CSL crankshaft bearing shell

[Monkey]

I've honestly never had a reason to replace rings on these. If a cylinder leakage test is carried out and the readings are acceptable there would be nothing to gain from replacing them.

If you want to replace them anyway you would need to measure the bore to see if there is any wear, and whether it is in tolerance or not. If it is you could just go ahead and fit the new rings.

It's a massive job to be honest, and not one that most would want to undertake voluntarily!

Yes if the head is off you could lap the valves in, however I would go back to the cylinder leakage test and if the values are ok again there would be nothing to gain by doing this. These dont suffer from coking up, so generally it's not necessary to clean the ports. When replacing the head gasket the head is not stripped (assuming inspection shows no issues).

With regards to the original post topic (big end shells), I've only personally seen 2 cars fail so it is a small percentage.

[Chad]

Rod bearing shells

Regarding rod Shells, when replacing shells, does BMW have anyway of polishing of debris on crank faces left by worn shells, while in still In motor, possibly a good question for monkey,any info on this mate

[Monkey]

Hi Chad,

We do not have such a tool I'm afraid. If there's any sort of pick up on the crank then it's usually pretty big issue. Depends what you mean by debris!

When replacing bearing shells it's normal procedure to use plasti gauge to measure the clearance. Depending on the results of that will tell you which size crank shells are needed.

Regarding rod Shells, when replacing shells, does BMW have anyway of polishing of debris on crank faces left by worn shells, while in still In motor, possibly a good question for monkey,any info on this mate

[Chad]

Hi Chad,

We do not have such a tool I'm afraid. If there's any sort of pick up on the crank then it's usually pretty big issue. Depends what you mean by debris!

When replacing bearing shells it's normal procedure to use plasti gauge to measure the clearance. Depending on the results of that will tell you which size crank shells are needed.

Ok that sorts that, Not that mine needs doing, just that I have a spare crank that needs a bit of TLC, my local engine specialist recon they can polish spare crank , not a regrind, to be as good as new, it does have some signs of pick up but mics up ok, cheers monkey any thoughts on that are welcome. Chad

[GregorFuk]

Can I ask. When people are replacing shells, cams, followers etc how are they running their engine in?

I have always assumed that the first 1000mile service is such big deal for these engines because they come with a different 'running in oil'. One would assume that if you are changing the aforementioned bits then you need to go through the process again. If that is the case that what oil should be used?

[Bounce]

Was always told the running in oil was a myth and they used TWS

[select]

Can I ask. When people are replacing shells, cams, followers etc how are they running their engine in?

When i had mine done, i specifically asked if i need to run it in. They said no.
Running-in Procedure is not because of the bearing shells but more about the cylinder wall and the pistons.

EDIT: I should add that i only had my bearings replaced, i think if cams have been replaced you should defininately give the engine some time to run it in.
In that case i would just stick to the regular BMW Running in Routine.

Was always told the running in oil was a myth and they used TWS

As far as i know they use some light oil for running in. Something like a 5w-30? Not sure though.

[Chad]

Hi Chad,

We do not have such a tool I'm afraid. If there's any sort of pick up on the crank then it's usually pretty big issue. Depends what you mean by debris!

When replacing bearing shells it's normal procedure to use plasti gauge to measure the clearance. Depending on the results of that will tell you which size crank shells are needed.

Thought I'd add some pictures of striped down spare csl motor as there doesn't seem much about on forum... Back to crank. What the views on pick up on this crank, would you get this polished up or just bang in some new shells , I would imagine this is typical of most cranks. Before reshelling ????

[Chad]

A few vanos Head and cam shaft pics for reference

[Monkey]

Thought I'd add some pictures of striped down spare csl motor as there doesn't seem much about on forum... Back to crank. What the views on pick up on this crank, would you get this polished up or just bang in some new shells , I would imagine this is typical of most cranks. Before reshelling ????

Hi Chad,

Can you feel that pick up with a sharp pick? or your finger nail? If so it would need some attention. You'd also have to measure it with the plastiguage to see if its excessively worn, and to determine which shells you put in when you put it back together.

[Chad]

Hi Chad,

Can you feel that pick up with a sharp pick? or your finger nail? If so it would need some attention. You'd also have to measure it with the plastiguage to see if its excessively worn, and to determine which shells you put in when you put it back together.

Hi James. Yes you can definitely feel some light pickup with finger nail, but doesn't appear to affect measurements, As in photo, interesting thing pickup arrears to be mainly on rod bearing 3 and 4. Also mains bearings either side and centre, appear to take the most abuse. And sprocket side no 1 main bearings is slightly the most warn . Out of interest, a a local engine shop recon this pickup on crank bearings faces should polish up perfectly, out of interest including some photographs , measurements taken and close up photos ..what's your take on measurements, regarding shells! I'm thinking refitting std shells... :thumbs:

[Chad]

Sorry more pictures. This motor and crank spun a shell at about 70 or 80k miles. New shell fitted ran on for another 20k ..but can't remember which one spun .

[Chad]

Imagine of shells. From rod 3 and 4. Definitely more wear to these shells, which coincides with pickup on bearing faces 3 and four, ... Would be interested to hear if this is typical of csl or std m3. Other rod shell don't look to bad, and this coincides with other crank bearing faces being fairly pickup free, ... also noticed most of wear appear to be or the rod shell , bottom shell definitely have less wear in general, ... pictures shows rod 3+4 first. I've definitely seen shell bearings looking a lot worse, so can only imagine once you can see the copper colour on shells there will be a fair amount of pickup on crank faces, pity BMW don't do some kind of temporary shell that can be fitted to polish up crank faces and be then removed......Hopefully of interest to someone

[niall1]

I recently hit 70k miles in mine and as it's no longer my daily I thought it better to have some preventative maintenance with a bottom end rebuild at this service, as I had read about issues with these engines around this mileage. The car has always been regularly serviced and has only done a handful of track days in it's 70,000 miles (almost 50k of those in my care).

The bearings were almost down to the copper! Just a heads up for those still using their cars as they were meant..

Niall

[Chad]

I recently hit 70k miles in mine and as it's no longer my daily I thought it better to have some preventative maintenance with a bottom end rebuild at this service, as I had read about issues with these engines around this mileage. The car has always been regularly serviced and has only done a handful of track days in it's 70,000 miles (almost 50k of those in my care).

The bearings were almost down to the copper! Just a heads up for those still using their cars as they were meant..

Niall

Pictures of the shells in previous post, are of the second set of shells fitted, they only did 30k maximum. These shells are from the first set including spun shells at about 70k :whistle: