Official S65 Bearing Specification/Clearance Wiki

[kawasaki00]

Originally Posted by Yono325ic

In my old e30 m20b25 and e36 m50b28 I have used Redline 5W40 and both engines ran a lot quieter. The tappets sounded smoother, and the engine just felt happier at high revs. This was after using mobile 5W30 at the time.
Maybe the BMW engines love the ester base stock oils. Hence why I'm asking is someone could shine some light on the syn/ester topic specific to BMW engines???

BITOG is a good place to learn all about that stuff. Different companies blend differently so it is hard to just have a black and white syn vs ester debate or conversation. And the fact some of them are not always truthful about the base either

[G80indy]

Looking at Redline High Performance oil and Ultra Platinum Pennzoil Euro
I can't see inherent superiority of PUP 0w40
Redline specs NOACK
Pennz does not

[G80indy]

Originally Posted by kawasaki00

Most of the 40wt stuff, including blended ones that are not for sale. I am sure they have things that work for a lot of folks. We have found better though, especially at 400 degrees oil out temp

Better? Do share
(Not enough details here)

[Leonardo629]

Originally Posted by kawasaki00

For the driving you are doing The Belgium Castrol 0-40 would be the best option. It may not be available but try to look for it. NONE of the 5-50s are really that good. They cant hold that film strength long term. A 10-50 can hold the 50wt number longer but it is also a 10wt base so that may not work for you.
Never been a fan of the Redline stuff, we have ran it in motorsports world and just could never get it to work. It is high in NOACK so it does coke pistons up more than group 5 oils.
Stay away from the newer Mobil 0-40 FS also, it is not as good as the older stuff.
The Pennzoil 0-40 ultra euro or whatever they call it is really good. But dang is it expensive. Super low in Noack and it is one of the only oils that we have tried that continuously seems to have less consumption than the rest.

Kawasaki, care to elaborate on the "stay away from the newer 0W40 FS" part? I've been using nothing but M1 0W40 in my M3 since I picked it up back in '13, so of course it has the latest FS oil in the engine right now.

I've supplied BITOG with a VOA on the 0W40 FS, and I also did a 4000mi UOA on the same stuff, the result? Super stable viscosity, there's virtually no change after 4000mi of use, which I believe is the strength of the gas-to-liquid basestock, but what do I know?

[IamFODI]

(Apologies if I missed this somewhere in the thread)

May I ask Regular Guy or Kawasaki00 to comment on how the 702/703 bearings were determined to be Al/Sn/Si? Wondering if you have any info on the exact alloy used, the percentages of each element, or anything that might help track that info down. I asked Glyco a related question and they didn't want to say anything, at least to me.

[Green-Eggs]

There's a new and "shocking" development for the people following this thread and the BMW S65 rod bearing issue. After 10+ years, BMW has finally published their rod bearing clearance specifications. To put it mildly, the specs are shocking and are worse than we had imagined.

Every time a new TIS is published, Bert checks to see if BMW has finally published the rod bearing clearance specs. Such was the case last week when Bert was researching the rod bearing specs for S63 motor. That's when Bert pulled up the S65 engine specs, and noticed that they finally contain rod bearing clearance. [LINK]

The specs aren't good and confirm a worse-than worst case scenario. When Van Dyne measured the original bearings @ 0.0013 inch, they didn't imagine that was at the top end of the clearance specs. Stewart Van Dyne gave the following comment over the phone: "Well, BMW just confirmed that they're doing what we all know doesn't work."

Minimum clearance: 0.0004 inch
Nominal clearance: 0.0009 inch
Maximum clearance: 0.0013 inch

[IamFODI]

Originally Posted by Green-Eggs

There's a new and "shocking" development for the people following this thread and the BMW S65 rod bearing issue. After 10+ years, BMW has finally published their rod bearing clearance specifications. To put it mildly, the specs are shocking and are worse than we had imagined.

Every time a new TIS is published, Bert checks to see if BMW has finally published the rod bearing clearance specs. Such was the case last week when Bert was researching the rod bearing specs for S63 motor. That's when Bert pulled up the S65 engine specs, and noticed that they finally contain rod bearing clearance. [LINK]

The specs aren't good and confirm a worse-than worst case scenario. When Van Dyne measured the original bearings @ 0.0013 inch, they didn't imagine that was at the top end of the clearance specs. Stewart Van Dyne gave the following comment over the phone: "Well, BMW just confirmed that they're doing what we all know doesn't work."

