BMW (finally) publishes S65 Rod Bearing Clearance Specs

[Assimilator1]

Originally Posted by e46e92love

Yeah, I’m not sure why you did either.

I make it simple, and I know everyone will flame me for this, and this is not a shot at your questions or anyone else’s: take total production numbers, then take total engine failures from STOCK vehicles (meaning never tuned or SC) and I bet the MTF is better than most cars and undefeated against any other engine that revs to 8300 rpm’s while being more than capable of running past 100k miles without being rebuilt.

Sorry, BMW gave us a gem, some found ways to piss all over it for mythical rod bearing and low torque arguments and here we are: with boring, automatic driven turbo engines with as much personality as a dead donkey.

Just my .02. Don’t miss the drama from these forums that seemed to rule this place from 2007-2018.

Cheers,
e46e92

No flaming intended here, but I will argue you!
Re MTF, err no, do a simple little exercise, Google rod bearing failure for Honda S2000s (which their engines rev to 8.2k or 9k RPM! Depending on which version) and you'll find precious few hits, most of which will have other causes, e.g oil pump failure. Btw that engine has more hp/ltr than the S65.
I understand you'll find similarly low hits for the Audi R8 too, but I haven't tried that myself.
Now try that search for the S65, you'll get much more hits!

There's nothing mythical about the rod bearing problem, there's clear evidence of that now in the rod bearing condition thread where several hundred sets of pulled rod bearing photos have been posted, with roughly 1/2 of them showing severe wear and nearly all of the other 1/2 showing moderate to significant wear, and only about 2% of them showing almost no wear (as they ought to be!).

You can, and we certainly still do argue as to what is the cause/causes, but there's no question now that there is a problem with them, especially the earlier lead/copper ones, but the later ones aren't immune
either.

I do agree though about the silly statements about it lacking torque, some people just don't seem to understand it, that is.
A. It's a 4 ltr engine, not a 5,6 or 7 ltr as many US V8s are.
B. It's a high power NA engine which means it needs to rev high for that high power, which means it's torque spread will be further up the rev range.

I think the S65 is a fantastic engine, just that it has a couple of flaws, the rod bearings and TAs.
But it's got brilliant throttle response, fantastic induction sound, awesome sounding exhaust and beautiful linear screaming power delivery!

I would venture to guess it’s because the majority of the wear and tear on the engine comes from cold startup / first start of the day. 10w60 I bet remains on the parts longer after shut down, hence leaving more lubrication on parts leading to lower cold start wear. I think it’s also why the higher mileage cars seem to have LESS problems.

Err, I'm confused by your statement as you seem to be contradicting yourself, maybe you typo'd?
Your first line states that you think that most wear comes on cold start up (your right, it does, and it does for all engines btw).
And your 2nd line says pretty much the opposite.
Anyway, no the thin covering left after engine shut down doesn't do much for cold starting. What counts is having the full flow of oil through the bearings etc.
Engine manufacturers (bar BMW for 2 of the M3s) have moved away from 10w/xx oils over the past 20-30 years, they have moved over to thinner 5w/xx then 0w/xx oils, this is (at least) for 2 main reasons, yes one is for better economy, but the other major factor is that thinner oil will circulate much more quickly though the engine, especially on cold starts, thus protecting the engine sooner.

Higher mileage S65s don't have less problems, excessive bearing wear (or the rarer engine failure) happens at all mileages.
But if you meant engines more generally, yes engines which do more highway driving (hence less cold starts/miles covered) they do have less problems for some types of wear for comparable miles.

[Sneaky Pete]

IIUC the point of specifying 10W60 for the S65 was for the higher film strength at full operating temperature compared to lower weight oils.
Sure the compromise was that the engine required a more gentle warm up than a lighter weight oil such as a 5W30.
While manufacturers are indeed now designing cars to use lower weight oils for economy and lower emissions...it doesn't automatically mean that using a light weight oil for the S65 is a good idea. Especially if you live in a warm climate.

[Assimilator1]

Originally Posted by Sneaky Pete

Given that the RB clearance for the S65 taken from the drawing held at Mahle is completely in line with the clearances given in the Wiki for nearly the whole range of BMW engines listed.
Doesn't that give anyone pause for thought?
Why is it only the S65 that is suffering such high (sometimes catastrophic) RB wear.
Is there no significant difference between the S65 and all the other BMW engines with the same clearance, built in the same BMW factories for the same USA market that could account for it?

