Official S65 Rod Bearing Condition Example Thread

[kawasaki00]

Originally Posted by Sneaky Pete

Finally on a broader note....given that new BE extra clearance bearings already cause an oil pressure drop, I'm surprised that buyers aren't more concerned that as the coating wears off this will only would further reduce the oil pressure compromising the oil flow through the Main bearings.
It will certainly be interesting to see how instances of main bearing failures increase in engines that have had extra clearance RB bearings fitted.

On that size main shaft .0003 to .0004 across all journals is about .5gpm flow. Considering the oil must flow through the mains before it gets to the rods a rod clearance of .003 still provides adequate oil pressure across the rods according to the bmw service manual. Even if one were to lose 5psi from bearing wear it is still above the factory minimum because of the pump capability.
If you are going to make a case for the BE bearings lowering OP down below the factory minimum then we can talk but that is not the case so your point is not even worth considering.

[doogee]

Originally Posted by kawasaki00

Any coating that is meant to "come off" is a bad coating and a waste of money.

Well then you can put both Calico and Clevite in that category.

[kawasaki00]

Originally Posted by doogee

Well then you can put both Calico and Clevite in that category.

Yep and thats why calico coatings suck, the clevite coatings that are a dry graphite are meant for installation and start up. The tri-metal are not meant to come off and dont if they are set up properly.
I will rephrase that, they dont suck they are just not as good as they were years ago, therefore no race teams use them on bearings any longer.

[doogee]

Originally Posted by kawasaki00

Yep and thats why calico coatings suck, the clevite coatings that are a dry graphite are meant for installation and start up. The tri-metal are not meant to come off and dont if they are set up properly.

Clevite Tri-Armor coatings wear off as well. Not even Clevite makes your claim. Clevite warranties it for 1 year.

I mean even if you look at an example above you'll see the coating failing at just 5000 miles.

You can't argue with facts or choose to believe what you want. I guess you could say all coatings suck .


You also seem to be confusing the actual bearing materials which are referred to as "Tri-Metal" with the coatings which are called "Tri-Armor". So you're talking about a made up coating that doesn't exist.

[Sneaky Pete]

Originally Posted by doogee

I personally prefer VACs approach by using the coating as it is intended. It's a sacrificial layer that is going to wear off. This only applies to the newer custom bearings.

This from a little over a year ago, should reassure a little:
http://www.m3post.com/forums/showpos...&postcount=419

[doogee]

Originally Posted by Sneaky Pete

This from a little over a year ago, should reassure a little:
http://www.m3post.com/forums/showpos...&postcount=419

Yeah I'd say it's pretty well known that VAC bearings are a solution.

I have VAC clevite installed. But if I had BE Bearings, I'd feel just as confident in them.

I still recommend both.

[Bartledoo]

Originally Posted by Sneaky Pete

That's a little disappointing...I didn't have you down as being a bit of a dick...ah well at least you have company.
Anyway what is it *you* think that I'm supposed to be "agreeing" [with the people he's been arguing against all along]?

Also, maybe you know why BE go so much out of their way to knock a competitor's product?...a lack of confidence in their own product or just a lack of integrity?

Sorry man, I just suspect you're messing with our heads a bit! Argument - the variation is most likely causing catastrophic failures. If you have a given tolerance range then you need to choose a nominal value which doesn't put either extreme at risk.

[Sneaky Pete]

Originally Posted by kawasaki00

On that size main shaft .0003 to .0004 across all journals is about .5gpm flow. Considering the oil must flow through the mains before it gets to the rods a rod clearance of .003 still provides adequate oil pressure across the rods according to the bmw service manual. Even if one were to lose 5psi from bearing wear it is still above the factory minimum because of the pump capability.
If you are going to make a case for the BE bearings lowering OP down below the factory minimum then we can talk but that is not the case so your point is not even worth considering.