Minimum clearance: 0.0004 inch
Nominal clearance: 0.0009 inch
Maximum clearance: 0.0013 inch

So the obvious question becomes even more salient: Why?

If it's true that tight rod bearing clearance was a mistake on this engine, this development means the mistake was even greater than previously believed. That makes it even harder to escape the binary choice: either the M Division was spectacularly incompetent here, neglecting or forgetting noob-level basics of engine building, or there's something -- something -- that explains their choice.

[Green-Eggs]

Originally Posted by IamFODI

So the obvious question becomes even more salient: Why?

If it's true that tight rod bearing clearance was a mistake on this engine, this development means the mistake was even greater than previously believed. That makes it even harder to escape the binary choice: either the M Division was spectacularly incompetent here, neglecting or forgetting noob-level basics of engine building, or there's something -- something -- that explains their choice.

Some people just think they're smarter than everybody else. It can be as simple as the difference between what they learned in school vs. what they learned in real life. Maybe the books said they could do this, but in real life...it doesn't work.

[Nebo]

Is it possible the tolerances were carried over from F1 back in the day? I don't understand how something like that would have been missed during the design/review process....like all the people signing off on everything.

[Helmsman]

Originally Posted by Green-Eggs

There's a new and "shocking" development for the people following this thread and the BMW S65 rod bearing issue. After 10+ years, BMW has finally published their rod bearing clearance specifications. To put it mildly, the specs are shocking and are worse than we had imagined.

Every time a new TIS is published, Bert checks to see if BMW has finally published the rod bearing clearance specs. Such was the case last week when Bert was researching the rod bearing specs for S63 motor. That's when Bert pulled up the S65 engine specs, and noticed that they finally contain rod bearing clearance. [LINK]

The specs aren't good and confirm a worse-than worst case scenario. When Van Dyne measured the original bearings @ 0.0013 inch, they didn't imagine that was at the top end of the clearance specs. Stewart Van Dyne gave the following comment over the phone: "Well, BMW just confirmed that they're doing what we all know doesn't work."

Minimum clearance: 0.0004 inch
Nominal clearance: 0.0009 inch
Maximum clearance: 0.0013 inch

Thanks Green-Eggs, how interesting! Yeah certainly seems to be on the (extremely) tight side and assumingly a good reason to the wear issues we see. BMW engineering certainly been around so bit of a mystery.

These numbers also make me curious about your own measurement of BMWs shell which comes out with quite a bit more clearance?

Nominal Rod Bearing Clearance 0.0381mm
Bearing Clearance Variance 0.0292 - 0.0508mm

Just trying to understand what we're comparing here.

Thanks

[CSBM5]

Originally Posted by Helmsman

Thanks Green-Eggs, how interesting! Yeah certainly seems to be on the (extremely) tight side and assumingly a good reason to the wear issues we see. BMW engineering certainly been around so bit of a mystery.

These numbers also make me curious about your own measurement of BMWs shell which comes out with quite a bit more clearance?

Nominal Rod Bearing Clearance 0.0381mm
Bearing Clearance Variance 0.0292 - 0.0508mm

Just trying to understand what we're comparing here.

Thanks

Yeah, me too. That was my first thought - about how the measured "as built" values were significantly looser than this so-called spec. I say "so-called" since it wouldn't be the first time BMW published inaccurate information.

[Green-Eggs]

Originally Posted by Helmsman

Thanks Green-Eggs, how interesting! Yeah certainly seems to be on the (extremely) tight side and assumingly a good reason to the wear issues we see. BMW engineering certainly been around so bit of a mystery.

These numbers also make me curious about your own measurement of BMWs shell which comes out with quite a bit more clearance?

Nominal Rod Bearing Clearance 0.0381mm
Bearing Clearance Variance 0.0292 - 0.0508mm

Just trying to understand what we're comparing here.

Thanks

(Same response as other thread)

This is just the data, no other comparisons are implied. We'll leave that to others to discuss and debate.

One thing about those numbers, you' pulled them from the 702 bearings, not the 088 bearings. Since these specs just appeared 10+ years later, we have no idea whether they are for both bearings or not. My personal opinion is that the specs between 088 and 702 bearings didn't change. I know that goes against the general opinions of others. I think those measurement differences are rather insignificant. 0.5/10000 to 2/10000 of an inch difference between paper specs and measured specs is pretty insignificant IMO.

