Official S65 Rod Bearing Condition Example Thread

Assimilator1 wrote

IamFODI
As you know I largely agree with you, but I pick you up again on the term discolouration .
Wear on the micro grooves shows that it is not just a colour change (say from some chemical reaction) but physical wear, albeit to a light degree.

1. Most people aren't reacting to a close analysis of the bearing surface. They're looking at (pics of) the bearings from more than a foot away, seeing some vaguely coppery coloration, and concluding from that that the bearings are shagged. By calling out the discoloration, I'm pointing to the thing people tend to use as their criterion for critical wear. If "people" doesn't include you, then I'm not addressing you.

2. Most of this discussion is dominated by low-resolution representations. So far, the main alternative to "discoloration" is "excess wear." Both technically incorrect, but the latter is more incorrect given the obvious connotations of the word "excess."

How about a phrase like "light surface wear” instead?

Assimilator1 wrote

Higher flow rate due to bigger rod bearing clearance necessarily means lower pressure within the rod bearings themselves, at least on average

I don't know why you say that when the variable volume pump compensates for the greater flow, so therefore no pressure drop in the rod bearings, and no issues for the mains.
Am I missing something?

Well, let's ask BE:

We could expect that increasing bearing clearance might decrease oil pressure.

When we change bearings from factory to BE Bearings with increased clearance, there may be a slight drop in oil pressure due to the larger bearing clearance.

Our hopes with BE Bearings were to allow a modest drop in oil pressure, so long as it was accompanied by an increase in oil flow.

Yes, in theory, pump regulation might be able to compensate. But it’s not like the pump can reach into the engine and selectively compensate for pressure loss in one specific location. If it had sensors downstream of the rod bearings (or at least closer to them in the system) that could feed back on the pump, then yeah, maybe. But all it can sense and correct for are the pressure and volume very close to its outlet. It's not a given that a pressure loss at the rod bearings – after the oil filter assembly, oil cooler, and main bearings – will be "felt" sufficiently at the pump for the pump's reactions to fully compensate for it.

Worth noting that BE did measure a pressure loss even with sensors well upstream of the rod bearings:

Oil pressure does seem to decrease slightly with BE Bearings. This is most likely due to the extra clearance... [t]he amount of decrease is between 2-3 PSI, over a 70+ PSI average. Assuming the 73 PSI average, a 3 PSI pressure drop is equal to 4% of the total.

Not a huge loss by any means. But we should remember that, for the aforementioned reasons, this means a pressure loss of at least that much everywhere else in the system – likely more at the source of the pressure loss (i.e. the rod bearings) and adjacent parts (e.g. the mains).

MY 10. Was a single owned car in Seattle, garage kept for life. Driven roughly 3k miles/yr but for the last few years even less. Oil changes every 3-5k miles or yearly if less. I bought it shy of 19k miles and did the BE bearings at 19,9xx at ACM. I'm sure the original owner always warmed it but you never know. And I also don't know if he took it for short or longer drives but I highly doubt he abused the car. Was owner by a senior citizen. I figured these would be copper bearings but they look Al to me even though the car has a 09/10 build date I believe. I will take more detailed pics of each bearing when I get back to town

Reddevils7 wrote

MY 10. Was a single owned car in Seattle, garage kept for life. Driven roughly 3k miles/yr but for the last few years even less. Oil changes every 3-5k miles or yearly if less. I bought it shy of 19k miles and did the BE bearings at 19,9xx at ACM. I'm sure the original owner always warmed it but you never know. And I also don't know if he took it for short or longer drives but I highly doubt he abused the car. Was owner by a senior citizen. I figured these would be copper bearings but they look Al to me even though the car has a 09/10 build date I believe. I will take more detailed pics of each bearing when I get back to town

Yep, those are the newer style bearings. And, predictably for the mileage, the ones with their surfaces visible look cherry.

FYI, these have copper, too. What they don't have (that the originals had) is lead.

IamFODI wrote

Yep, those are the newer style bearings. And, predictably for the mileage, the ones with their surfaces visible look cherry.

FYI, these have copper, too. What they don't have (that the originals had) is lead.

