Lang Racing on the S54 Rod Bearing problems

[kawasaki00]

Originally Posted by M3PO

As everyone else has said numerous times, the first single revolution will have NO OIL regardless of what oil you run. The overwhelming majority of wear happens as the oil is warming up. This is where oil choice is important.

Can we please just move on now?

Every engine in every automobile is the same way, just because we feel our car is special, in this aspect it actually is not special.

[FogCityM3]

For what it's worth, I remember watching a video with Steve Dinan talking about the S85 (or S65, can't remember exactly which one), and he claimed that BMW believes the engine is good for 150k miles..he went on to say it was his expectation that a tuned engine with full Dinan mods would shorten the lifespan by 20-25k miles.

Originally Posted by bigjae1976

But you bring up an interesting point about life expectancy of the engine. I think 100k - 120k on an M engine is normal. In fact, its gotten much better since the days of the S38 and S14 and even the S62. You can see this based on resale values for the E46 M3 which from my observation are heavily penalized for high mileage. You can get a high mileage E46 M3 for about $2k more than a high mileage 330 ZHP. If anyone buys an M car thinking you should get 200k+ miles out of it as the norm...they are mistaken. The only M car that has kind of gotten close to that is the E36 M3 which really didn't have an M engine in it.

[XMetal]

Hey everyone. It appears that Andrew Lang is having trouble activating his account on here and has asked me to post the following for him. Please note that I am not, in anyway, associated with Lang Racing...just a recent happy customer.

Andrew Lang of Lang Racing:
Hi everyone, I just found this post and I guess I’m a little late at getting to this one. I have some thoughts I’d like to share on the S65 issues people are having and some of the information in this thread. I won’t comment on which oil should be used because I haven’t looked into it thoroughly enough. For those who are interested in rod bearing engineering and general design principles/failures associated with bearings this is a good read:

http://www.mae.ncsu.edu/eischen/cour...ringDesign.pdf and http://www.studebaker-info.org/tech/...CL77-3-402.pdf

Of particular interest is the section describing the rod bearing failure type “wiping” which is what is occurring in both the S54 and S65 (probably S85 as well).

I think Clevite explains this in the most easily digestible way:

DAMAGING ACTION

The absence of a sufficient oil film between the bearing and the journal permits metal-to-metal contact. The resulting wiping action causes premature bearing fatigue.

POSSIBLE CAUSES

1. Insufficient oil clearance – usually the result of utilizing a replacement bearing that has too great a wall thickness. In some cases, the journal may be oversize.

2. Broken or plugged oil passages, prohibiting proper oil flow.

3. A blocked oil suction screen or oil filter.

4. A malfunctioning oil pump or pressure relief valve.

5. Misassembling main bearings metering off an oil hole.

6. Lubrication system not primed before start up.

There are of course other causes that are more permanent in nature and would have more to do with the design of the engine. On the S65 there’s some reasons why BMW might have chosen that tight rod bearing tolerance, as others have mentioned, increased efficiency and power. The task of designing a high output engine that will be reliable for a long period of time without the ability to test it under a variety of environmental conditions is hard. We are quick to point fingers at what seems like a very obvious design flaw to us, now that we have thousands of engines in the hands of the public to tear apart and inspect. Having this data available to us makes it easier to determine the cause of the failures. In the case of the S65 the oil film thickness is a problem just as it was in the S54. Of course there are many reasons this could be occurring, whether it’s any of the reasons Clevite listed above or a more serious design flaw like insufficient rod bearing clearance. In the case of the S54 we felt it was safe to say the cause of the rod bearing failures was a permanent condition based on the design of the motor, whether that be the oil pump volume/pressure, the rod bearing width/diameter, or any of the other factors that bear on oil film integrity.