[Green-Eggs]

Originally Posted by CSBM5

Yeah, me too. That was my first thought - about how the measured "as built" values were significantly looser than this so-called spec. I say "so-called" since it wouldn't be the first time BMW published inaccurate information.

The differences are between 0.5/10000 to 2/10000. That's quite insignificant IMO. The difference becomes even less if Bert had used "AVERAGE" instead of "MODE" to calculate the nominal values. Bert told me that 'swamp' told him MODE was the better way. Using AVERAGE, the nominal clearance would be 0.0014 inch -- only 1/10000 different. But again, these differences are so small, they are insignificant IMO.

[Brandoch]

Use this thread for technical, and engineering discussions.

[Green-Eggs]

Here's the latest find on clearance info.

[PaulGros]

Originally Posted by Green-Eggs

Here's the latest find on clearance info.

Are you now going to update the WIKI with the official BMW service specifications?

I note when I published the specs from the drawing it was noted as "credible but unverified" The data I published is contained in an official MAHLE technical bulletin and states "The Trento bearing drawing specified a total clearance range of 0.029mm to 0.062mm which gives a mean clearance of 0.046mm."

MAHLE purchased Glacier Vandervell who produced the OE bearing in Trento, Italy (not Clevite as stated) and the data comes from their OE drawing. I'm wondering what information has to be provided for it to be verifiable? The MAHLE document can be found here https://marmotorsport.com/wp-content...S85-Iss.-2.pdf

There are now TWO pieces of data in the public domain, one from BMW and one from the real original bearing manufacturer that go against the claims in the wiki of BMW clearance specs. Both show that the clearance for the S65 / S85 is completely in line with other BMW rod bearings clearances.

[Green-Eggs]

Originally Posted by PaulGros

Are you now going to update the WIKI with the official BMW service specifications?

I grabbed it from the wiki, and posted it here, but I think it was only added two days ago.

I note when I published the specs from the drawing it was noted as "credible but unverified" The data I published is contained in an official MAHLE technical bulletin and states "The Trento bearing drawing specified a total clearance range of 0.029mm to 0.062mm which gives a mean clearance of 0.046mm."

Is this an actual technical bulletin from Mahle, separate from the technical document that you posted from Mahle Motorsport? It would be nice to see that as well.

MAHLE purchased Glacier Vandervell who produced the OE bearing in Trento, Italy (not Clevite as stated) and the data comes from their OE drawing. I'm wondering what information has to be provided for it to be verifiable? The MAHLE document can be found here https://marmotorsport.com/wp-content...S85-Iss.-2.pdf

I can speak for myself because I believe that I posted the comment about "credible but unverified." Posting a document that contains a quote that can't be verified independently is what I was talking about. Maybe you and Bert can discuss and figure something out. He told me that you two have been chatting and that he's in the process of improving the wiki. I think that's when he posted this updated info because looking at the page history, it says it was added two days ago.

There are now TWO pieces of data in the public domain, one from BMW and one from the real original bearing manufacturer that go against the claims in the wiki of BMW clearance specs. Both show that the clearance for the S65 / S85 is completely in line with other BMW rod bearings clearances.

I wouldn't expect the measured results at the wiki to change unless the measurements with the new equipment change. However, if you have your own measured results, then this would be the thread to post them.

BTW, did you see the comments only a few posts above about using MODE instead of AVERAGE? IIRC, the guy "swamp" referred in that post is a statistician by trade. If you wade through this thread, you'll see his participation and disagreements in plenty of places.

[PaulGros]

Originally Posted by Green-Eggs

I grabbed it from the wiki, and posted it here, but I think it was only added two days ago.

The WIKI has been updated, but is still showing the incorrect specs 0.0004" - 0.0013" as per attached image.

On the WIKI update you are also quoting data from MAHLE Motorsport from Berts visit (incorrectly) as relevant to the OE bearings. i.e. rockwell hardness.

The following statement is also completely wrong "The combination of a lead tin alumina overlay with VP2 improves wear resistance by a factor of two when compared with a lead tin copper overlay"

I believe the confusion here arises from BE V2 bearings which are Clevite F material, which is MCB2 base (cast lead copper i.e.bronze), nickel barrier layer and lead, indium , tin with alumina (aluminium oxide) overlay, not silver oxide.