Yeah these have copper too but you shouldn't ever see it, correct? If you're seeing copper in the new ones that means there's severe multi layer wear? I agree, my bearings look pretty good and they didn't really need to be changed but I'm keeping this car long term so it's giving me peace of mind. Don't have to worry about blowing a rod when revving it out all the way to 8k and can actually enjoy the car lol. I did a handful of upgrades at the same time and it's tough resisting taking it past 3.5k rpm before it's fully broken in lol

Reddevils7 wrote

Yeah these have copper too but you shouldn't ever see it, correct? If you're seeing copper in the new ones that means there's severe multi layer wear?

That's a bit oversimplified but... yeah, basically. It's not like your engine will grenade the moment you hit copper, but at that point you're definitely on borrowed time.

That's true of all trimetal bearings but especially these. We've apparently never seen the new ones show copper in anything like normal use (including track use). So yeah, I'd say if these bearings ever show copper, something's SERIOUSLY wrong (or the engine has like 500k miles on it).

Anyway, best of luck!

Reddevils7 wrote

Yeah these have copper too but you shouldn't ever see it, correct? If you're seeing copper in the new ones that means there's severe multi layer wear? I agree, my bearings look pretty good and they didn't really need to be changed but I'm keeping this car long term so it's giving me peace of mind. Don't have to worry about blowing a rod when revving it out all the way to 8k and can actually enjoy the car lol. I did a handful of upgrades at the same time and it's tough resisting taking it past 3.5k rpm before it's fully broken in lol

There's no break-in period for bearings. That's meant for piston rings. Redline that engine!

jvictormp wrote

There's no break-in period for bearings. That's meant for piston rings. Redline that engine!

Yeah idk about that lol it's definitely an investment so I'd rather play it safe and take it easy in the beginning. I was advised by ACM to do an oil change 800-1000 miles after the work and send them a receipt to ensure their work is warrantied. Makes sense to me to flush out any potential metal shavings before fully enjoying the car

jvictormp wrote

There's no break-in period for bearings. That's meant for piston rings. Redline that engine!

Glyco thinks there is. E.g.:



https://www.m3post.com/forums/attachment.php?attachmentid=2269856&d=1585407712

Reddevils7 wrote

MY 10. Was a single owned car in Seattle, garage kept for life. Driven roughly 3k miles/yr but for the last few years even less. Oil changes every 3-5k miles or yearly if less. I bought it shy of 19k miles and did the BE bearings at 19,9xx at ACM. I'm sure the original owner always warmed it but you never know. And I also don't know if he took it for short or longer drives but I highly doubt he abused the car. Was owner by a senior citizen. I figured these would be copper bearings but they look Al to me even though the car has a 09/10 build date I believe. I will take more detailed pics of each bearing when I get back to town

You sure it's a MY10? I have a MY'11 and it has a build date of 07/10. I too had the newer bearings.

serranot wrote

You sure it's a MY10? I have a MY'11 and it has a build date of 07/10. I too had the newer bearings.

Yeah it's 10/09 build date my bad

IamFODI wrote

Glyco thinks there is, at least for some of their rod bearings:



https://www.m3post.com/forums/attachment.php?attachmentid=2269856&d=1585407712

Is that the little table in page 27 your referring to? I always struggle to find that in that huge, detailed doc

Btw, re oil pressure loss, I should have said 'no significant pressure loss' with the BE bearings.

And yea, light surface wear sounds good I think:thumbsup:

IamFODI wrote

Glyco thinks there is, at least for some of their rod bearings:



https://www.m3post.com/forums/attachment.php?attachmentid=2269856&d=1585407712

If there was supposed to be an image in the post, it didn't work here. Don't know if it's my computer or the post itself. But the document worked well.

Anyway, if you're talking about page 27 of it, (as Assimilator1 said), I must say it's a good point because Glyco isn't a nobody like me, although the document itself let us blind by telling no argument to support that affirmation.

To build an argument against, I bring this video below, @0:45

Not that it should be an unquestionable truth, but it's an argument.

Assimilator1 wrote

Is that the little table in page 27 your referring to? I always struggle to find that in that huge, detailed doc

jvictormp wrote

If there was supposed to be an image in the post, it didn't work here. Don't know if it's my computer or the post itself. But the document worked well.

Anyway, if you're talking about page 27 of it, (as Assimilator1 said), I must say it's a good point because Glyco isn't a nobody like me

Thanks, guys. Think I fixed the pic.

jvictormp wrote

although the document itself let us blind by telling no argument to support that affirmation.

Exactly. In a document aimed at describing their bearings and offering guidelines for how to use them, it didn't even occur to them to try to justify the idea that bearings break in. They just kind of take it for granted.

Let that sink in for a second.

Assimilator1 wrote

Btw, re oil pressure loss, I should have said 'no significant pressure loss' with the BE bearings.

The measured pressure loss definitely isn't large. But saying it's not "significant" implies that it has no meaningful effect, and we don't know that yet.

jvictormp wrote

To build an argument against, I bring this video below, @0:45

Andre's great. But you're not seriously suggesting his word about bearings is as credible as that of a literal bearing developer/manufacturer, are you?

IamFODI wrote

Exactly. In a document aimed at describing their bearings and offering guidelines for how to use them, it didn't even occur to them to try to justify the idea that bearings break in. They just kind of take it for granted.

Let that sink in for a second.

Only now I came to notice that we are discussing about a 4-minute running-in programme.

Thought we were talking about a 500~1,000 miles break-in.

4 minutes are pretty acceptable.

jvictormp wrote

Only now I came to notice that we are discussing about a 4-minute running-in programme.

Thought we were talking about a 500~1,000 miles break-in.

4 minutes are pretty acceptable.

Yep.

Though, still a few more things to note:

1. The main point is that 4 minutes is a lot more than zero. No one's saying rod bearings take "very little" break-in; they're saying rod bearings take "no" break-in because there should be absolutely zero metal-to-metal contact in normal operation. Zero means zero – not even light grazing of surface asperities. That's obviously false.

2. If you translate this recommendation from Glyco into actual running time in the hands of someone who just got their car back from the shop with new rod bearings and instructions to "go easy on it," you could easily end up with hundreds of miles. The recommendation is four total minutes across three different RPM bands, one of which is half the engine's redline. Most of us spend very little time at half of redline even when our engines are completely broken in. Like, a second at a time. How long might an average person take to rack up a full minute of half-redline runtime when they've been told to go easy on the engine? I'm betting we'd be surprised.

I'll counterpoint myself here: this recommendation from Glyco is in a section about their "Sputter" bearings, which are apparently hard-wearing and take longer to break in:

On the other hand, the hard Sputter layer’s high wear resistance means that it adapts more slowly to the unevenness of the crankshaft’s surface.

Bearings with softer top layers should take less time.

But, again, not zero. Whether there's metal-to-metal contact is determined by the oil film, which is determined by the bearing's dimensions and the oiling system – not the bearing material. This is presumably why Glyco says "Sputter bearings take longer", implying that all bearings do the same but possibly in less time – instead of saying something like "Sputter bearings need to break in."

jvictormp wrote

There's no break-in period for bearings. That's meant for piston rings. Redline that engine!

Speaks the truth!

What's the consensus on doing an oil change after bearings? My shop wants me to do one within 800-1000 miles and send them proof as part of the warranty of the work. He told me it's for any potential metal shavings which makes sense to me. I'm at 800 miles but oil change isn't till next Thursday. I'd do it myself if I was at the house garage. I'm just itching to finally unleash the car and it doesn't help that I had also gotten the AA x pipe installed at the same time lol can't wait to finally hear the car

If that’s what they need for their warranty coverage just do it. But nobody will ever convince me that rod or main bearings require break in.

Changed mine at 500 miles because it had been a year since the oil change. I would do it either yearly or 3k miles. Mine had zero flakes in it.

These are more close ups. Again, done at 19,9xx miles. I'm the second owner. The code shows they're 088/089 so these are pre lci bearings with less clearance, correct me if I'm wrong. Car build date 10/09. The last few pics are of bearings I thought had more wear as it looked like there were 2 different layers present

Reddevils7 wrote

These are more close ups. Again, done at 19,9xx miles. I'm the second owner. The code shows they're 088/089 so these are pre lci bearings with less clearance, correct me if I'm wrong. Car build date 10/09. The last few pics are of bearings I thought had more wear as it looked like there were 2 different layers present

Mine had less wear than that at 49000 miles

Do the bearings have to be replaced every 50-60k miles after the first replacement? Is the problem poor bearings or an engine prone to excessive bearing wear?