With the S54 my main purpose for creating a kit with a wider rod bearing was to increase the surface area of the rod bearing and therefore increase its load carrying capacity. For more information on this you can purchase this paper: http://papers.sae.org/470203/ . To me and my team this was the most definite way to cure the issue with the S54 rod bearing. We continuously found (as others have found) the top rod bearing wearing through on many of the engines we disassembled. Of course this could be oiling issues or oil starvation and could be the fault of the owners of the car as well as the design of the oil system.

That being said I never claimed that the S65 rod issues should be addressed in this way. However, from what I read here a similar solution should be considered especially for those individuals who have a damaged crankshaft. Once bearings are spun the crank has to be ground or thrown out. If you are considering an engine build at the time it might make sense to also upgrade the rods and pistons. If you are going down that road it can be economical to choose a rod from a different engine that has a smaller diameter and a wider journal to both allow you to save your damaged crankshaft while also increasing load carrying capacity of the rod journal. We also have the option of using non-BMW rod bearings which can save the customer money and still be an upgrade in quality from the stock bearing.

Our experience building stroker racing engines has allowed us to have a close relationship with the local crankshaft manufacturers in southern California. We maintain some very tight tolerances, .00005” journal diameter tolerance has not been a problem. We always heat treat and nitride our crankshafts and rebalance them after any work is done. In the case of the S54 we even take extra steps with the blocks we use and have the block line honed or line bored and install ARP main studs. Taking this one step further we will be working on designing our own billet steel main caps and doweling them to the block to reduce crankshaft movement. This concept might be similarly applied to the S65 and S85 to help with reliability especially on higher output engine builds.

There are other very high level engine assemblers and designers in my local area and I’ve seen the work they do, it’s exceptional. Fortunately for me and my customers we happen to utilize a lot of the same resources.

To address those concerns about my teams’ ability to work on the S65 I will say that the only reason that we don’t have more experience with these motors is because they are too expensive to race and my customers aren’t willing to spend the money to fully build them. I’d be happy to build an S65 or S85 stroker motor for a race engine but I myself could never afford to campaign it, neither could most of my current customers.

Someone mentioned an S65 stroker crank cost and I think it was double what my retail price would be on that crankshaft. My retail price is 4000 USD for that crankshaft, I am willing to subject my crankshaft any testing/inspection our customer might want but we know the quality of our cranks are on par with the cranks from VAC and Dinan. Similarly the S85 is 4500.

It sounds like a lot of people will end up needing to remove their crankshaft and at that point the strokers become viable options especially if there has been damage to any rods or pistons. BMW pistons and rods cost significantly more than aftermarket rods and aftermarket pieces tend to be higher quality and lower price and weigh less. We have experience taking BMW blocks and inserting completely custom internals into them, we have our components made with the clearance that we desire and measure every single component before assembling it to make sure our machinists aren’t dropping the ball. There is no plastigauge in my assembly room. For engines that are as expensive to replace as the S65/85 you would want at least this level of assembly work to be done on it.

For those looking for economical options and actually resolving the issue the crankshaft regrind service is also something we can take care of just as we do on the S54. You could even specify your own wild requirements as some customers have been doing with the S54. Offset grinds with smaller diameter to increase stroke on the stock crank, wider bearing journals, and of course, appropriate bearing clearance. There are many options it just depends on how much engineering you want to do and how much you want to let us do for you.

Hopefully this information helps someone a little bit. I rarely have the time to come check out the forums but I invite anyone who has questions to give me a call anytime or shoot me an e-mail.

[Wendall]

I will be visiting Lang Racing today. I will report back.

[W///]

Wow, just noticed some responses are magically disappearing.

[Wendall]

So, I just went to Lang Racing to talk with Andrew Lang and Calvin. Lang Racing is a highly legit shop. They are a full on race shop. I spoke to Andrew about S54, S65 and S85 engines and each engines specific problems. Andrew was very knowledgeable and showed me several engines that were being rebuilt due to thrown rods.

I have not seen another BMW/Porsche shop with as many engine builds going on. He told me that he is primarily an engine builder and he like to make his own products instead of reselling others. Andrew and Calvin were really cool and I loved the shop.