I know you know my reply to that from our discussions at m3cutters , but I just want to re-iterate them here.

I think a large part of the problem is still the clearance because of the thick oil used (which hardly any other engine does. I'm still not clear as to how the switch from 5w30 to 10w60 affected the S54), especially at the tighter end of the tolerance range. And it's high revs (which only the S54 comes close to in BMW circles). I do wonder if 5w50 oil would've been a better compromise for them, and halving the service interval to 7.5k/1yr instead of 15k/2yrs.
That and perhaps a little contribution from mild detonation as per Paul Gros's suggestion, and for some engines, cold abuse (but it can't account for all of them!). And as far as the earlier bearings go, perhaps like you said, the earlier bearings have a greater tolerance range?? (bourn out by BE's measurements of some shells).

[Reddevils7]

Originally Posted by DrFerry

5 Centigrade = 41 Fahrenheit

Just to close the loop. Ambient temp 33F. Car sat for 12 hours from last drive in a mainly enclosed parking garage

Updated pics for when she's warmed up. I noticed the car won't check oil level until it's fully warmed up to about 88 C

[Bubbles]

Originally Posted by PaulGros

Around 2010 was the change date from memory. EU mandate banned lead in car production from, I think, 2011.

After this date all OEM / OES bearings were the Glyco lead free parts which superceded the earlier Glacier Vandervell parts containing lead.

MY2011 manufactured after May 2010.

[charliev68]

If I ever get to open up the MBs of an 08-09 s65, I will definitely picture document and see what bearings are in it.

[Assimilator1]

Originally Posted by charliev68

If I ever get to open up the MBs of an 08-09 s65, I will definitely picture document and see what bearings are in it.

Yea that would be very interesting, usually about the only time we see mains is after an engine's seized!

[PaulGros]

Originally Posted by Assimilator1

Yea that would be very interesting, usually about the only time we see mains is after an engine's seized!

I'm happy to post pics of OEM mains if it helps?

[Richbot]

Originally Posted by Assimilator1

I know you know my reply to that from our discussions at m3cutters , but I just want to re-iterate them here.

I think a large part of the problem is still the clearance because of the thick oil used (which hardly any other engine does. I'm still not clear as to how the switch from 5w30 to 10w60 affected the S54), especially at the tighter end of the tolerance range. And it's high revs (which only the S54 comes close to in BMW circles). I do wonder if 5w50 oil would've been a better compromise for them, and halving the service interval to 7.5k/1yr instead of 15k/2yrs.
That and perhaps a little contribution from mild detonation as per Paul Gros's suggestion, and for some engines, cold abuse (but it can't account for all of them!). And as far as the earlier bearings go, perhaps like you said, the earlier bearings have a greater tolerance range?? (bourn out by BE's measurements of some shells).

I have owned my car from new, took really good care of it, and saw what the factory rod bearings looked like when they came out, and I can say with confidence that at least in my one instance, any suggestion that the bearings were fine from the factory is total horseshit, unless the definition is narrowed to "capable of sliding through the 100k mile CPO finish line on fire and upside down" then in that case, yeah I guess they got me all the way to 102,000 miles without seizing the engine, which is the *best case scenario*, worst case being you, your passengers, and anybody in your path when the oil coats your tires all die in a fiery crash

[Assimilator1]

Originally Posted by PaulGros

I'm happy to post pics of OEM mains if it helps?

Used ones?

Interestingly, since I last posted here, I happened to see a Youtube video by M539 pulling a 103k miles S65 apart showing the main bearings!
And he also talks about an interesting theory as to why the No1 is so worn (the others much less so) and why that one is usually the one to go (when they do)(re twin timing chains).

[a5m]

Originally Posted by Assimilator1

Used ones?

Interestingly, since I last posted here, I happened to see a Youtube video by M539 pulling a 103k miles S65 apart showing the main bearings!
And he also talks about an interesting theory as to why the No1 is so worn (the others much less so) and why that one is usually the one to go (when they do)(re twin timing chains).

