New Rod Bearings at 92k miles (but old ones look great!)

[FogCityM3]

Yeah, I asked the same question. Answer was 1) OEM bolts have never failed or been the source of any witnessed failure in street or race engines; 2) competent techs have no issues with the tightening process when using the right tools.

Originally Posted by MPower7

Interesting why they went with the Original bolts over ARP? Don't they have an 11 step tightening process?

[tdott]

Originally Posted by FogCityM3

Your opinion stands in stark contrast to Dinan's and to the pictures themselves (the top layer is BARELY worn).

Even the "normal" ones in the pdf are showing wear!!!

Not sure what the motive/point is here with this preposterous argument!

Dinan's customer service money at the front probably just wants to make you feel good, they aren't going to go in depth about bearings which a customer is not likely to understand.
While the picture in the pdf is not great, it is showing little wear but yours show the top silver layer worn.

My point is that while not terrible, your own bearings do still show more wear than is normal.
I'm done trying to educate you. Believe what you want.

[Helmsman]

Thanks for posting OP. Like tdott I noticed the shells look dark all over, rather than light grey (assuming 703/702). Curious why this is, or is it simply the way they came out in the picture?

[FogCityM3]

YEah, it's the picture..will post a better one with a better camera. Thx for the suggestion.

Originally Posted by Helmsman

Thanks for posting OP. Like tdott I noticed the shells look dark all over, rather than light grey (assuming 703/702). Curious why this is, or is it simply the way they came out in the picture?

[FogCityM3]

Good. Many people in the bay area have had a long-standing relationship (including myself) with the people at Carbahn/Dinan and they're the same guys who've been there for a long time; those who have dealt with them know they are not only honest, but brutally honest.

So according to your "feel good argument", I just parted with $3k of my money and they made "feel good" by saying my bearings were in great shape? Wouldn't it be the opposite!??! (and I spoke to the person who did the job, I've known for years. This was one of the reasons why I went there).

Again, totally preposterous!

Originally Posted by tdott

Dinan's customer service money at the front probably just wants to make you feel good, they aren't going to go in depth about bearings which a customer is not likely to understand.
While the picture in the pdf is not great, it is showing little wear but yours show the top silver layer worn.

My point is that while not terrible, your own bearings do still show more wear than is normal.
I'm done trying to educate you. Believe what you want.

[RedScytheM3]

Originally Posted by FogCityM3

Good. Many people in the bay area have had a long-standing relationship (including myself) with the people at Carbahn/Dinan and they're the same guys who've been there for a long time; those who have dealt with them know they are not only honest, but brutally honest.

So according to your "feel good argument", I just parted with $3k of my money and they made "feel good" by saying my bearings were in great shape? Wouldn't it be the opposite!??!

Again, totally preposterous!

You're missing the point. You sound as if you're taking it personally.

Your old bearings look good when compared to the population of M3 bearings that have been pulled. However, your old bearings exhibit more wear than one would normally expect on rod bearings in general. So amongst us you came out ahead, but amongst all rod bearings you probably didn't.

[FogCityM3]

If you look at the history of my posts on this subject (way way prior to my bearings being pulled), you may come to a different conclusion as to whether I'm really missing the point

Originally Posted by RedScytheM3

You're missing the point. You sound as if you're taking it personally.

Your old bearings look good when compared to the population of M3 bearings that have been pulled. However, your old bearings exhibit more wear than one would normally expect on rod bearings in general. So amongst us you came out ahead, but amongst all rod bearings you probably didn't.

[radiognome]

Keep in mind that since your car is 2011.5 you were running 702/703 bearings, comparing with 088/089 which were used in 2007-mid 2010 cars.

From this wiki:

EU mandates against lead/copper bearings began in 2011. However, S65 engines have been seen with mid-2010 production dates having these newer 702/703 bearings. These bearings remained in production until the end of S65 production in 2013.

The new 702/703 bearings are made from tin/aluminum composition. BMW increased the clearance slightly over the 088/089 bearings and increased the eccentricity as well. But this improvement in clearance and eccentricity came at a price. The 702/703 bearings are substantially harder than the 088/089 bearings they replaced. As a consequence, when a bearing is spun, it tends to cause more damage to the crankshaft in the process.

[nyc_dude]

As stated above, your 2011 M3 has harder tin/aluminum bearings, so the RB service was not required. You should have changed the motor mounts ($100) for a smoother idle through the car. BE here in LA (Auto Talent) sells the bearings with ARP bolts as a set. The BMW OEM bolts take forever to torque and stretch, so you can't reuse them. ARP bolts (racing standard for decades) don't have this issue.

Price for the service was $2000, so you were overcharged by 50%.
I bet you paid a fortune for the BMW OEM bolts.

I did my RBs at 180k miles (twice your mileage) at BE/Auto Talent. Wear was at the seams with exposed copper. Blackstone said my copper/lead was great, using junk BMW 10w60 oil at 15k mile intervals.

Piece of mind is a good thing, but other maintenance bills will pile up after 80k miles.
M3 e9x RB service is cheaper than a brake job.


Cheers,

[Scharbag]

Originally Posted by nyc_dude

As stated above, your 2011 M3 has harder tin/aluminum bearings, so the RB service was not required...

Could you elaborate on the above statement?

[FogCityM3]

Motor mounts were done on my car at 80k miles (did it preemptively when transmission was out). One of them was in pretty bad shape.

Obviously RB job in LA will be cheaper than in SF (like everything else relative to the highest cost metro area in the US). The reputable shops all charge around the same amount here. Even if there were price differentials, I would only trust 2 places in the Bay Area to do the work.

