who is still on original rod bearings?

[Doc Oc]

Originally Posted by R_lara

Doc oc what is side clearance damage?

Thanks

If you look at the pic I've attached (this is of an engine a friend of mine wanted to buy but turned out to have a spun bearing) you can see there are two rods per crank journal. Not only do we have to worry about the clearance between the bearing and journal of each rod but also the clearance between the two rods themselves as they are quite tight. In some engines possibly too tight, leading to excess heat and eventual failure. Not as common as the typical RB failure we see a lot but still a thing.

[Doc Oc]

Here is a picture of vac bearings that came out of my engine after 13k miles. You'll notice there isn't a hint of wear. And these bearings don't offer as much clearance as BE, which is why I say both of these options are as close as we can get to a permanent fix. My old bearings were chewed up badly so if the same thing was going to happen to the aftermarket bearings they should've shown some sign after a year and a half of hard use imo.

[pbonsalb]

And those are stock aluminum bearings with calico coating sold by VAC? In other words, not VAC's lead/copper clevite/calico bearings?

[Doc Oc]

Yup. Ordered the custom clevites but got coated oem. RG measured them for me and found some interesting info which I've quoted below:

"I measured your bearings for thickness, and clearance. VAC probably didn't send them to you as "uppers" and "lowers" -- but OEM's do have uppers/lowers. The difference is the thickness of the shell. In the two packages of 8 shells you sent me, there were a mixture of "thick and thin" bearing shells. The measurements showed there were 8 thick, and 8 thin shells. So if you pulled them as uppers and lowers and packaged them accordingly, I'd say the uppers and lowers were mixed in with each other. I re-sorted them as uppers and lowers."

"Yes, the VAC ARP rod bolts did add extra clearance to your shells. They ranged from 0.00005 inch to 0.00065 inch. But all of them did have some degree of bore distortion that added extra clearance. So let's assume that if my rods were all within spec, and they all had 0.0017 inch clearance, the extra 0.00065 would give you 0.0024 inch clearance -- which is exactly what BE Bearings are spec'd at without bore distortion."

So with stock bolts the clearance was .0017" and with arp bolts it was .0024". I guess the hardware is the key with these particular bearings.

[KawBoy]

BE bearings are also uppers and lowers; don't know if they are since day one though.

[geeitup]

Originally Posted by Mmn710

Here is my sample now.

Your lead is reduced, but at only 2500 miles, wouldn't it still be unacceptable if you would change the oil at BMW recommended interval? Seems like I'd still be budgeting for the bearing replacement.

I'm in a similar boat - I did a PPI and oil analysis on an M3 I want to buy and that car had similar levels to yours at 2000 miles.

[msan]

https://losangeles.craigslist.org/sf...062815565.html

279k miles

[ruderegime]

I purchase my E92 DCT M3 exactly a year ago this month and it had 89,xxx miles on it and now it has 99,xxx and I'm definitely paranoid about the bearings..... I can't find what thread I was reading about the bearings but it had like a list of what else that should be replaced when you do the bearings does anyone have that link? I'm also afraid of what the labor is going to cost me for the replacements

[Cbozz]

Originally Posted by msan

https://losangeles.craigslist.org/sf...062815565.html

279k miles

That's awesome!!!

[pbonsalb]

Originally Posted by ruderegime

I purchase my E92 DCT M3 exactly a year ago this month and it had 89,xxx miles on it and now it has 99,xxx and I'm definitely paranoid about the bearings..... I can't find what thread I was reading about the bearings but it had like a list of what else that should be replaced when you do the bearings does anyone have that link? I'm also afraid of what the labor is going to cost me for the replacements

It's about a $2500 job parts and labor.

[Magnetic Fusion]

Originally Posted by bond_007

2008 E90 with 143k, 77k of which are miles that I put on the car, mostly highway miles. Not sure if I need to start going car hypochondriac on the situation???

I guess I'll send used oil from the upcoming used oil to Blackstone and a sample of the fresh oil about 3k into use and see what they say?

I'm roughly at the same mileage, same year. My blackstone looked like crap but car is riding good. Slight vibration from the engine but this could be motor mounts or something like that. I got a quote for $2495 using original bearings and new ARP bolts. The shop is CIM Motorsports in NY. They actually race M3's and Porsche's and I asked about the aftermarket bearings and they said no, no need. Proper torque and your bearings will be fine. They said they have never had an engine fail using original bearings after they properly torqued them down. And they said the new bearings have no way of telling any wear due to the metals they are made of...tin or something like that. I'll be getting mine down in a few weeks. I have a youtube channel where I'll be tracking my progress. It's RDDC on YouTube...blue logo. Can't miss it.

