Official S65 Bearing Specification/Clearance Wiki

[klammer]

Wow! Wow! Wow! This is an awesome thread! I just rolled past 50k and with all the hard miles put on, I will definitely be addressing this. Just unanticipated maintenance brought to our attention by this "best thread ever"!

[V8FunNaturally]

Originally Posted by jcolley

I've been emailing Sam at AutoTalent and he confirmed about $4/bearing

I did not realize a rod bearing is so cheap (machining the crankshaft isn't). Sorry if I missed or forgot the point buried somewhere in the discussion but isn't there some merit in the question also found in the original thread as to why couldn't Mahle-Clevite or another OEM and after market engine parts manufacturer start the design and production of a "replacement" rod bearing for increased clearances if the number of failures observed foretold a real market for it ? They could even sell these at a much higher profit margin than their OEM "volume" parts, why would they / have they not jumped on it ?

The technical probing and volunteering of information and insights given by forum members deserve praise, but I do not see clear evidences that a significant number of stock engines have failed in so many years. Is it 1 in a thousand ? If the problem had started to be known publicly in 2011, then bmw who has the full database of failed engines was certainly on it too and would have made changes to new cars for 2012 and 2013 model years. Especially if any significant numbers of stock engines under warranty had failed in numbers but I see the large majority of these examples are SC. How many known stock engines failures are we talking about grand total ? 3, 5 ?

[regular guy]

Originally Posted by sunsweet

I did not realize a rod bearing is so cheap (machining the crankshaft isn't).

That's $4 for WPC treatment on each bearing. You still have to buy the bearings themselves. But yes, $400 is cheaper than machining the crank.

The technical probing and volunteering of information and insights given by forum members deserve praise, but I do not see clear evidences that a significant number of stock engines have failed in so many years. Is it 1 in a thousand ? If the problem had started to be known publicly in 2011, then bmw who has the full database of failed engines was certainly on it too and would have made changes to new cars for 2012 and 2013 model years. Especially if any significant numbers of stock engines under warranty had failed in numbers but I see the large majority of these examples are SC. How many known stock engines failures are we talking about grand total ? 3, 5 ?

If only supercharged motors were experiencing rod bearing failure, then nobody would be investigating -- I know I wouldn't. The fact that so many NA engines are having rod bearing failure was my motivation for trying to figure out why it's happening. Since it was my engine builder who made the discovery and alerted me to the problem, I wanted to know how much evidence I could find. I also wanted to verify his measurements with those of my own.

As of now, there are many orders of magnitudes of NA motors failing than supercharged motors. As I mentioned in the top articles, if you made it past 25000 miles, then you would likely make it past your entire warranty period. All along, I have been speaking of NA motors, not supercharged motors, though I will include photos of supercharged bearing failures as well in the photo database.

Over the past five years, I've probably seen 25-30 failed NA engines on this forum, not just 3-5. I think I've already posted pictures of five, and have many more to go. Most M3 owners aren't on the forums, so you don't hear about the problems. Last week alone, our local dealer had three M3's with rod bearing failure. Two months ago, a local guy blew his engine with rod bearing failure and punched a hole in the side of his block. Three days ago, it happened to another local buddy. All of these are NA cars under warranty -- and all just in my own area. None of them are supercharged.

Even if BMW knew there was a problem, I don't see them changing the engine design unless it's financially cheaper than replacing engines under warranty. A recall has all kinds of negative financial consequences, and changing the design without a recall could lead to a class action lawsuit and plumetting sales, etc. So BMW isn't going to change the design without a recall; they'd rather roll the dice and know that 99% of all engines will make it out of warranty even if 1% don't.

This Wiki thread was created to spread information about rod bearing clearance and measurements. The clearance issue was discovered without looking for it. But once it was found, it became a very compelling set of evidence to explain so many NA engine failures. But the story isn't over yet, there's another shoe about to fall. Bearing clearance isn't the only problem we discovered. Hopefully I'll have time to gather the pictures and write that article tomorrow.

[BIU]

Thread of the century?

[e92zero]

Originally Posted by regular guy

But the story isn't over yet, there's another shoe about to fall. Bearing clearance isn't the only problem we discovered. Hopefully I'll have time to gather the pictures and write that article tomorrow.

Another shoe to fall? That's not encouraging.

But it looks like the best/most economical option we have for now is to change to the WPC bearings. Any recommendation on sticking to the TWS or M1 0-40 if we use the WPC bearings? regular guy, kawasaki00, BMRLVR?

