be of concern, the values were still within BMW specifications of where the oil pressure should be operating.

Oil Temperatures. The temperature of the oil never exceeded 225*F (slightly past the half way point on the cluster gauge) surprisingly. Another fact to note, in a slightly cooler climate at the same track with TWS 10W-60, the car run much hotter oil temps (slightly past the 3rd marking for those who want a reference point). During cool down laps, oil temperature also lowered noticeably faster than they did with the 10W-60.

This M3 will remain on 0W-40 Mobil1 during a hotter event, and will report back once again, however I expect it to be equally impressive in less ideal ambient conditions as well.

-Malek

Good info! Much as I expected to be honest.

[kawasaki00]

Originally Posted by thekurgan

You're the man, Kawasaki, for getting this data. In your opinion, are bearings with harder surfaces more likely to score the crank, instead of being a consumable on the cheaper, more serviceable bearing? Just curious, seems there's always a catch

Originally Posted by aus

Thanks Kawasaki.
How does your polishing compare to the WPC process AutoTalent had used on their bearings that apparently may have increased clearances too?

Is a harder bearing a good thing or a bad thing?

Thanks again.

.

The harder the bearing the more of a beating it can take before it starts to degrade. You are right there is a catch to the hard bearing. Once it starts to go it will tear the journal up easier and make a full on rebuild more likely. The softer lead bearing is much easier on the crank but seems to be more susceptible to breaking apart faster.
Unfortunately I cant really talk about what was done to the polished bearing though. I will say it is a different process than the WPC, not better just different.
If the clearance can be brought up to a more acceptable level with the newer bearings then I would not have a problem running them. I do how ever have a problem running the harder bearing when the clearance is tight. IMHO this is part of why the newer 2011 and forward cars are more likely to kick the rods out during that first 25/30k miles. At least with the softer bearing it will be much more forgiving if it is tight.

[regular guy]

Originally Posted by kawasaki00

Regular Guy was gratious enough to send me bearings to look at and measure and hardness test.
What has been observed is the original 088/089 bearings are a copper/lead content while the 702/703 bearings are of an aluminized tin/silicon compound.
Measurements with my mic are as follows, I am in no way saying what is right or wrong but there is always a tenth or two between different people, just because I measure one way is not to say another measurement is incorrect. What matters is the same guy measuring the crank and the clearance for the final outcome.
088 .07875
089 .07885
091 .0837
090 .0836
702 .07855
703 .07875
Measurements are pretty much in line with what others have documented up until they get polished.
What is a MASSIVE change is the hardness of the bearings. I will not get into the difference of what is right or wrong here but just know the new 702/703 bearings are a huge jump in hardness
The average hardness for the 088/089 bearings are the same at 16.2B Scale
The average hardness for the 702-703 bearings are the same at 61.8B Scale

This puts to rest the theory that one bearing is harder than the other relative to the old vs new ones.
We can work bearings to get a few tenths when needed at our shop. The big one here is not only are we gaining on the average .0002-.0003 by going to the 702/703 but we are also gaining .0003 more by our polishing method. In essence a rod that was .001 clearance before with 088-089 can now be installed with the newer polished bearings and be AROUND .0016. Bearings that were in at .0013 should be able to get to .0019. It is not the end all be all but it will help.
Also remember I have one smaple of each bearing. From our experience ther can be +-.0001 from shell to shell. Not every bearing will turn out the same as these measurements. Here are some pics for comparison. I did not do pictures of the before polishing sizes, they were measured but not photographed.

Originally Posted by BMRLVR

Good info! Much as I expected to be honest.

Originally Posted by kawasaki00

The harder the bearing the more of a beating it can take before it starts to degrade. You are right there is a catch to the hard bearing. Once it starts to go it will tear the journal up easier and make a full on rebuild more likely. The softer lead bearing is much easier on the crank but seems to be more susceptible to breaking apart faster.
Unfortunately I cant really talk about what was done to the polished bearing though. I will say it is a different process than the WPC, not better just different.
If the clearance can be brought up to a more acceptable level with the newer bearings then I would not have a problem running them. I do how ever have a problem running the harder bearing when the clearance is tight. IMHO this is part of why the newer 2011 and forward cars are more likely to kick the rods out during that first 25/30k miles. At least with the softer bearing it will be much more forgiving if it is tight.

Thank you guys so much for helping with this discussion. We really moved this issue forward and helped educate a lot of people. There's always going to be those who don't want to accept the conclusions. Maybe in time, they will...we shall see.

As time permits, I'll keep updating this thread with new bearing pictures. I still have many more sets to post, but so little time to do it.

[FogCityM3]

Awesome real-world feedback- very helpful, thx

Originally Posted by Malek@MRF

For those wondering on the usage of 0W-40 Mobil1 oil:

This past weekend the M3 went to WSIR Big Willow and ran multiple 30 minute sessions with no stops during the sessions lapping 1:33.xx to 1:35.xx all day. Weather was approximately 76*F.

The Oil Pressure did not vary from stock much at all, at least not an appreciable difference to be of concern, the values were still within BMW specifications of where the oil pressure should be operating.

Oil Temperatures. The temperature of the oil never exceeded 225*F (slightly past the half way point on the cluster gauge) surprisingly. Another fact to note, in a slightly cooler climate at the same track with TWS 10W-60, the car run much hotter oil temps (slightly past the 3rd marking for those who want a reference point). During cool down laps, oil temperature also lowered noticeably faster than they did with the 10W-60.

This M3 will remain on 0W-40 Mobil1 during a hotter event, and will report back once again, however I expect it to be equally impressive in less ideal ambient conditions as well.

