2011 S65 Main Bearings & Rod Bearings

[Shredicus]

Well here's hoping my EP oil additives like MoS2, ceratec and Archoil have helped with this shit >.>

[McSwine]

My indy shop I like a lot never mentioned the rod bearings but said I should consider changing the mains around 60-70K miles.

[Scharbag]

Originally Posted by 8500RPM

Not one bit. 1 has nothing to do with the other.

This has been discussed. There is some interdependency beteeen mains and rods.

Typically main pressure will drop a little if you open up the rod clearance. Main gross flow will increase but main net flow will decrease slightly.

It is likely such a small change that it will not matter.

Cheers,

[8500RPM]

Originally Posted by Scharbag

This has been discussed. There is some interdependency beteeen mains and rods.

Typically main pressure will drop a little if you open up the rod clearance. Main gross flow will increase but main net flow will decrease slightly.

It is likely such a small change that it will not matter.

Cheers,

[Jobe.]

I measured the crankshaft main journals, and rod journals as well.

The rod journals have four measurements for each journal since there are two rods per one journal.

A Fowler outside micrometer was used. This particular micrometer measures to ten thousands of an inch.

The measurements are from front to rear of the crankshaft. All measurements are in inches.

Mains
(1) (2) (3) (4) (5)
2.3763 2.3761 2.3763 2.3761 2.3768
2.3762 2.3762 2.3761 2.3764 2.3767

Rods
(1) (2) (3) (4)
2.0525/2.0523 2.0522/2.0529 2.0530/2.0522 2.0524/2.0522
2.0526/2.0520 2.0523/2.0525 2.0528/2.0524 2.0527/2.0522

The numbers are jumbled together once published....The numbers that are above/below one another are from the same journal.

[Solo_M_Tech]

Originally Posted by Jobe.

I measured the crankshaft main journals, and rod journals as well.

The rod journals have four measurements for each journal since there are two rods per one journal.

A Fowler outside micrometer was used. This particular micrometer measures to ten thousands of an inch.

The measurements are from front to rear of the crankshaft. All measurements are in inches.

Mains
(1) (2) (3) (4) (5)
2.3763 2.3761 2.3763 2.3761 2.3768
2.3762 2.3762 2.3761 2.3764 2.3767

Rods
(1) (2) (3) (4)
2.0525/2.0523 2.0522/2.0529 2.0530/2.0522 2.0524/2.0522
2.0526/2.0520 2.0523/2.0525 2.0528/2.0524 2.0527/2.0522

The numbers are jumbled together once published....The numbers that are above/below one another are from the same journal.

According to the numbers, the crankshaft journals are in great condition, and round. Very good to see. Variances of 0.0001" are considered normal when measured by hand, since human error is a factor and it's almost impossible to get the micrometer directly centered on the journal. Even the slightest oil film can throw off those measurements at the ten-thousandths level.

On another note:

So what can we learn from this thread..... It's time to hype up main bearing failure and everyone rush out and change their main bearings asap!

[Bartledoo]

Can we get a stroker/cam build group buy going?

[kyrix1st]

These engines need recalls

[8k_v8]

Originally Posted by kyrix1st

These engines need recalls

Miracles can happen! Look at all the VW Buybacks because of the emissions scandal.
I'm sure internally they laughed when people asked for their money back on those cars....until CARB and the feds started calling haha

[drwankel]

While the main bearings don't look great, I am somewhat comforted about the lack of main bearing failure posts I see on this forum. I've seen rod bearing failure posts, but rarely/never mains.

None the less, the condition of those main bearings are certainly concerning. Makes me feel not so great about the prospect of long term lifespan with a supercharger.

[drwankel]

Originally Posted by inTgr8r

The issue with mains replacement is that there is no 'fix' as there is with rod bearings with more clearance.

With mains change you are just starting the wear cycle over again.
If that's all we're doing then the trick is to determine the mtbf life cycle for them.