On a side note, I wonder if any one has the clearance info/data from porsche/ferrari/audi high reving engines for comparison purpose given they use different/thinner oil? I thought the R8 uses the same TWS though. Not sure if it's completely relevant.

[aus]

Originally Posted by sunsweet

I did not realize a rod bearing is so cheap (machining the crankshaft isn't). Sorry if I missed or forgot the point buried somewhere in the discussion but isn't there some merit in the question also found in the original thread as to why couldn't Mahle-Clevite or another OEM and after market engine parts manufacturer start the design and production of a "replacement" rod bearing for increased clearances if the number of failures observed foretold a real market for it ? They could even sell these at a much higher profit margin than their OEM "volume" parts, why would they / have they not jumped on it ?

The technical probing and volunteering of information and insights given by forum members deserve praise, but I do not see clear evidences that a significant number of stock engines have failed in so many years. Is it 1 in a thousand ? If the problem had started to be known publicly in 2011, then bmw who has the full database of failed engines was certainly on it too and would have made changes to new cars for 2012 and 2013 model years. Especially if any significant numbers of stock engines under warranty had failed in numbers but I see the large majority of these examples are SC. How many known stock engines failures are we talking about grand total ? 3, 5 ?

You must be new here?

http://www.m3post.com/forums/showthread.php?t=786615

These are blown motors and doesn't include all the trashed bearing cars that have been posted here.

.

[IMG]

This is very informative. I will be sending my bearings to Regular Guy to measure them and add the measurement to this great thread.
They are coated bearings and got 30k of hard driving.
Awesome thread man !

[jcolley]

Originally Posted by e92zero

Another shoe to fall? That's not encouraging.

Indeed...the Imelda Marcos of the automotive world.

Originally Posted by e92zero

Any recommendation on sticking to the TWS or M1 0-40 if we use the WPC bearings? regular guy, kawasaki00, BMRLVR?

Curious about this as well; sending bearings to AutoTalent this week.

[aussiem3]

Originally Posted by kawasaki00

The Dinan stroker kit opens the rod bearing clearance up while using the stock oil pump. There is not a problem with the pump keeping up.

I noticed that you mentioned 5w-60. We have that in Australia, and I would appreciate your thoughts on the properties of it.

For this problem we have if there were a 5w-60 that would be the ultimate for us. Unfortunately there is no such grade. The 5w would help a ton at start up but still protect like a 60 weight at temp. This is why the rotella 5-40 is a trade off. It is better at low temps and flows better but the untimate high temp shear strength is not as much as a 60.
The second number is the protection factor not the weight. A 10w-30 and a 10w 60 is till the same weight at cold temp. -- kawasaki00

http://www.penriteoil.com.au/product...d_products=281

[kawasaki00]

Originally Posted by aussiem3

I noticed that you mentioned 5w-60. We have that in Australia, and I would appreciate your thoughts on the properties of it.



http://www.penriteoil.com.au/product...d_products=281

VISCOSITY (cSt @ 100oC): Typically 23.8.
VISCOSITY (cSt @ 40oC): Typically 146.
FLASHPOINT (oC): Typically 220oC.


Even though it is marketed as a 5wt is is thicker than tws cold and hot. I would not run it. Most tws tests come back around 140 cold.

[aussiem3]

Originally Posted by kawasaki00

VISCOSITY (cSt @ 100oC): Typically 23.8.
VISCOSITY (cSt @ 40oC): Typically 146.
FLASHPOINT (oC): Typically 220oC.


Even though it is marketed as a 5wt is is thicker than tws cold and hot. I would not run it. Most tws tests come back around 140 cold.

Thank you

[aus]

I was at AutoTalent yesterday for my wife's car and they had no idea what I was talking about when I asked about the bearings for our car. Maybe it was an old project for them, likely PencilGeek's car since they've been working on it forever? I know they've got tons of different cars to work on. That place is just eye candy for a Euro car guy.

I asked Sam and Zolti.
Strange.

.

[Wendall]

Originally Posted by aus

I was at AutoTalent yesterday for my wife's car and they had no idea what I was talking about when I asked about the bearings for our car. Maybe it was an old project for them, likely PencilGeek's car since they've been working on it forever? I know they've got tons of different cars to work on. That place is just eye candy for a Euro car guy.

I asked Sam and Zolti.
Strange.

.

Thats funny, I emailed Sam yesterday and he knew exactly what I was talking about. He actually said he was currently negotiating with ARP for bolt prices as he expects to do many WPC rod bearing changes in the future. He gets the bearings for a discounted rate.