-Malek

[e92zero]

Originally Posted by kawasaki00

The harder the bearing the more of a beating it can take before it starts to degrade. You are right there is a catch to the hard bearing. Once it starts to go it will tear the journal up easier and make a full on rebuild more likely. The softer lead bearing is much easier on the crank but seems to be more susceptible to breaking apart faster.
Unfortunately I cant really talk about what was done to the polished bearing though. I will say it is a different process than the WPC, not better just different.
If the clearance can be brought up to a more acceptable level with the newer bearings then I would not have a problem running them. I do how ever have a problem running the harder bearing when the clearance is tight. IMHO this is part of why the newer 2011 and forward cars are more likely to kick the rods out during that first 25/30k miles. At least with the softer bearing it will be much more forgiving if it is tight.

Thank you so much for the info. Would it be possible for us to get these polished bearings through you? If we are able to get these bearings or the WPC ones, would you still recommend going to 0-40 or stick to the TWS with the larger clearance bearings?

[swamp2]

So is this accurate?:

-There are 6 different bearings. Are the adjacent numbers a top/bottom set?
-BMW slightly loosened bearing clearances and made the bearings much harder when implementing new lead free bearings? This happened in 2011 model cars?

What is the deal with the way thicker 090/091 bearings?

Originally Posted by kawasaki00

What is a MASSIVE change is the hardness of the bearings. I will not get into the difference of what is right or wrong here but just know the new 702/703 bearings are a huge jump in hardness

It's obviously very interesting to the vast majority of us as to which material/hardness you believe is right and which is wrong. It is pretty amazing that BMW has speced radically differing hardnesses in the exact same application with only a couple of tenths of size difference.

[OM VT3]

what oil would be best for me to use on a supercharged car?

i change oil every 5000kms

[regular guy]

Originally Posted by swamp2

So is this accurate?:

-There are 6 different bearings. Are the adjacent numbers a top/bottom set?

088/089 is bottom/top
090/091 is bottom/top for oversize (first crank regrind)
702/703 is bottom/top for lead-free bearings

[/quote]-BMW slightly loosened bearing clearances and made the bearings much harder when implementing new lead free bearings? This happened in 2011 model cars?[/quote]

Not sure which model year the changes were made. We will track this as more motors are disassembled.

What is the deal with the way thicker 090/091 bearings?

First oversize (first crank regrind).

It's obviously very interesting to the vast majority of us as to which material/hardness you believe is right and which is wrong. It is pretty amazing that BMW has speced radically differing hardnesses in the exact same application with only a couple of tenths of size difference.

Note: When I measured the 702/703's, they measured the same thickness as 088/089's, but kawasaki got slightly different measurements -- a few tenths difference. I know I torqued both of them into a connecting rod to measure the bore diameter -- but I don't remember if I posted the results...and I don't remember off the top of my head what they were.

[thekurgan]

Originally Posted by kawasaki00

The harder the bearing the more of a beating it can take before it starts to degrade. You are right there is a catch to the hard bearing. Once it starts to go it will tear the journal up easier and make a full on rebuild more likely. The softer lead bearing is much easier on the crank but seems to be more susceptible to breaking apart faster.
Unfortunately I cant really talk about what was done to the polished bearing though. I will say it is a different process than the WPC, not better just different.
If the clearance can be brought up to a more acceptable level with the newer bearings then I would not have a problem running them. I do how ever have a problem running the harder bearing when the clearance is tight. IMHO this is part of why the newer 2011 and forward cars are more likely to kick the rods out during that first 25/30k miles. At least with the softer bearing it will be much more forgiving if it is tight.

It surely makes sense with the same tolerances with the new bearing material. It's too bad the wear on the original bearing isn't more uniform, it may have increased tolerances "naturally" and allowed the 60 weight to do its job.

[thekurgan]

Originally Posted by BMRLVR

Good info! Much as I expected to be honest.

Agree. The thinner oil should be able to release heat better than the thicker oil. Those running will also probably notice when the oil temp rises, it also falls quicker as well.

[saxonb]

Originally Posted by swamp2

So is this accurate?:

-There are 6 different bearings. Are the adjacent numbers a top/bottom set?
-BMW slightly loosened bearing clearances and made the bearings much harder when implementing new lead free bearings? This happened in 2011 model cars?

What is the deal with the way thicker 090/091 bearings?



It's obviously very interesting to the vast majority of us as to which material/hardness you believe is right and which is wrong. It is pretty amazing that BMW has speced radically differing hardnesses in the exact same application with only a couple of tenths of size difference.

also 3x different cranks

[speedaddictM3]

So if I get this right BMW tried to solve the problem but only made it worse? So the harder 702/703 bearings wear a bit slower but destroy the engine when they do? My car is a 2008 model so I assume I have the softer 088/089 lead bearings.

[BuckRodgers]

Originally Posted by speedaddictM3

So if I get this right BMW tried to solve the problem but only made it worse? So the harder 702/703 bearings wear a bit slower but destroy the engine when they do? My car is a 2008 model so I assume I have the softer 088/089 lead bearings.

What will or will not happen at this point is pure speculation until real world data is collected over time. The only facts we have is that bearings were changed to provide a more durable surface and BMW knows that the TWS oil is not the only oil that can or should be used in the S65 motor. Most of the people I talk to who race say that TWS oil is shit. I have switched recently as my car is on the track several times a year. One of the issues with the m3 on the track is oil temp recovery time and hopefully the new oil will help with this.

[thekurgan]

Originally Posted by speedaddictM3

So if I get this right BMW tried to solve the problem but only made it worse? So the harder 702/703 bearings wear a bit slower but destroy the engine when they do? My car is a 2008 model so I assume I have the softer 088/089 lead bearings.

You do.

[MWM3]

so does this mean that my car is going to blow up in the near future?