Given that:
The use of BE extra clearance bearings not only uses up all the spare capacity of the pendulum type slide valve oil pump's ability to maintain pressure but costs a further 3psi loss crucially at higher rpm.
Oil escape from pressure fed bearings increases by roughly the square of the clearance....so even a small additional increase in clearance (through coating wear) will cause a significant increase in oil flow out of the bearing and thus further oil pressure loss.
Main bearing wear already seems to be marginal with normal oil pressure.

While I appreciate your confidence, I'm not so sure I share it.

[pbonsalb]

I don’t think low oil pressure is what causes the premature wear. You can change oil pressure 3 psi or more by changing brands of oil or oil weights. I have run 0W40 for the past 3-4 years.

[kawasaki00]

Originally Posted by doogee

Clevite Tri-Armor coatings wear off as well. Not even Clevite makes your claim. Clevite warranties it for 1 year.

I mean even if you look at an example above you'll see the coating failing at just 5000 miles.

You can't argue with facts or choose to believe what you want. I guess you could say all coatings suck .


You also seem to be confusing the actual bearing materials which are referred to as "Tri-Metal" with the coatings which are called "Tri-Armor". So you're talking about a made up coating that doesn't exist.

Yes I mis-typed about the tri-armour. The coating comes off because the overall design is still not good. Like I said coatings are band-aids. If parts are designed correctly you dont need coated bearings. Is it nice to have.. sure is it necessary. No it is not. That being said we chose to put the coating on the BE bearings because the design is fubar so in that case yes it is necessary.

Originally Posted by Sneaky Pete

Given that:
The use of BE extra clearance bearings not only uses up all the spare capacity of the pendulum type slide valve oil pump's ability to maintain pressure but costs a further 3psi loss crucially at higher rpm.
Oil escape from pressure fed bearings increases by roughly the square of the clearance....so even a small additional increase in clearance (through coating wear) will cause a significant increase in oil flow out of the bearing and thus further oil pressure loss.
Main bearing wear already seems to be marginal with normal oil pressure.

While I appreciate your confidence, I'm not so sure I share it.

While I get what you are saying 3psi is nothing. Also the pump is NOT at capacity even with BE bearings installed. I am not sure where you got that info but this graph shows that to be incorrect. If it was at capacity it would follow the imaginary red line that I put on it. The jitter in the pressure graph is the by product of a wet sump system. And the red line wil actually fall off harder than what I had drawn because as the flow cant keep up with the oil pump speed it will start to cavitate inside the pump and flow falls off along with pressure pretty hard.
The old design of 10psi per 1k rpm still holds true even today. Although in today's world we can get away with less the s65 still has over 80psi at 8500 with 0-40 and BE bearings.

Originally Posted by pbonsalb

I don’t think low oil pressure is what causes the premature wear. You can change oil pressure 3 psi or more by changing brands of oil or oil weights. I have run 0W40 for the past 3-4 years.

I have ran it for over 50k miles. Changed brands a time or 2 due to manufacturers always messing with the formula but same here.

[jcolley]

Originally Posted by doogee

And there is the completely blind defense that I was talking about lol.

You sir are operating on FAITH. Borderline cult.

Couldn't actually be the coating on the bearing failing right? Nooo it has to be installation error!


BE Bearings @ 5130 Miles. Coating significantly worn off for stated mileage. Upper left is especially bad. Keep in mind the areas that look worn in the center of the bearing appear to just be reflection of light. All the wear is closer to the parting lines.





VAC Bearings @ 33,500 Miles. Supercharged. No visible wear. 6.5X the mileage that are on the bearings above.






My argument isn't that BE Bearings are no good, I'm just proving that any evidence that is negative towards BE isn't acknowledged by anybody that is part of their cult. The bearing is just fine, but the coating is quite possibly junk.

I'll call bullshit on this one. The engine with these BE bearings is sitting 13.5 feet to my left at the moment waiting on head work to be complete. The rod bolts have not been torqued down yet. On no planet would anyone say the coating was worn off. You're making a lot of assumptions from my shitty Galaxy S7 pic and promoting them as fact.