E.g. There is no point changing them at 30k if they're known to be good for 80k
Wait for 80 , then you get another 80 after that.

The problem right now is there isn't enough data.

I am interpreting this as there is no fix as nobody actually makes main bearings with increased clearance. Hypothetically someone like BE bearings could make a higher clearance main bearing set that may alleviate the issue?

[BayE30]

Are the main bearing made out the same material as rod bearing? Do the main bearings have the same material change between pre and post LCI? Interested to know if this can be caught by oil samples, or if the LCI guys are up shit creek ala rod bearings...

[SYT_Shadow]

Originally Posted by drwankel

While the main bearings don't look great, I am somewhat comforted about the lack of main bearing failure posts I see on this forum. I've seen rod bearing failure posts, but rarely/never mains.
.

This

Maybe rod bearings are in the 1% failure rate, but mains? 0.1%?

It's far from being a concern at this point, especially due to how hard it is to swap them out

[SYT_Shadow]

Originally Posted by drwankel

I am interpreting this as there is no fix as nobody actually makes main bearings with increased clearance. Hypothetically someone like BE bearings could make a higher clearance main bearing set that may alleviate the issue?

Yes, someone could make increased tolerance bearings but I don't think there's enough demand out there

[deansbimmer]

Mains should always be same material as the rod bearings. There should not be any mixed sets from a factory assembly.

Don't hold your breath for a set of aftermarket mains. We've been told in other threads that main bearings would require significantly more tooling costs as there are four molds instead of two *per size set*, plus the minimum purchase quantity from the factory. That's a major 6 figure investment for not much demand.

[Duk996]

If your really hell bent on replacing the bearings and increasing the clearance you can always try and play the color game with them...

[Iyzmi]

Originally Posted by McSwine

My indy shop I like a lot never mentioned the rod bearings but said I should consider changing the mains around 60-70K miles.

Find a new indy shop, this one doesn't sound like they are very familiar with the S65. Or they're trying to get you to bend over and pay for a 30hr+ main bearing swap.

[aswy6]

Originally Posted by deansbimmer

Mains should always be same material as the rod bearings. There should not be any mixed sets from a factory assembly.

Don't hold your breath for a set of aftermarket mains. We've been told in other threads that main bearings would require significantly more tooling costs as there are four molds instead of two *per size set*, plus the minimum purchase quantity from the factory. That's a major 6 figure investment for not much demand.

Sorry for stupid question but just want to clarify something for myself. What do you mean by same material? If my car is 2011 and i have aluminum bearings, would it not be good to swap fro BE which are different material?
Thank you

[deansbimmer]

Originally Posted by aswy6

Sorry for stupid question but just want to clarify something for myself. What do you mean by same material? If my car is 2011 and i have aluminum bearings, would it not be good to swap fro BE which are different material?
Thank you

I was responding to a question above. It doesn't matter if you later on replace the bearings with a different material.

Are the main bearing made out the same material as rod bearing? Do the main bearings have the same material change between pre and post LCI? Interested to know if this can be caught by oil samples, or if the LCI guys are up shit creek ala rod bearings...

[Scharbag]

Originally Posted by Duk996

If your really hell bent on replacing the bearings and increasing the clearance you can always try and play the color game with them...

Or if you want to get really serious, have your crank machined and re-hardened... Yuck.

[loveskiing]

Originally Posted by SYT_Shadow

If you ever want to do this I'm down to help

We can create a main bearing DIY

Cool bro...I'm only at 35k but when I get closer to 80k I'll let you know. I'm assuming you have your own tools and can get here to Portland Oregon on your own, right?

[SYT_Shadow]

Originally Posted by loveskiing

Cool bro...I'm only at 35k but when I get closer to 80k I'll let you know. I'm assuming you have your own tools and can get here to Portland Oregon on your own, right?

You're a bit far! But we do have a plant right there so I visit PD every now and then.

Wouldn't be the first time I travel with an entire suitcase full of tools