[lsmkr01]

Originally Posted by aussiem3

Couldn't agree more. I am doing an oil change this weekend and planning to send the oil for analysis. The car is an '07 with 39k km and has been on this oil since December 12 with just 5k km. Anxious to see the results.

By the way, great information.

You only drove your car 3.2k miles in almost a full year???

[aussiem3]

Originally Posted by lsmkr01

You only drove your car 3.2k miles in almost a full year???

It's a weekend warrior. I We have an '11 X3 we drive to work everyday. 3984 km to be precise in 10 months. Normally I go for long drives on the weekends. But this year I've been extremely busy, and we've had an extended winter, with the weather being an absolute bugger.

Regardless, I would like to see any wear pattern.

[sensi09]

Are there any instances of BMW covering rod bearing failure outside of warranty?

[regular guy]

Connecting Rod Side Clearance Issues

Discovering rod bearing clearance issues wasn't the only adverse discovery we made while assembling this motor. In addition to measuring bearing clearances, Van Dyne also measures connecting rod side play, crankshaft end play, valve opening/closing angles, valve spring seat pressure, and many other things. Connecting rod side clearance is measured by sticking a feeler gauge between the connecting rods to see how much space is between them. Engine builders like to see the connecting rod side clearance in a very specific measurement range. The measurement is taken when the bottom end is mostly assembled: the crankshaft is in place, and the pistons and connecting rods are attached and torqued down. If the side clearance is too little, then oil cannot escape and extra heat is generated by the friction of the connecting rods colliding against each other.

The crankshaft itself can be damaged as well. When the rod side clearance is too tight, as the engine heats up, the rods will swell and the crank will shrink. The tight clearance gets smaller and smaller until the rods collide and start riding against the crankshaft journal fillet. The fillet can be worn down, and damaged by this process, and the metal shavings it produces will damage the connecting rod bearings and other engine parts as well.

To measure the connecting rod side clearance, Van Dyne instinctively grabbed the feeler gauge for the normal, industry-accepted side clearance measurement. The feeler gauge wouldn't fit. Van Dyne grabbed the next feeler gauge half the thickness of the first: it still wouldn't fit. He then grabbed the next feeler gauge half that size: it still wouldn't fit. After four different tries, Van Dyne finally found the feeler gauge that fit. The side clearance was approximately 1/4 the size of industry expected clearance. The clearance was the thickness of two human hairs.

Without hesitation, Van Dyne grabbed our spare set of Carrillo rods that had been in the motor previously. He grabbed them as if he expected to find evidence of possible damage. Within a split second, Van Dyne pointed to the side of the Carrillo rod and said:

See that tiny blue spot? That's caused by heat from these two rods rubbing together because they are so tight. See that scrape mark? That's also caused by these two rods rubbing together.

As Van Dyne (and kawasaki00) explained, proper rod side clearance is essential to allow oil to escape. As the engine heats up, the connecting rods grow and the crankshaft shrinks until the connecting rods are touching each other. The oil can't escape, and extra heat is generated by the friction of the connecting rod collisions. The side of the crankshaft journal could also be damaged by the collisions as well. To me, the situation sounded pretty serious, and I thought it was going to mean another multi-week setback for the project.

Van Dyne deemed the situation so serious that he asked if we could go 60-minutes across town and bring back a factory BMW crankshaft (ours was a billet "stroker" crankshaft) and some factory BMW connecting rods (we were working with two sets of Carrillos). Van Dyne wanted to measure the factory journal width, and factory connecting rod thickness to see if the stroker crankshaft or Carrillo connecting rods were to blame.


Measuring Connecting Rod Side Clearance

Almost in disbelief, Van Dyne started taking measurements. First he measured with a set of calipers. Then when he realized the measurement didn't lie, Van Dyne knew he had to take accurate measurements with micrometers so he could make the necessary calculations to fix the problem.



To make sure the measurements are accurate, first the micrometers were calibrated to a known good thickness.



Van Dyne then started to measure both crankshafts: our billet crankshaft, and the factory crankshaft. The journal thickness measurements both matched. Next, we need to check the connecting rods to see if the Carrillo's were machined thicker than factory rods.



Following the crankshaft measurements, Van Dyne measured the connecting rods to see how they compared. Van Dyne measured both Carrillo and factory connecting rods.



The measurements showed the Carrillo and factory connecting rods are the same thickness. This is positive proof that the factory BMW crankshafts are machined without enough rod side clearance AND without enough rod bearing clearance. It's a double-whammy against proper engine oiling and operation.



Finally, Van Dyne set out to "fix" the clearance issue. I was relieved when Van Dyne said he could fix the issue immediately – as I feared project would suffer another long delay. Without hesitation, Van Dyne pulled out the bottle of DYKEM and started color coating one side of the connecting rods. This would be the side he planned to machine, and the DYKEM would serve as a visual reminder which connecting rods were finished, and which ones weren't.




Van Dyne's machine shop was able to grind down each connecting rod to the exact specification he wanted. When he reassembled the bottom end a few hours later, the measurements all agreed. The rod side clearance issue was now fixed.

What does this mean to you?

To get second opinion of the seriousness of this issue, I emailed kawasaki00 and I shared the actual specs with him (I'm not sharing them here). I asked if this was a big issue or not. Without hesitation, kawasaki00 agreed with Van Dyne that this was indeed a big issue, and he thought I was lucky to have an engine shop capable enough to measure and fix this problem. As he said, we really dodged a bullet.

I'm not an engine builder -- so I'll let kawasaki00 and BMRLVR chime in to answer questions on this topic. But I can put the pieces of the puzzle together and tell you what they mean to me. BMW gave you the thickness of two human hairs to let the oil squeeze out of the connecting rods. I don't think it takes an engine builder to realize that oil can't escape with side clearance that small. It makes me wonder how heated that trapped oil might get and how fast it might wear out my bearings -- bearings that already suffer from too little clearance of their own. Then with the connecting rods scraping against each other after they swell and the crankshaft shrinks, I can also see how metal shavings could get generated to destory the bearings and other engine components.

In the next few weeks, I'll share some photos of catastrophic engine failures. But for now, I'll leave you with the photos of the micro "blue marks" and abrasive scuff marks left on my Carrillo connecting rods from the previous engine build with improper side clearance -- compliments of BMW engineering.

1	1	2	2	3	3	4	4
5	5	6	6	7	7	8	8

A few of the photos above are recreations because I didn't take actual photos of the calibration process, nor the actual scuff marks on the day of the engine build. I took those photos today to show what the process looks like. The scuff marks are the actual scuff marks on the same Carrillo connecting rods.

Complete photo library on this issue:

More photos are available at the following links.
Instrument Calibration and Connecting Rod Measurements
Side Play Clearance Measurements
Side Play Clearance Adjustments
Side Play Scuffing Evidence

[e92zero]

really appreciate the effort for the write up and the sharing of the data but this is not encouraging for the s65. I am guessing there is no easy work around/bandit for this rod side clearance issue? Would running thinner oil help here too?

On a sarcastic/funny note, so if the engine is cold, oil might not be able to get to the rod bearings for lubrication and cause the bearings to wear. If the engine is hot (too hot?), the rods side might close up and prevent oil escaping which will probably cook the oil inside the rod bearing and then destroy the bearing? This is our beloved s65 that won the engine of the year for all those years straight.

I will still keep this car/engine though.

[Yellow Snow]

RG: In your original M5 board teardown thread, it says the Carillo rods were the same thickness as the S65 rods and they were only reground for the specifics of the stroker build. Nothing was said about only having a .003" side clearance.

If the standard side float is deemed as being too little, wouldn't Carillo make their rods thinner?

Did Van Dyne say at the time that this would cause a problem on a stock engine?

http://www.m5board.com/vbulletin/e90...r-motor-2.html

Anyway. I have done some more accurate measurements of both the red and blue bearings and have found them both to be almost exactly the same size! This must mean the discrepancy between the two must be down to material softness.

Measuring a soft bearing is difficult with a mic of any sort. I measured the same bearings with a mic and found them to be different.

To get an exact no quibble size, I set up a reference grade 2mm slip gauge at 20 degrees C.



Red bearing is .0003" (3 tenths) smaller than 2mm. ie .07844" or 1.992mm



Blue bearing is pretty much exactly the same. which gives a total .0006" (6 Tenths) clearance on the nominal sizes, plus journal and rod clearances .

[thekurgan]

Now with this new information regarding small clearances, I'm even more concerned about a 60 weight oil in this pig.

[kiln]

This raises the next question. Who is going to sell a stroker kit with all the proper machining for clearances.

[L4ces]

Originally Posted by kiln

This raises the next question. Who is going to sell a stroker kit with all the proper machining for clearances.

+1