[doogee]

Originally Posted by jcolley

I'll call bullshit on this one. The engine with these BE bearings is sitting 13.5 feet to my left at the moment waiting on head work to be complete. The rod bolts have not been torqued down yet. On no planet would anyone say the coating was worn off. You're making a lot of assumptions from my shitty Galaxy S7 pic and promoting them as fact.

Please post better photos and I'll gladly admit I'm wrong. I was surprised to see it myself. Whether the coating is wearing off or not doesn't even matter.

What are all the light colored areas around the parting lines?

Originally Posted by kawasaki00

Yes I mis-typed about the tri-armour. The coating comes off because the overall design is still not good. Like I said coatings are band-aids. If parts are designed correctly you dont need coated bearings. Is it nice to have.. sure is it necessary. No it is not. That being said we chose to put the coating on the BE bearings because the design is fubar so in that case yes it is necessary.

Definitely agree coatings are not necessary and carry a tad amount of snake oil.

[Sneaky Pete]

Originally Posted by kawasaki00

While I get what you are saying 3psi is nothing. Also the pump is NOT at capacity even with BE bearings installed. I am not sure where you got that info but this graph shows that to be incorrect.

I got it from this graph and the text below it.
There seems to be a crossover point where as oil flow increases the oil pressure drops.
Further increasing the oil flow out of the RBs is surely going to cause a further drop in oil pressure.
AIUI the oil pump has reached capacity when it is no longer able to supply oil at the pressure set by the spring loaded slide valve in the oil pump body...indicated by a drop in pressure.

[jcolley]

Originally Posted by doogee

Please post better photos and I'll gladly admit I'm wrong. I was surprised to see it myself. Whether the coating is wearing off or not doesn't even matter.

What are all the light colored areas around the parting lines?



Definitely agree coatings are not necessary and carry a tad amount of snake oil.

I don't have better photos and not really interested in disassembling it to clean the bearings up for a photo shoot. But I can promise if I thought there was any remote significance of the coating being worn, they wouldn't have gone back in to a motor I'm warrantying for rebuild to save a few hundred dollars.

There is a wear pattern near the parting line on several of the bearings, yes, but nowhere near worn through the coating. In fact, I spent a good amount of time trying to find the right camera angle to even show it.

The bearings which came out of this motor last year had similar wear near the parting lines as well. Sorry, don't have them still around for evidence, but thought it was strange then as well. On a decent percentage of the motors I'm inside, I see that wear. Of the 38 bearings jobs I've done on S85s in the last two years, I would say about 8 or 9 of them.

Wear at the parting line is a pretty easy thing to distinguish however from the normal wear pattern we see on these motors. The whole point of taking these and posting them at all was to show the absence of the usual wear pattern we see. I'll try and dig up a set of 14k WPC 702/703 photos that have a ton of the common wear.

IMO, coatings serve a different purpose than oil clearance. A bearing with proper oil flow will never need a coating. Of course, there's no such thing, every bearing in every engine has some rotation without film. The difference is what causes it.

It's the difference between assessing the cause of a problem and correcting it and applying a mitigation to a problem without determining cause.

[doogee]

Originally Posted by jcolley

I don't have better photos and not really interested in disassembling it to clean the bearings up for a photo shoot. But I can promise if I thought there was any remote significance of the coating being worn, they wouldn't have gone back in to a motor I'm warrantying for rebuild to save a few hundred dollars.

There is a wear pattern near the parting line on several of the bearings, yes, but nowhere near worn through the coating. In fact, I spent a good amount of time trying to find the right camera angle to even show it.

The bearings which came out of this motor last year had similar wear near the parting lines as well. Sorry, don't have them still around for evidence, but thought it was strange then as well. On a decent percentage of the motors I'm inside, I see that wear. Of the 38 bearings jobs I've done on S85s in the last two years, I would say about 8 or 9 of them.

Wear at the parting line is a pretty easy thing to distinguish however from the normal wear pattern we see on these motors. The whole point of taking these and posting them at all was to show the absence of the usual wear pattern we see. I'll try and dig up a set of 14k WPC 702/703 photos that have a ton of the common wear.

