Official S65 Rod Bearing Condition Example Thread

[Scrippy]

Originally Posted by Dreamer99

Aren’t the WCP bearing a tight clearance bearing with the treatment on the surface? Maybe the issue with our bearings is mostly bolt related?

Yes regarding surface treatment, unsure on clearances. I though WPC allotted more gap?

[pbonsalb]

Originally Posted by Scrippy

2nd set I've pulled for replacement. These are WPC bearings with ARP bolts used and they've gone 98,000 & 4 summer track days in SoCal.

2-2nd set replaced with 98,000 of use. (WPC/ARP bolts).
*the enclosed picture and they look amazing!

Great to see a high mileage set of replacement bearings, of any type! Few of the small percentage of the owners who have changed once have driven enough to change again. Also good to see a positive report on WPC (jcolley has a negative report so it’s now a tie). Many positive reports on both versions of VAC bearings from Malek. Still waiting on reports from the newcomer, BE, but I think they will be positive and they are probably the ones I will use to replace my now 4 year old 30k mile WPC bearings when I change again.

[deansbimmer]

Originally Posted by 330ciprem

It's a micro level treatment that fills in the crevices on the surface. The clearance remains the same but 2 things change

Friction reduces.
Bearing strength increases.

Partially correct...

WPC is a micro-peening surface treatment. It does not "fill in" anything. it does help blend and peen surfaces at a microscopic level, and therefore it does have a strengthening affect in the same way that shot peening helps strengthen connecting rods (for example). This relates to surface tension as the treatment only affects the bearing face. The shell strength remains the same.

Also, practical clearance does in fact slightly increase with WPC treatment as the blasting agent removes a very small amount of bearing surface. For a long time before VAC or BE released their own Clevite bearings, WPC treated OEM bearings were the only option and was preferred over standard OEM bearings for this reason. I would hazard a guess that to date there are more OEM/WPC treated bearings installed into these cars than BE/VAC combined.

References:
http://www.wpctreatment.com/about.htm
http://wiki.rcollins.org/core/index....5_Rod_Bearings

[Silverstoneorspacegray]

Interesting, makes me feel better about my WPC bearings at least

[Pig Farmer]

Has anyone sent their BE bearings to WPC for the micropeening treatment before installing?

[G80indy]

What are those scratches from?
Disassembly?

[Scharbag]

Originally Posted by Pig Farmer

Has anyone sent their BE bearings to WPC for the micropeening treatment before installing?

BE bearings are designed to have adequate clearance. Also, BE have a "tri-armor" coating on them. Not sure how WPC treatment would work out with the coating.

Cheers,

[rdoctor]

Just got my RB's changed this week. I'm glad I did! Replaced with BE Bearings and BE ARP bolts.

2009 e92M3, 52,321 miles 7,500 mile oil change intervals with 10w60, proper warm up routine during my ownership (I'm not the first owner).

[Transfer]

I both love and hate all the amazing bearing discussion that goes on in this forum. Kudos to all who have a knowledgeable hand in it! I'll add some questions here and hope it's the right place to do so. I didn't want to start yet another thread.

Today I have been burning my day being enthralled with what to do about these marvelous S65s with their potentially fatal flaw. The rabbit hole of discussion can really go and go. I started with this post which got me reading all kinds of things about oil additives Ceratec and MoS2. That lead me to this thread which has a fantastic discussion of VAC coated extra clearance vs OEM coated bearings and of course ARP bolts. The final point of contention in that thread is pristine OEM clevite bearings, VAC coated, with ARP bolts at 13k miles while this post shows these same bearings installed with OEM bolts, highly worn after just 1500 miles!

So, do we know if ARP bolts provide enough of bore distortion to adequately increase clearance on OEM bearings? I suppose if you're changing bolts you're going to be changing bearings as well so probably a moot point.

Are the OEM bolts and possibly their installation the problem with the worn 1500 mile VAC coated OEM bearings in the link above?

If installing BE extra clearance bearings, I'm assuming the the ARP bolts are still recommended (certainly they seem easier to install correctly) but do they then add even more clearance to the already loosened up BE bearings?

[deansbimmer]

Originally Posted by Transfer

So, do we know if ARP bolts provide enough of bore distortion to adequately increase clearance on OEM bearings? I suppose if you're changing bolts you're going to be changing bearings as well so probably a moot point.