Yea I found that theory of his interesting too. He claimed the S85 was less prone due to its timing chain setup and lesser tension or something like that. No one talks about it but I guess RBs aren't the last of the S65 being a ticking time bomb story...

[spammysammich]

Originally Posted by a5m

Yea I found that theory of his interesting too. He claimed the S85 was less prone due to its timing chain setup and lesser tension or something like that. No one talks about it but I guess RBs aren't the last of the S65 being a ticking time bomb story...

Not to forget valve springs and fuel injectors. Plenty of ways to trash an engine.

[PaulGros]

Originally Posted by Assimilator1

Used ones?

Interestingly, since I last posted here, I happened to see a Youtube video by M539 pulling a 103k miles S65 apart showing the main bearings!
And he also talks about an interesting theory as to why the No1 is so worn (the others much less so) and why that one is usually the one to go (when they do)(re twin timing chains).

Not really - they were fitted but not run as far as I remember. I can't recall exactly WHY I ended up with them, but they've been sat in my pile of "keep just in case" items.

I'll take a look when I get a few minutes

[Assimilator1]

Ah ok, I'm after pictures of well used bearings really.

Originally Posted by spammysammich

Not to forget valve springs and fuel injectors. Plenty of ways to trash an engine.

Yes, but those are much rarer failures, in the blown engines list, I think there were 2-3 that had suffered broken valve springs and 6 from failed injectors.
Although some people think injector failures are becoming more common, I'm on the fence on that one.

[spammysammich]

Fuel injectors are talked about a lot on the S85 side of things. I believe we run the same injectors or same materials that were not specifically designed for use with high ethanol content fuels. We’ve seen at least 3 people in the last couple years report bore wash or hydrolock. There may be more unreported instances of cylinder wall damage due to injectors or hydrolock that get masked by rod bearing spins. It’s hard to say unless everyone takes the time to run a borescope into their engines.

[Assimilator1]

Originally Posted by spammysammich

Fuel injectors are talked about a lot on the S85 side of things. I believe we run the same injectors or same materials that were not specifically designed for use with high ethanol content fuels. We’ve seen at least 3 people in the last couple years report bore wash or hydrolock. There may be more unreported instances of cylinder wall damage due to injectors or hydrolock that get masked by rod bearing spins. It’s hard to say unless everyone takes the time to run a borescope into their engines.

Where have these 3 cases been reported?
And by high ethanol fuel are you referring to E85?
Here in the UK the highest we have is E10.

[spammysammich]

Originally Posted by Assimilator1

Where have these 3 cases been reported?
And by high ethanol fuel are you referring to E85?
Here in the UK the highest we have is E10.

On this forum. At least 3 in the two years I’ve been part of it. One in Brazil and two in the us. Parse for bore scoring and loss of compression. Any ethanol. I do not believe our fuel systems were meant to be used with ethanol mixed fuel. I hope I’m wrong but the time frame in which these engines were created predates wide spread adoption of ethanol blends.

[Assimilator1]

I don't believe E5 or E10 is a problem, and IIRC BMW says that E10 is ok with our cars (M3s).
Re the 3 cases you've seen, were they S85s or S65s?

[spammysammich]

S65. One of the members is pretty active, the guy from Brazil. jvictormp

[Assimilator1]

Ah yea, I know that one, and added it to the blown engine list (in my sig).
Can you remember the other 2? (are they already in my list?).

[Green-Eggs]

Originally Posted by Adam M

The key point is that the numbers that started this thread are definitely the correct ones for con rod play and con rod play is very much not the same as clearance.

The original link is now dead, so it's not possible to see how it was defined. Can you site a document source to confirm that it is "con rod play" and post a link so that it can be verified? And by con rod play, do you mean side clearance? The numbers above are definitely not side clearance, because side clearance numbers are approximately 10x larger than bearing/journal clearance numbers. That's why it's important to see a document source, not word-of-mouth.

[Assimilator1]

I've seen the same specs as you posted in the op on BMW's AIR, their is no clarification of what that con rod play refers to (I could post a screenshot of that if you want, but their is no more info, so not much help).

But going by Paul G's data, whatever BMW's conrod play refers to, it is not rod bearing clearance.
Other people believe it to be something else based on similar data layouts for other BMW engines, I'm not sure what though (I've PM'd one of the to ask).