Z4M Crank Rod Bearing Shells

Poll Poll Have yours been replaced

  • Not as far as I know.

    Votes: 51 56.0%
  • Yes, as a preventative measure.

    Votes: 35 38.5%
  • Yes, one or more failed.

    Votes: 7 7.7%

  • Total voters
    91
Ed Doe said:
I wouldn't be worried if it's had them before, in fact I'd say it's an indication its been looked after if someone's spend over a grand on a preventative maintenance item!

Precisely this ^
 
Yeah big bills are a good sign of intent / care. But does two sets of bearings that are worn mean that the car has not been warmed up correctly and / or thrashed?
 
DSGRNMCM said:
Yeah big bills are a good sign of intent / care. But does two sets of bearings that are worn mean that the car has not been warmed up correctly and / or thrashed?
I wouldn't worry too much, it's an s54, you can guarantee every single one on the roads has been thrashed at some point, that's the point of it :evil:
 
RedUn said:
DSGRNMCM said:
Yeah big bills are a good sign of intent / care. But does two sets of bearings that are worn mean that the car has not been warmed up correctly and / or thrashed?
I wouldn't worry too much, it's an s54, you can guarantee every single one on the roads has been thrashed at some point, that's the point of it :evil:

Great to be getting them done, but I would absolutely agree with this. My car’s 2k miles in to the new set of shells, I warm the car up carefully, and only do 2k miles a year, but those miles are enjoyable fast road miles... so I’ll probably have them done again if it ever gets to 100k miles under my ownership... worth every penny after another 15-20 years of use (hoping I still own it by then, I have every intention to). I mean, either it will be shells or I’ll be having an electric motor installed instead and the engine will become a centrepiece to our living room 😆😬
 
JoshsZ4M said:
RedUn said:
DSGRNMCM said:
Yeah big bills are a good sign of intent / care. But does two sets of bearings that are worn mean that the car has not been warmed up correctly and / or thrashed?
I wouldn't worry too much, it's an s54, you can guarantee every single one on the roads has been thrashed at some point, that's the point of it :evil:

Great to be getting them done, but I would absolutely agree with this. My car’s 2k miles in to the new set of shells, I warm the car up carefully, and only do 2k miles a year, but those miles are enjoyable fast road miles... so I’ll probably have them done again if it ever gets to 100k miles under my ownership... worth every penny after another 15-20 years of use (hoping I still own it by then, I have every intention to). I mean, either it will be shells or I’ll be having an electric motor installed instead and the engine will become a centrepiece to our living room 😆😬
:thumbsup: It's easy to get lost in the world of depreciation and maintenance costs etc.

S54 = :driving:
 
Simon 3.2M said:
I’m getting mine done soon - are King bearings and ARP bolts the gold to decision?

Got them in mine and never heard of any issues. Hack Engineering and many other specialists use this solution so good enough for me.
 
Simon 3.2M said:
I’m getting mine done soon - are King bearings and ARP bolts the gold to decision?

It is what the engine builders I talked to recommended and are fitted to my engine

Lymm engine components sell both and a gasket set for the work required.
 
Ross (Bowser) recommended ACL shells, so they are what I have.
 
So here are the old shells from my car. It is on 90k, these are AP Racing shells, so I'm assuming the second set.
upper and lower bearing.jpg
I'm no engineer, but they look "worn" to me, not sure what happens when they are "spun" I assume they break down and the debris causes damage to the engine?

Do you have to "run them in" and do you have to do an oil change after X miles as a new component has been fitted to the engine?
 
DSGRNMCM said:
So here are the old shells from my car. It is on 90k, these are AP Racing shells, so I'm assuming the second set.
upper and lower bearing.jpg
I'm no engineer, but they look "worn" to me, not sure what happens when they are "spun" I assume they break down and the debris causes damage to the engine?

Do you have to "run them in" and do you have to do an oil change after X miles as a new component has been fitted to the engine?

Damn they look pretty ruined to me, especially for a 2nd set at a mileage when most people are only replacing the originals! Did they inspect the crank for damage before they put it back together? You'd known if it had spun as you'd get a knocking sound which is the piston conrod banging on the crankshaft journal if a bearing had failed, though I would say you were pretty close to that point with a few of those bearings...(the lighting on the picture might be making it look worse but still).

99% sure AP Racing have nothing to do with engine bearings so not sure who told you they were made by them. King Racing I suspect is more likely if they have been replaced before.

Running in is a multiple answer depends who you ask kind of question. IMO, in theory no as there is nothing to 'bed' in as such. On the other hand, it doesn't hurt to take it easy for a few hundred miles / 1000 max just so if there's been any issues with the installation you'll be at lower revs and less likely to do damage. Plus any small containments that got in the oil / engine whilst apart and the assembly lube that was used can be flushed out with an oil change after that amount of mileage is done just for piece of mind.
 
After my rod bearing change and doing myself, I choose to run mine in a no real need to other than if you suffer infantile mortality failure it would be with lower load and revs and a paranoid sense of hearing.

I warmed the engine up each time I use the car let the oil pressure drop down to 50ish psi then start to drive the car watching the oil temp water comes up quickly oil slower. In the running in phase I used 3500 as a limit and light load on the engine after 1200 miles I changed the oil filter then at 2000 miles oil and filter. Oil will be changed this winter after around 6000 miles use using all of the engines range

This is what I did it makes sense to me
 
Can you take another picture of the bearing shells with a piece of white paper next to them for the colour corection.


They look in a bad way.
 
DSGRNMCM said:
So here are the old shells from my car. It is on 90k, these are AP Racing shells, so I'm assuming the second set.
upper and lower bearing.jpg
I'm no engineer, but they look "worn" to me, not sure what happens when they are "spun" I assume they break down and the debris causes damage to the engine?

Do you have to "run them in" and do you have to do an oil change after X miles as a new component has been fitted to the engine?

They look absolutely f***ed!! I’d say there were very close to spinning so you have changed just in time. What is of concern is that they are the second set! 😳

I’m getting mine done on Wednesday as I’ve no record of them being done.
 
DSGRNMCM said:
So here are the old shells from my car. It is on 90k, these are AP Racing shells, so I'm assuming the second set.
upper and lower bearing.jpg
I'm no engineer, but they look "worn" to me, not sure what happens when they are "spun" I assume they break down and the debris causes damage to the engine?

Do you have to "run them in" and do you have to do an oil change after X miles as a new component has been fitted to the engine?
I doubt those are AP Racing shells...what makes you think that?

AP Racing make big brake kits and clutches/pedal boxes - they don’t make con-rod bearing shells.

Those are some of the worst I’ve seen. You are lucky that they did not spin.

As per others what was the condition of your crankshaft? Was there any scoring?

You also mentioned they were a second set, how many miles have the shells covered?

In regards to your question of running-in, BMW recommend the engine should be run-in again after a rod bearing service but an oil change is not required.

Nevertheless it is good practice to drop the oil and can offer peace of mind at an insignificant cost...
 
Hi R60BBA,

The second set were not documented in the SH, so I can not tell the age / mileage. The garage who carried out the work informed me of the brand. I'm just happy it has been done, even though the local garages advised against it, and suggested oil analysis.
 
Results have come back from the oil samples. Both are taken at around 4000 miles. Car is at 50k miles.

If anything lead, copper and iron content has all been lower. The absolute values are not very high, so fingers crossed.

Previous Oil Sample:
Oil_1.JPG

Latest Oil Sample:
Oil_2.JPG
 
My car has 26k on the clock with very minimal mileage done last few years and owners.

Do you think I should get mine done due to age and not knowing how the owners prior to the last few used the car?

Also has anyone used Redish for this work as they are my local and look after my other cars.
Abid
 
Here are my bearing shells after 57,000 miles. Along very similar motivations to [ref]Mr Tidy[/ref], I decided to book my car in with RBM Hampshire (highly recommended btw). Turns out that at least one of the previous 9 owners of my car lacked mechanical sympathy :)
 

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