Are the OEM bolts and possibly their installation the problem with the worn 1500 mile VAC coated OEM bearings in the link above?

If installing BE extra clearance bearings, I'm assuming the the ARP bolts are still recommended (certainly they seem easier to install correctly) but do they then add even more clearance to the already loosened up BE bearings?

--Rod bolts do not increase bearing clearance- that is not their function nor is that even remotely desirable. The goal with rod bolts is to provide adequate clamping force without introducing bore distortion (out of roundness). That's why we see different companies doing their own bolts- they all want to claim their bolts yield the roundest bore. OEM bolts, when properly installed maintain a very good round bore in the connecting rod. There are several versions of bolts made by ARP sold by ARP and other private labels. The BE versions sold along side their increased clearance bearings result in a nearly perfect bore as well. The abnormally tight clearances that OEM bearings give only exaggerate the wear from a slightly distorted bore. That's why we should all be going to bearings that increase clearances closer to the industry standard.

--That could be speculated but not really proven. Any time you complicate an installation procedure, you're going to introduce a chance for error. Since ARP bolts are a one step torque procedure instead of 3, the ARP's may yield a more consistent/accurate clamp than the average-joe installed OEM bolt.

--BE's ARP bolts they sell with their bearings have been developed together to yield consistent round bores and improved journal clearances. If you were building an engine out of the car you'd be checking all clearances with special tools and adjusting as needed if anything doesn't add up. But since 99% of us are going with a plug-and-play replacement, when combined with their bearings you may have a better chance of long term success using a combo that was designed and tested to work properly together.

[Scharbag]

Originally Posted by deansbimmer

--That could be speculated but not really proven. Any time you complicate an installation procedure, you're going to introduce a chance for error. Since ARP bolts are a one step torque procedure instead of 3, the ARP's may yield a more consistent/accurate clamp than the average-joe installed OEM bolt.

It is really more like an 11 step torque procedure per bolt with OEM...

[aswy6]

I have a quick question here. What is by some miracle, rod bearings will come out with minimal wear, would you still put increased clearance bearings in there?

[pbonsalb]

That is up to you. I think it would be a good sign your engine tolerances are reasonable and your driving reasonable. I personally would still install increased clearance bearings. It’s not excessive clearance. Rather they just move the clearance from the narrow end of the range to the industry standard, not to the wide end of the range.

[doogee]

Originally Posted by aswy6

I have a quick question here. What is by some miracle, rod bearings will come out with minimal wear, would you still put increased clearance bearings in there?

Yes. They shouldn't be wearing at all for the most part.

[qbnlykwhoa]

Here are mine done over at ACM.
2011 with 51,xxx. I am the second owner since 36,xxx.

[cplagz]

Unfortunately I wasn't present when the bearings were pulled so not sure what cyl order is, but here are mine at 59,873kms. I have only owned the car since 55,000kms.

[330ciprem]

Originally Posted by cplagz

Unfortunately I wasn't present when the bearings were pulled so not sure what cyl order is, but here are mine at 59,873kms. I have only owned the car since 55,000kms.

Oh my!

[ItsGary]

I forgot what garage it was or vendor, they suggested that when doing the bearings to switch over to 0w50 cause it holds temps better?

[bosse92m3]

Originally Posted by cplagz

Unfortunately I wasn't present when the bearings were pulled so not sure what cyl order is, but here are mine at 59,873kms. I have only owned the car since 55,000kms.

Wow
What kind of bearings and bolts did you go with ?

[GORDON.M3]

Originally Posted by cplagz

Unfortunately I wasn't present when the bearings were pulled so not sure what cyl order is, but here are mine at 59,873kms. I have only owned the car since 55,000kms.

Looks about right, my car with the same kinda mileage had the same kinda wear. Also a 09.

[rdoctor]

Originally Posted by gordon@

Looks about right, my car with the same kinda mileage had the same kinda wear. Also a 09.

Mine too. Also an 09. See post #624 above. My mechanic thought I was getting a little caught up in the RB hype when I asked him to do the job but when the first bearing came out he was shocked at the wear with only 51K miles.

[tdott]

2011 with 55k I did a few weekends ago: