Blown motors, Rod Bearing failure S65 Registry.

[spammysammich]

Originally Posted by Assimilator1

And another S65 failure , posted at the UKM3V8 group - https://www.facebook.com/groups/bmwm...3606372017292/
What we do know is that it had the rod bearings replaced 10k miles ago, but we don't know what type.

No details yet as he hasn't had it stripped down. Thanks to Smuler at m3cutters for alerting me to this one.

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Btw, I'm contemplating starting an entirely new thread for this as I recently found out that a very regular member here wasn't aware of my clean up and categorisation of the ops list, even though it's linked in the op and in my sig.

Is/was anyone else not aware of it?

Everyone that sticks to using the mobile app. Signature files aren’t visible.

[PaulGros]

Originally Posted by Assimilator1

Not had a chance to read later posts yet, but re hand measuring.
IIRC what they do is over stock on the bearings so that they have spare to be able to match and measure, then sell sets of hand measured shells within a very tight tolerance, negating any variances from the factory.
So they have no need to ask the factory for a specified wall thickness.

Re laser measuring, yes but they couldn't afford to bin or hold onto loads of shells could they? I'm sure you mentioned something like that if the tolerances were tightened right up.

Clevite will conduct in process automated measurements on certified equipment. ACL are 8um tolerance, MAHLE Motorsport are achieving 6um, OEM parts are 6um. Clevite manufactured parts are showing 12.7um tolerance from the published data. BE V1 & V2 shells show a different nominal clearance, yet the same wall thickness. If they are matching sets then both V1 & V2 should be the same clearance?

[Assimilator1]

Originally Posted by PaulGros

Clevite will conduct in process automated measurements on certified equipment. ACL are 8um tolerance, MAHLE Motorsport are achieving 6um, OEM parts are 6um. Clevite manufactured parts are showing 12.7um tolerance from the published data. BE V1 & V2 shells show a different nominal clearance, yet the same wall thickness. If they are matching sets then both V1 & V2 should be the same clearance?

I assume to achieve the different nom. clearance they are measuring the shells to a different figure?

[PaulGros]

Originally Posted by Assimilator1

I assume to achieve the different nom. clearance they are measuring the shells to a different figure?

I can't answer that question. I can see how they have arrived at the figure from the measurements, but cannot match that to the wall thickness data and the calculated figures. Maybe I'm going number blind

[Assimilator1]

Lol, no idea, but I'm assuming they're cherry picking the thinner shells to get bigger clearances in v2. (assuming like you say, that the supplied shell thicknesses are nominally the same as v1).

[jvictormp]

Originally Posted by Sneaky Pete

Its the same feed though?
If you massively increased rod bearing clearance, oil flow through the mains would be reduced or not?

In the main bearing, flow would increase, but pressure would decrease. That would reduce the distance between the crankshaft and the main bearing, potentially causing contact, although it would be more efficient at cooling due to high flow.

At the other side, if you reduce RB clearance, at the mains, pressure would increase and flow would decrease, potentially causing loss of cooling.

[kokuwow]

https://www.bimmerpost.com/forums/sh...php?p=30916918

Hi this is mu thread and we have some news about this case….When bring the car to the shop car didnt make any strange sound or knock.We waited to up the temp and nothing and nothing.Mecanic chek the oil filter and oil and didnt see metal.
Next day they down the oil pan and was clean no any metal in oil pan.We found in my car M Clevite bearings with apr bolts and maybe they are BE Bearings i m sure 100%.
On bearing shell is al clean no signs of the wear…
Now intersting part , mechanic told me that have some shadow on the crankshaft but nothing wrong and no have any signs of cracks….He start to measured clearence and call me and say that have some wear when make dimension with plasticgage.
He recomended to buy oem bearings and bolts and make measurement and see if really have wear .
I dont know what need to do….
This are picturs from shop.Someone know how much need to be clearence wit Be Bearing and ARP bolt tighten to 45ft?

This picturs are from cylinder 1 and 5

Thanks

[Assimilator1]

Assuming the plastigauge measurement has been done accurately (as much as it can), then that's about right for BE bearings, remember they are increased clearance bearings (which you can see for yourself if you check out their website).

Btw, really you should start your own thread for your case, this thread is for dead engines, it seems yours isn't .

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Btw folks, for reporting any future failed S65s, please post to my new thread which takes over from this one and my list here.
See this thread - https://www.m3post.com/forums/showthread.php?t=2093339