Bmw OE parts “quality” main bearing content

[tlow98]

You wait 4 weeks for OE BMW mains to arrive. They show up and a couple of them look like garbage.

le sigh. Done venting. I’ll let you know what the parts department has to say about this. Of course it’s the special “white” size and will need another lengthy wait time. Yay.

It won’t let me post the zoomed in image, but there’s a sizeable divot with raised edges. Unusable. I suspect this wouldn’t pass inspection at the assembly plant.

[tlow98]

Some good news. After fitting all the other green and white bearings the clearances are spot on.

Now does anyone have an OE white top shell lying around? Should I call Lang?

thanks for listening to my sob story. Have a great Friday!

[thegenius46m]

Make them reorder. Annoying af to have to wait but I do it all the time. Inexcusable imho

[cobra]

Is it really gonna make a difference though? Realistically?

[tlow98]

Is it really gonna make a difference though? Realistically?

Yeah, I wonder the exact same thing. In reality, the bearing is super soft and crank super hard. I’m sure I could level it with an exacto knife. It’s also pretty far away from the critical portion of a fluid bearing.

I just don’t fully understand the fluid dynamics of these bearings. Does is affect the entire swipe of the bearing circumferential? Does it only affect the local spot? How much does that matter? All questions I can’t answer, so it seems one without big divot is better.

Would it last? My gut says yes. The problem is when you’re this far into it I just don’t want to leave anything to chance. There are some ~250 other details that need to be just right, and to do them all and leave this…

Do cars leave the factory like this? Maybe, but if the manager saw this work by an employee I imagine it’d be unacceptable.

It just irks me. Pricey af, all the way across the world and this turd shows up. C’mon.

[cobra]

I completely agree. I'd want a new one too. But I also would be frustrated knowing it probably doesn't matter and it's more about the peace of mind and principle of knowing you paid good money to get a perfect new part and not some thing that's been bouncing around getting dinged up.

[stash1]

It looks like it was either dropped, or something dropped on it to cause that ding. Realistically, I don't think that it would cause any problems as long as they're no raised areas around the ding; however, if it were me, and I went to all of the time/trouble/expense to build a motor I'd replace it. If this was going in a pedestrian small block Chevy that never saw over 6,000rpms, I think I'd let it eat...but this is going in a semi-race engine that already has tighter than normal clearances and spins to 8,000rpms. I think that it would always be in the back of my mind, and that it would prolly drive me crazy just thinking about it-lol.

[tlow98]

It looks like it was either dropped, or something dropped on it to cause that ding. Realistically, I don't think that it would cause any problems as long as they're no raised areas around the ding; however, if it were me, and I went to all of the time/trouble/expense to build a motor I'd replace it. If this was going in a pedestrian small block Chevy that never saw over 6,000rpms, I think I'd let it eat...but this is going in a semi-race engine that already has tighter than normal clearances and spins to 8,000rpms. I think that it would always be in the back of my mind, and that it would prolly drive me crazy just thinking about it-lol.

bingo. And yes, it has raised edges around the ding. Pretty significant ones where the metal was displaced.

it’s mostly just annoying bc I went this route as it would be the most trouble-free route. Oh well!

[eacmen]

Be patient. Order the replacement. Or order 3 replacements and keep the best one and return the others.

When I order rod bearings I always order enough for 7 cylinders and pick the best ones and return the duds.


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[Cronenberged]

Send em to microblue for treatment.

[tlow98]

Be patient. Order the replacement. Or order 3 replacements and keep the best one and return the others.

When I order rod bearings I always order enough for 7 cylinders and pick the best ones and return the duds.


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smart. Thanks!

[bigjae46]

If there’s a low spot…I’d imagine that you would NOT want to use it. I’m guessing that would create a hot spot or an edge that could catch and score the crank.

[digger]

burnish the area to remove the raised part and drive it like you stole it

[tlow98]

burnish the area to remove the raised part and drive it like you stole it

I was able to get some from a local dealer. So yeah, I think ill
just replace it. Install, measure, and take it from there

[tlow98]

Ok, so round two.

For the life of me couldn’t figure out why I couldn’t get the thrust bearing in spec. Turns out, it’s messed up, too.

pretty large machining error that left a sizable lip.

another day, another return to zee Germans. PSA to check your bearings very carefully!