Another Rod Bearing Story

PDJ · Post by **PDJ** » Mon May 16, 2022 9:19 pm

Mr Tidy wrote: ↑Mon May 16, 2022 8:21 pm I'd love to see the difference in the viscosity of the oil at different temperatures

We have a machine in the lab at work for measuring just this

It will not be seeing any oil though as it is for food colour that goes in coke beer and whisky to name a few products we make colour for

Mr Tidy · Post by **Mr Tidy** » Mon May 16, 2022 9:23 pm

PDJ wrote: ↑Mon May 16, 2022 9:19 pm It will not be seeing any oil though as it is for food colour that goes in coke beer and whisk to name a few products we make colour for

That's a shame! What if the boss is out?

PDJ · Post by **PDJ** » Mon May 16, 2022 9:26 pm

Mr Tidy wrote: ↑Mon May 16, 2022 9:23 pm What if the boss is out?

Do you drink any of the above?

Mr Tidy · Post by **Mr Tidy** » Mon May 16, 2022 9:39 pm

PDJ wrote: ↑Mon May 16, 2022 9:26 pm Do you drink any of the above?

Not very often, but that's a fair point.

grannyknot · Post by **grannyknot** » Mon May 16, 2022 9:47 pm

R60BBA wrote: ↑Mon May 16, 2022 11:23 am
grannyknot wrote: ↑Fri May 13, 2022 9:10 pm Make sure you show those bearings to your to regular guy, he needs to stop saying that about s54's. Looks like you got them just in time.
Meh, he’s right. They are not as much an issue for S54’s than they are for other M engines such as the S65.

No he isn't and neither are you, bearings that can wear out in as little as 50k, whether an M engine or not are something you should be concerned about. If your not concerned, fine but bad advice is still bad advice.

flimper · Post by **flimper** » Tue May 17, 2022 9:00 am

Not sure if this has been mentioned before, but if you got the rod bearings done at say 60k, would you then have to get them done again at 120k or are the new bearings better quality now?

NLW73 · Post by **NLW73** » Tue May 17, 2022 9:33 am

do people go for OEM bearings or the King race style bearings? not sure if there is much difference and whether the king ones are harder wearing and can take higher revs?

you pays your way and take your chances....I know when I got mine at 98k and it had not been done it would not be long before they went. having the car opened up and the pics showed a fair bit of copper on show.

R60BBA · Post by **R60BBA** » Tue May 17, 2022 10:24 am

flimper wrote: ↑Tue May 17, 2022 9:00 am Not sure if this has been mentioned before, but if you got the rod bearings done at say 60k, would you then have to get them done again at 120k or are the new bearings better quality now?

Bearings can last 200,000+ miles as long as the car is looked after (ie regular oil changes and the car is warmed up properly).

It also depends on usage, for example race teams change them every season, whereas this would be completely unnecessary for someone who only uses their car on the road.

I will change mine every 75,000 - 100,000 miles for peace of mind as part of an Inspection 2 service and get the engine mounts changed as they will be past their best by then. However based on my usage that won’t be for another 10 years or so, and assuming I will still have the car by then…

PDJ · Post by **PDJ** » Tue May 17, 2022 2:51 pm

NLW73 wrote: ↑Tue May 17, 2022 9:33 am do people go for OEM bearings or the King race style bearings? not sure if there is much difference and whether the king ones are harder wearing and can take higher revs?

I went for King Race bearings

The OEM bearings have a top and bottom bearing the top one being made of a different mix of materials

The King Race bearings are the same top and bottom

It has been covered before but one of the reasons that the rod bearing are not as robust as some others are.

The piston is bigger and the rod bearing is narrower so more pressure is applied each time the piston is in the power stroke

This design change from the 3.0ltr engine size of piston and rod bearing width started to show its self while some S54 engines where under warranty so the fix was change the oil to 10/60W, Change the Top bearing material, make the bearings a service item as time passes it no longer becomes a dealer problem as out of warranty.

PDJ · Post by **PDJ** » Tue May 17, 2022 2:52 pm

Don't know of anyone on a second set other that race engines

GuidoK · Post by **GuidoK** » Tue May 17, 2022 3:07 pm

PDJ wrote: ↑Tue May 17, 2022 2:52 pm Don't know of anyone on a second set other that race engines

That's because most people here hardly do any miles (usually less than 10k miles/year), and/or usually flip the cars relatively fast. I mean people that hold on to the same car longer than 10 years are a minority on this (and most) forums.

XMetal · Post by **XMetal** » Tue May 17, 2022 3:30 pm

R60BBA wrote: ↑Tue May 17, 2022 10:24 am Bearings can last 200,000+ miles as long as the car is looked after (ie regular oil changes and the car is warmed up properly).

While this is true for a "normal" engine such as an M54, it's shouldn't be a blanket statement, especially for the S54. Mine has had it's oil changed regularly (every 3k-5k miles) and don't go past 4k rpm until car is properly warmed up. However, my oil analysis showed 15ppm average lead level since I started doing analysis at around 22k miles. Lead level dropped to less than 2ppm after bearings changed at about 55k miles. This steer me to believe that my bearings weren't properly installed (torqued) from day 1 at the factory. My car was built on March 2008, which I thought should be the latest and greatest iteration. I was obviously mistaken for making that assumption. I suspect many later S54 are the same, which is why I have seen worst bearing wears on S54 Z4M than those final E46 M3.

Even with the high average of 15ppm lead wear, the bearings made it to 55k and probably could have done another 10k miles, I'm fairly confident that the current set of bearings could make it to the next 100k easily with only 2ppm of lead wear...so my next change should be right around 150k.

XMetal · Post by **XMetal** » Tue May 17, 2022 3:32 pm

GuidoK wrote: ↑Tue May 17, 2022 3:07 pm
PDJ wrote: ↑Tue May 17, 2022 2:52 pm Don't know of anyone on a second set other that race engines
That's because most people here hardly do any miles (usually less than 10k miles/year), and/or usually flip the cars relatively fast. I mean people that hold on to the same car longer than 10 years are a minority on this (and most) forums.

This is true. Z3M/Z4M are usually weekender/garage queens. I know of a couple of E46M3 owners that are into their 3rd sets with 200k+ miles

TomK · Post by **TomK** » Tue May 17, 2022 3:42 pm

PDJ wrote: ↑Tue May 17, 2022 2:52 pm Don't know of anyone on a second set other that race engines

I am planning on getting mine done for the 2nd time very soon. It'll be interesting at the least to see what they look like, ~35k miles, I'd say at least 30% of those spent north of 5k rpm using the full 8k.
Always warmed up correctly. OE bearings with ARP bolts.
Of course the outcome could well depend on how they were installed so can hardly be conclusive I guess. I'll post them up when done.

GuidoK · Post by **GuidoK** » Tue May 17, 2022 4:16 pm

TomK wrote: ↑Tue May 17, 2022 3:42 pm Of course the outcome could well depend on how they were installed so can hardly be conclusive I guess. I'll post them up when done.

Bad installment will give a different wear pattern than the usual wear pattern.

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