IMO, coatings serve a different purpose than oil clearance. A bearing with proper oil flow will never need a coating. Of course, there's no such thing, every bearing in every engine has some rotation without film. The difference is what causes it.

It's the difference between assessing the cause of a problem and correcting it and applying a mitigation to a problem without determining cause.

Thanks for the clarification. Totally understand pulling the bearings out again is a waste of your time!

Totally agree with you that a properly spec'd bearing doesn't need a coating. Mainly serves as a safety layer on cold starts etc.

I was never claiming that the bearings are no good because of the coating wear. It's going to happen period. I'll be doing a check on my VAC bearings shortly and if the coating has started to wear through it won't bother me as long as the bearing itself is in good shape. Depending on the wear pattern of course.

When is BE going to make a main bearing replacement for me I hope either BE or VAC is working on it, but I don't think they'd be interested for the size of the batch they'd need to sell.

[jcolley]

Originally Posted by Sneaky Pete

I got it from this graph and the text below it.
There seems to be a crossover point where as oil flow increases the oil pressure drops.
Further increasing the oil flow out of the RBs is surely going to cause a further drop in oil pressure.
AIUI the oil pump has reached capacity when it is no longer able to supply oil at the pressure set by the spring loaded slide valve in the oil pump body...indicated by a drop in pressure.

If you're referring to the point at around 4800 RPM where oil pressure begins to drop off, assuming your statement is correct and the pump is at capacity at that point, how would flow continue to increase?

[kawasaki00]

Originally Posted by Sneaky Pete

I got it from this graph and the text below it.
There seems to be a crossover point where as oil flow increases the oil pressure drops.
Further increasing the oil flow out of the RBs is surely going to cause a further drop in oil pressure.
AIUI the oil pump has reached capacity when it is no longer able to supply oil at the pressure set by the spring loaded slide valve in the oil pump body...indicated by a drop in pressure.

There is no drop in pressure on that graph though, the bypass valve is working just as it should.

[kawasaki00]

Originally Posted by jcolley

If you're referring to the point at around 4800 RPM where oil pressure begins to drop off, assuming your statement is correct and the pump is at capacity at that point, how would flow continue to increase?

The bypass regulator system was designed to provide said pressure off the stock flow rating. So when one ups the flow the bypass has no choice but to fall a few psi. If we could change the spring then the pressure would be the same with increased flow. Point being one cant keep pressure exactly the same while increasing flow without changing the bypass spring. If the pump really could not keep up a flow increase of 3gpm would cut the pressure by almost 25 percent

[Solo_M_Tech]

For the record, I think my 90k mile S65 had some of the worst wear I've seen on this forum. Old out, VAC in for a happy 26k miles with clean oil reports every 5k since. In my opinion, this forum has done more damage for this issue than benefit.

Note, sorry for the bad cell phone pic, but it's all I have.

[mmbv1000]

2008 e90 M3
60,500 miles
Daily driver but drive 5-7 miles per day... lots of short, city (stop & go) driving.
I always let her warm up for ~1 min then go slow until the oil comes up to temp.

Replaced with BE bearings and ARP bolts. The OEs looked pretty decent from the shot above, but all were worn near the top and edges... and pretty bad. I grabbed a few close-ups below. My last two blackstone analyses showed "higher-than-average" levels of lead in oil samples so I decided to just get this done along with OE motor mounts:

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[Sneaky Pete]

Originally Posted by jcolley

If you're referring to the point at around 4800 RPM where oil pressure begins to drop off, assuming your statement is correct and the pump is at capacity at that point, how would flow continue to increase?

The variable displacement oil pump is driven by engine speed...increasing rpm increases flow.
The problem isn't the minimal oil pressure drop shown on the extra clearance bearing graph.
The problem is that pressure drop is due to the oil pump's flow capacity being reached. Spare oil flow capacity originally engineered into the OEM spec to account for wear, high oil temperatures etc now exits the extra clearance bearings instead.
Consequently any wear of extra clearance bearing coating, elevated oil temps and/or use of a thinner oil will result in a further drop in oil pressure.

[pbonsalb]

And almost certainly won’t make any difference.