Rod Bearing Replacement

[Bnks334]

Maybe I didn't post it right. Only cylinder 6 was loose. When I pulled the bottom of the rod, that bearing was in place, but worn. The top of 6 was disintegrated. The crank and piston rod looked fine. No damage. The other rods were tight, but I went ahead and pulled those, too. Very minimal wear. Ordering parts now.

post up some pics for us

 

[yellaboyla]

Here u go. and yea, the crank is not shiny, so imma hit it, the cap, and piston with some 800 grit today

 

[Bnks334]

Here u go. and yea, the crank is not shiny, so imma hit it, the cap, and piston with some 800 grit today

That's going to take quite a bit of sanding. Probably going to have to start with 600 and end with 2000 and then some rubbing compound. Lube the paper up with some WD40 and stuff rags everywhere to mitigate the prorogation of sanding material. Hopefully that's mostly just bearing material that will sand off. Might have to sand the sided of the rod/cap too.

Good luck with it. That bearing is gone. Sometimes you can get away with a back-yard repair like this if you catch the knock early but this is not a very promising picture for a positive long-term repair.

 

[yellaboyla]

That's going to take quite a bit of sanding. Probably going to have to start with 600 and end with 2000 and then some rubbing compound. Lube the paper up with some WD40 and stuff rags everywhere to mitigate the prorogation of sanding material. Hopefully that's mostly just bearing material that will sand off. Might have to sand the sided of the rod/cap too.

Good luck with it. That bearing is gone. Sometimes you can get away with a back-yard repair like this if you catch the knock early but this is not a very promising picture for a positive long-term repair.

Yea, figured. But hopefully it hangs for 6 months. I can sell it, or build a block.....decisions

 

[yellaboyla]

Did you read the newtis.info guide? It explains how to get the code for which BMW bearings to use. Crank shaft is stamped with Y or R indicating standard red/blue or other shells. BMW mixed and matched shells to get every journal as close to target as possible. Target being somewhere around .0015" I believe.

No one really bothers using bmw bearings though. They are like $25 per shell. Expensive. You can get a standard set of builder bearings of the same quality for like $100. You're clearances just might have a bit more variance. Every e gine I've done usually lands between .0015" and .002" which is fine.

If you're just preventivly swapping bearings you should be able to just order up some King or ACL stadard (std) bearings and torque them in place with some plastiguage. Use your old rod bolts to do this. Check the clearance. Comes back between .0015" and .002" the. You're good. Clean off the plastiguage and re-torque using new rod bolts. If you have a journal that is way too loose or way too tight then you might have a bigger issue to look into. Most likely the bmold bearings would be showing some abnormal wear too.

So the only bearing that spun came back at .0015, others were at .002. I got the same bearings as the OP. (CR 222SV). Imma do a little 1000 grit polishing on the journal before i close it up. That journal has a small amount of uneven color after the 220/500/1000 grit cleaning. I feel no marks in journal with my nail. Plastiguage at 2 different spots, same reading.

 

[Asbjorn]

Just replaced my rod bearings at 150,000km with new oem type. Do you do low load run in and early 1000km oil change after this type of work?