[Magnetic Fusion]

Originally Posted by msan

https://losangeles.craigslist.org/sf...062815565.html

279k miles

So now I know there is a bottom price point for a high mileage M3...$15k. I was trying to figure out how much to sell mine for if I ever wanted to. I'm at half of his mileage

[pbonsalb]

Originally Posted by Magnetic Fusion

I got a quote for $2495 using original bearings and new ARP bolts. The shop is CIM Motorsports in NY. They actually race M3's and Porsche's and I asked about the aftermarket bearings and they said no, no need. Proper torque and your bearings will be fine. They said they have never had an engine fail using original bearings after they properly torqued them down. And they said the new bearings have no way of telling any wear due to the metals they are made of...tin or something like that.

This is the opinion of one shop, and one of the theories on why bearings are wearing excessively is improper torque. But there are aftermarket bearings made by the original company that are lead based that could be used rather than the aluminum factory bearings sold today. There are some other shops that recommend treated or coated or extra clearance bearings, that have never had an engine fail when these parts have been used. The guy who has done the most bearing changes and reinspected the most bearings after change is Malek at MRF and he uses VAC bearings that were originally stock coated and that are now lead Clevite with coating.

[Magnetic Fusion]

Originally Posted by pbonsalb

This is the opinion of one shop, and one of the theories on why bearings are wearing excessively is improper torque. But there are aftermarket bearings made by the original company that are lead based that could be used rather than the aluminum factory bearings sold today. There are some other shops that recommend treated or coated or extra clearance bearings, that have never had an engine fail when these parts have been used. The guy who has done the most bearing changes and reinspected the most bearings after change is Malek at MRF and he uses VAC bearings that were originally stock coated and that are now lead Clevite with coating.

Ok so I just got back from CIM Motorsports. I've got a video coming where he explains the rod bearings. He will be using WPC bearings since they are made by BMW and ARP bolts in case I feel like doing any mods later on. CIM races M3's so hard to not trust them. We will see. I'm sure everyone goes their own routes on what bearings to buy. But thanks for the info!! I spent awhile trying to find the perfect combo and a reputable shop. The mots i hear is WPC bearings and ARP bolts. So that's the combo I'm going with. Either way....I'm getting the crappy stock bearings out!

[MaximusB]

Originally Posted by Magnetic Fusion

Ok so I just got back from CIM Motorsports. I've got a video coming where he explains the rod bearings. He will be using WPC bearings since they are made by BMW and ARP bolts in case I feel like doing any mods later on. CIM races M3's so hard to not trust them. We will see. I'm sure everyone goes their own routes on what bearings to buy. But thanks for the info!! I spent awhile trying to find the perfect combo and a reputable shop. The mots i hear is WPC bearings and ARP bolts. So that's the combo I'm going with. Either way....I'm getting the crappy stock bearings out!

Race cars also get a complete engine tear down and rebuilt after each season, sometime after each race event. Unless something has gone wrong during reassembly they usually don't see any engine failure from hard driving.

[exVtekGuy]

Originally Posted by Doc Oc

Here is a picture of vac bearings that came out of my engine after 13k miles. You'll notice there isn't a hint of wear. And these bearings don't offer as much clearance as BE, which is why I say both of these options are as close as we can get to a permanent fix. My old bearings were chewed up badly so if the same thing was going to happen to the aftermarket bearings they should've shown some sign after a year and a half of hard use imo.

what weight oil was used with these? thanks

[Doc Oc]

M1 5w50. Been running it for almost a year on the new engine (OEM bearings) as well and have not had more than 1 ppm of lead in any of the 4 uoa's done during that time.

[oldmanstyle]

re: WPC rod bearings

How do these provide a benefit when there is no metal-on-metal contact with a rod bearing?

[Magnetic Fusion]

Originally Posted by oldmanstyle

re: WPC rod bearings

How do these provide a benefit when there is no metal-on-metal contact with a rod bearing?

I've always wondered how they call these things bearings in the first place haha! I worked for a bearing company and I never seen anything that looked like rod bearings.

[Doc Oc]

Originally Posted by oldmanstyle

re: WPC rod bearings

How do these provide a benefit when there is no metal-on-metal contact with a rod bearing?

If there were no metal on metal contact we wouldn't be having this discussion.

[Doc Oc]

Originally Posted by Magnetic Fusion

Ok so I just got back from CIM Motorsports. I've got a video coming where he explains the rod bearings. He will be using WPC bearings since they are made by BMW and ARP bolts in case I feel like doing any mods later on. CIM races M3's so hard to not trust them. We will see. I'm sure everyone goes their own routes on what bearings to buy. But thanks for the info!! I spent awhile trying to find the perfect combo and a reputable shop. The mots i hear is WPC bearings and ARP bolts. So that's the combo I'm going with. Either way....I'm getting the crappy stock bearings out!

I think your shop is right in that the hardware (and proper torque) is what makes the most difference, however by going wpc you are eliminating the option of oil analysis. For that reason alone I wouldn't use them, but if that's not a concern for you then I don't see any other drawbacks. A little extra clearance in the bearing wouldn't be a bad thing but if the arp hardware opens things up I suppose it's not necessary.

[oldmanstyle]

Originally Posted by Doc Oc

If there were no metal on metal contact we wouldn't be having this discussion.

Is the wear definitely metal on metal? That isn't the only wear mechanism.