Originally Posted by Green-Eggs

Is this an actual technical bulletin from Mahle, separate from the technical document that you posted from Mahle Motorsport? It would be nice to see that as well.



I can speak for myself because I believe that I posted the comment about "credible but unverified." Posting a document that contains a quote that can't be verified independently is what I was talking about. Maybe you and Bert can discuss and figure something out. He told me that you two have been chatting and that he's in the process of improving the wiki. I think that's when he posted this updated info because looking at the page history, it says it was added two days ago.

So a world renowned and respected manufacturer that is active in ALL motorsport from F1 down produces a technical bulletin stating the OEM clearances, calculated from the OEM drawing with the OEM development data that they have as they purchased the company that produced the OEM parts and you want more proof? Yet if I question the logic posted about requiring an additional .005" clearance I'm pointed to the ACL catalogue?

You misquote the Clevite paper stating that .001" per inch of journal is "industry standard" when it actually states “For most applications .00075 to .0010” (three quarters to one thousandth of an inch) of clearance per inch of shaft diameter is a reasonable starting point” Which incidentally is exactly where the now released data (from 2 sources) puts the OEM bearings, yet you question the validity of the MAHLE data?

Please, have the same standards of scrutiny over data that appears to agree with your claims as the data that appears to disagree.

Originally Posted by Green-Eggs

I wouldn't expect the measured results at the wiki to change unless the measurements with the new equipment change. However, if you have your own measured results, then this would be the thread to post them.

BTW, did you see the comments only a few posts above about using MODE instead of AVERAGE? IIRC, the guy "swamp" referred in that post is a statistician by trade. If you wade through this thread, you'll see his participation and disagreements in plenty of places.

Your measured clearances don't align with your wall thickness measurements.

I have checked the claim on mode vs mean across all your data (yes, I am that sad!) Here are my results

ACL H - Mode is used
ACL HX - Mode is used
VAC Clevite - Mode is used
BE V1 - Mode is used
BE V2 - MEAN is used
088 /089 - cannot correlate claimed clearance to mode or mean
702 / 703 - cannot correlate claimed clearance to mode or mean

So no consistency.

More interestingly the BE V2 clearance claimed as well as mode clearance or mean clearance is not theoretically possible with the wall thickness span quoted and the crank data used. And none of these marry up to the .0024" claimed elsewhere on the forum.

Bert is aware of my concerns and what I personally consider to be pretty fundamental errors in the WIKI. Unless you can independently verify the measurement data, why should I trust this, especially when it doesn't marry with the wall thickness measurements also taken and published?

[Scharbag]

Originally Posted by PaulGros

The WIKI has been updated, but is still showing the incorrect specs 0.0004" - 0.0013" as per attached image.

On the WIKI update you are also quoting data from MAHLE Motorsport from Berts visit (incorrectly) as relevant to the OE bearings. i.e. rockwell hardness.

The following statement is also completely wrong "The combination of a lead tin alumina overlay with VP2 improves wear resistance by a factor of two when compared with a lead tin copper overlay"

I believe the confusion here arises from BE V2 bearings which are Clevite F material, which is MCB2 base (cast lead copper i.e.bronze), nickel barrier layer and lead, indium , tin with alumina (aluminium oxide) overlay, not silver oxide.



So a world renowned and respected manufacturer that is active in ALL motorsport from F1 down produces a technical bulletin stating the OEM clearances, calculated from the OEM drawing with the OEM development data that they have as they purchased the company that produced the OEM parts and you want more proof? Yet if I question the logic posted about requiring an additional .005" clearance I'm pointed to the ACL catalogue?

You misquote the Clevite paper stating that .001" per inch of journal is "industry standard" when it actually states “For most applications .00075 to .0010” (three quarters to one thousandth of an inch) of clearance per inch of shaft diameter is a reasonable starting point” Which incidentally is exactly where the now released data (from 2 sources) puts the OEM bearings, yet you question the validity of the MAHLE data?

Please, have the same standards of scrutiny over data that appears to agree with your claims as the data that appears to disagree.



Your measured clearances don't align with your wall thickness measurements.