As far as the bolts, as mentioned Carbahn/Dinan have been satisfied with performance of OEM ones, and not sure why re-usable bolts are necessary unless techs are less skilled in RB installs given the anticipated engine life. Dinan has been very satisfied with the performance of the stock ones (none have broken and none were torqued improperly in the hundreds they've done for race and street cars), and not going to argue with the very same people who have the most extensive engine building experience in the US for BMWs. You could specify any bearing/bolt combination and they would have installed it....BUT not provided the 2 yr warranty.

Bearing issues have been seen on both the tin/aluminum as well as the lead/copper. It's true that I didn't need a RB job and that they would have lasted to about 130k-150k miles (the service life of an M engine). While some may state that it's excessive wear for 90k or 130k miles, but kind of irrelevant point if engine doesn't last beyond that no matter what bearings are in there.

Originally Posted by nyc_dude

As stated above, your 2011 M3 has harder tin/aluminum bearings, so the RB service was not required. You should have changed the motor mounts ($100) for a smoother idle through the car. BE here in LA (Auto Talent) sells the bearings with ARP bolts as a set. The BMW OEM bolts take forever to torque and stretch, so you can't reuse them. ARP bolts (racing standard for decades) don't have this issue.

Price for the service was $2000, so you were overcharged by 50%.
I bet you paid a fortune for the BMW OEM bolts.

I did my RBs at 180k miles (twice your mileage) at BE/Auto Talent. Wear was at the seams with exposed copper. Blackstone said my copper/lead was great, using junk BMW 10w60 oil at 15k mile intervals.

Piece of mind is a good thing, but other maintenance bills will pile up after 80k miles.
M3 e9x RB service is cheaper than a brake job.


Cheers,

[Scharbag]

Originally Posted by FogCityM3

Motor mounts were done on my car at 80k miles (did it preemptively when transmission was out). One of them was in pretty bad shape.

Obviously RB job in LA will be cheaper than in SF (like everything else). The reputable shops all charge around the same amount here.

As far as the bolts, as mentioned Carbahn/Dinan have been satisfied with performance of OEM ones, and not sure why re-usable bolts are necessary unless techs are less skilled in RB installs given the anticipated engine life.

Bearing issues have been seen on both the tin/aluminum as well as the lead/copper. It's true that I didn't need a RB job and that they would have lasted to about 130k-150k miles (the service life of an M engine). While some may state that it's excessive wear for 90k or 130k miles, but kind of irrelevant point if engine doesn't last beyond that no matter what bearings are in there.

I used ARP bolts so that I did not risk screwing up the 88 torque steps factory bolts require.

[kawasaki00]

Originally Posted by FogCityM3

Motor mounts were done on my car at 80k miles (did it preemptively when transmission was out). One of them was in pretty bad shape.

Obviously RB job in LA will be cheaper than in SF (like everything else relative to the highest cost metro area in the US). The reputable shops all charge around the same amount here. Even if there were price differentials, I would only trust 2 places in the Bay Area to do the work.

As far as the bolts, as mentioned Carbahn/Dinan have been satisfied with performance of OEM ones, and not sure why re-usable bolts are necessary unless techs are less skilled in RB installs given the anticipated engine life. Dinan has been very satisfied with the performance of the stock ones (none have broken and none were torqued improperly in the hundreds they've done for race and street cars), and not going to argue with the very same people who have the most extensive engine building experience in the US for BMWs. You could specify any bearing/bolt combination and they would have installed it....BUT not provided the 2 yr warranty.

Bearing issues have been seen on both the tin/aluminum as well as the lead/copper. It's true that I didn't need a RB job and that they would have lasted to about 130k-150k miles (the service life of an M engine). While some may state that it's excessive wear for 90k or 130k miles, but kind of irrelevant point if engine doesn't last beyond that no matter what bearings are in there.

Most view it as since you have to replace the rod bolts might as well get better ones (arp). The cost difference is moot after it is all done.

[Scharbag]

Originally Posted by Merlin_83

Greetings,

Finally a report of bearings not being totally trashed.

Also where is the data coming from when people state that 50% of the S65's have less than optimal clearance?

The S65 and S85 are not hand built, there built the same as other non M engines are made. Mostly by automation, robotic and some small amount of human interaction. This is what I've been told by several BMW employees (not dealership).

Thanks,
Merlin

This can be shown with some statistics. It has been some time since I have had to solve this sort of thing, but it can be done.

BMW's base design calls for 0.00145" clearance when using 088/089 bearings or 0.00170" clearance when using 702/703 bearings. If you follow Clevite's or ACL's recommendations, as well as time tested engine building best practices, the clearance for the S65 should be ~0.00240" as per BE Bearings nominal design.

There will ALWAYS be manufacturing variance. This means that some part combinations will have lower than nominal clearance values while some will have higher than nominal clearance values. Given that nominal BMW clearance is already significantly less than recommended for hydrodynamic bearings in high RPM reciprocating engines, the result is that most S65 engines have a high probability of having tighter than recommended rod bearing clearances.

The tables below, borrowed from the S65 Wiki, show that with 088/089 bearings the clearance can range from WAY TOO TIGHT to still too tight... The 702/703 are a little wee bit better but still below the recommended amount.

Also shown are the BE designed bearing measurements. Nominal is exactly what you want. Due to stacking factors, there is still the chance that the bearings will be tight-ish compared to Clevite's recommendations but close enough. Thankfully, the tightest BE bearings will still be better than the nominal clearance for both the 088/089 and 702/703 bearings.

Cheers,