Con rod bearings - Munich Legends

ronk said:
I thought these engines were durable?
Replacing the big end shells at 50k seems low - assuming the service regime has been followed.
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How do you know how cars have been driven? Thrashed from cold / tracked etc.

I'm sure there are plenty out there that have hit 100k no problem.
 
i actually don't think it is.... its a highly strung engine, relatively low capacity with a high rev limit, these are a side product of that, cold thrashing can't be the cause of pretty much every single n/A high revving ///M engine of the past 15 years, which all seem to have the same rod bearing weakness.

Great price and something i consider a maintenance item on this engine, as it is on the s65, s85, s54, s14.........
 
My Dad is a retired Moto GP mechanic and he still rebuilds bike engines for mates / Padgetts and I was talking to him about this the other week.

Oddly he'd just got a Padgetts race engine in that needed a new Conrod due to a spun bearing.

I'd imagine those things are warmed up properly before thrashing.
 
DPG said:
My Dad is a retired Moto GP mechanic and he still rebuilds bike engines for mates / Padgetts and I was talking to him about this the other week.

Oddly he'd just got a Padgetts race engine in that needed a new Conrod due to a spun bearing.

I'd imagine those things are warmed up properly before thrashing.
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we are talking about entirely different engines... it can't be the cause in the vast amount of SXX engines showing significant RB wear that they are all being thrashed from cold (maybe a % but not this consistent number from pretty much all the last 15 years of S derivative engine) .... maybe we just need to accept that BMW deem this item as a maintenance part and designed them as such, its been going on too long to not see it any other way now, i mean the ///M devision know how to build a motor.
 
Exactly. My car spent most its life in Bristol, hardly the sort of place you would be able to consistently thrash a car from cold.
Just waiting at Munich to drive it home.
Excited!
 
Yorkie Z said:
2dogs said:
How can you tell if their on the way out. :scratchhead:
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That's the problem, you can't :(
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I would have thought that deteriorating she'll bearings could be diagnosed from having an oil analysis carried out, the excess copper/nickel etc from the shells should stand out a mile from a healthy engine reading?
Regards
 
Forums in US always discussing oil analysis, then others say they did, but still had failure. Interesting, though perhaps obvious, top shells more worn than bottom and it appears they may well have failed at some point.
Good for another 50k miles
 
Does the oil pressure at tickover not drop - or is the pump man enough to compensate ?

Did you get any photographs - I'd be interested to see what the deterioration of the shells look like.
 
autobahner said:
Forums in US always discussing oil analysis, then others say they did, but still had failure. Interesting, though perhaps obvious, top shells more worn than bottom and it appears they may well have failed at some point.
Good for another 50k miles
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Top shells failing does sound like ( I've not seen the pictures) a lubrication failure. However the top shells will always see more load ie. From the big bang that happens above along with the compression loadings.
 
check out these from s65.... good lawd... engine made its highest ever power figure on these bearings!! lol.. their RB issue seems even worse than the s54,


http://www.m3post.com/forums/showthread.php?t=1227119
 
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