I have checked the claim on mode vs mean across all your data (yes, I am that sad!) Here are my results

ACL H - Mode is used
ACL HX - Mode is used
VAC Clevite - Mode is used
BE V1 - Mode is used
BE V2 - MEAN is used
088 /089 - cannot correlate claimed clearance to mode or mean
702 / 703 - cannot correlate claimed clearance to mode or mean

So no consistency.

More interestingly the BE V2 clearance claimed as well as mode clearance or mean clearance is not theoretically possible with the wall thickness span quoted and the crank data used. And none of these marry up to the .0024" claimed elsewhere on the forum.

Bert is aware of my concerns and what I personally consider to be pretty fundamental errors in the WIKI. Unless you can independently verify the measurement data, why should I trust this, especially when it doesn't marry with the wall thickness measurements also taken and published?

Love all the math stuff - but a physics prof once told me that reality always trumps theory.

At the end of the day, I find this graphic provides more real data than all of the theoretical discussions:



If BMW got the design right, why is the oil flow so low with the factory bearings (especially near red line)?

Cheers,

[PaulGros]

Originally Posted by Scharbag

Love all the math stuff - but a physics prof once told me that reality always trumps theory.

At the end of the day, I find this graphic provides more real data than all of the theoretical discussions:



If BMW got the design right, why is the oil flow so low with the factory bearings (especially near red line)?

Cheers,

I'd say they're both relevant.

Firstly I'm struggling to see how bearings can give extra clearance when the measured and published figures put the wall thickness inline with OEM / others?

So that then raises the question on why there is an oil flow difference, particularly on an engine with a controlled pump that varies flow? As far as I am aware, the oil pressure and flow data was measured in total, not just for the bearing feed. So, if I am going to be pedantic, that then also raises the question of how you know the oil flow to the bearings was lower when only total engine flow was measured?

[Helmsman]

Originally Posted by PaulGros

I'd say they're both relevant.

Firstly I'm struggling to see how bearings can give extra clearance when the measured and published figures put the wall thickness inline with OEM / others?

So that then raises the question on why there is an oil flow difference, particularly on an engine with a controlled pump that varies flow? As far as I am aware, the oil pressure and flow data was measured in total, not just for the bearing feed. So, if I am going to be pedantic, that then also raises the question of how you know the oil flow to the bearings was lower when only total engine flow was measured?

Like Scharbag says reality trumps theory, for one specific engine.

However I’ve also been curious over suggesting general clearance based on measurements on a specific set of surrounding hardware. For data to be general applicable – within given tolerances – one can't imo avoid theory/calculations.

Paul, believe you have ran clearance for a few of discussed rod shells, would be interesting if you are able to share the numbers for continued discussions.

[PaulGros]

Originally Posted by Helmsman

Like Scharbag says reality trumps theory, for one specific engine.

However I’ve also been curious over suggesting general clearance based on measurements on a specific set of surrounding hardware. For data to be general applicable – within given tolerances – one can't imo avoid theory/calculations.

Paul, believe you have ran clearance for a few of discussed rod shells, would be interesting if you are able to share the numbers for continued discussions.

I've been compiling data on all available S65 bearings. Currently a lot of the information is very confusing, particularly around the area of claimed clearance. This is compounded by the fact that each manufacturer is calculating using marginally different crank & housing data.

The theory is pretty basic maths, based on housing size, crank size and bearing wall thickness. If you run the theory with manufacturer specs for the bearings and with OEM crank & housing data (which I have from the OE drawing) then all bearings are remarkably similar in clearance, including OEM.

You can do the same with the min & max measured wall thickness from the WIKI with similar results. In this respect the theoretical and the measured clearances are not quite adding up. I have spoken to BE about clarifying some of the data, so I'll refrain from posting actual numbers at the moment.

The other anomaly with the theoretical clearances is tolerance. It is standard for any bearing manufacturer to publish their max wall thickness, so anyone can calculate the minimum clearance. However, if a manufacturer allows a wide tolerance from this max figure it can also appear that they have more clearance by design, when I fact they are showing a higher figure as they are accepting a wider deviation on wall thickness in production.

For the bearings available in the market we are seeing measured deviations from around 3um to almost 13um between differerent brands. 13um seems particularly high. For example, we know that MAHLE print data is 9um and from measured data they are achieving 6um.

I'll try and find a little time in the coming days to post wall data frok various brands, both published and measured. What we really need is print data for all parts and then calculate with a standard set of housing / crank data to give clarity where each brand is targeting.