The shop had one race E30 M3, an older 944 porsche that was being race built, a 964 Porsche with a 3.8l stroker and a few E46s and e36s. These guys are serious mechanics. The shop was loaded with engines, diffs, transmissions, and prototype carbon fiber parts (brake cooling kits, and aeroparts).

Andrew normally targets the really race/track fanatics but they are also increasing there services to forum enthusiasts.

Andrew is gonna do some more research and will try to find a better and more permanent solution to our S65 rod bearing issues. He is gonna try to get custom made clevite bearings mass made to help the S65 community.

[gatorfast]

Originally Posted by W///

Wow, just noticed some responses are magically disappearing.

Yea whats up with that

[thekurgan]

DAMAGING ACTION

The absence of a sufficient oil film between the bearing and the journal permits metal-to-metal contact. The resulting wiping action causes premature bearing fatigue.

POSSIBLE CAUSES

1. Insufficient oil clearance – usually the result of utilizing a replacement bearing that has too great a wall thickness. In some cases, the journal may be oversize.

2. Broken or plugged oil passages, prohibiting proper oil flow.
3. A blocked oil suction screen or oil filter.
4. A malfunctioning oil pump or pressure relief valve.
5. Misassembling main bearings metering off an oil hole.
6. Lubrication system not primed before start up.


if #1 is the S65 issue, we may need a thinner oil, yet with a high sheer index in the interim. Nice work looking into different/better bearings.

[regular guy]

Sounds like Lang is using the same crank and machine shops I've previously mentioned. Nice of them to offer help.

Last week, I measured multiple cranks, rods, bearings, coated bearings, and treated bearings. I think we found a very viable bearing replacement that will add about 25% more clearance without grinding the crank. More details to come when I crunch all the numbers and get all the photos ready.

[regular guy]

Originally Posted by thekurgan

DAMAGING ACTION

The absence of a sufficient oil film between the bearing and the journal permits metal-to-metal contact. The resulting wiping action causes premature bearing fatigue.

POSSIBLE CAUSES

1. Insufficient oil clearance – usually the result of utilizing a replacement bearing that has too great a wall thickness. In some cases, the journal may be oversize.

2. Broken or plugged oil passages, prohibiting proper oil flow.
3. A blocked oil suction screen or oil filter.
4. A malfunctioning oil pump or pressure relief valve.
5. Misassembling main bearings metering off an oil hole.
6. Lubrication system not primed before start up.


if #1 is the S65 issue, we may need a thinner oil, yet with a high sheer index in the interim. Nice work looking into different/better bearings.

I had previously posted the same quotes, along with photos, and download links to the same Clevite white paper on bearing failures. I'll see if I can dig up the links and photos and bring them here as well.

[e92zero]

Originally Posted by regular guy

Sounds like Lang is using the same crank and machine shops I've previously mentioned. Nice of them to offer help.

Last week, I measured multiple cranks, rods, bearings, coated bearings, and treated bearings. I think we found a very viable bearing replacement that will add about 25% more clearance without grinding the crank. More details to come when I crunch all the numbers and get all the photos ready.

Cool! Can't wait. A bit premature but if we do get the extra 25% clearance, should we still goto 0-40 or we can stick with the tws?

[Wendall]

Originally Posted by regular guy

Sounds like Lang is using the same crank and machine shops I've previously mentioned. Nice of them to offer help.

Last week, I measured multiple cranks, rods, bearings, coated bearings, and treated bearings. I think we found a very viable bearing replacement that will add about 25% more clearance without grinding the crank. More details to come when I crunch all the numbers and get all the photos ready.

Regularguy, much appreciated for all the contributions. Please publish your results when available.

One other thing, I told Lang Racing about the blue upper bearing and red lower bearing and told him that we can possible increase clearance by using two red bearings. He said that would be a great and cheap solution. However, he said he needed to make sure the materials hardness is the same on both blue and red bearings. He mentioned that bmw has used harder metals in the upper bearing since it has more contact with the journal due to movement of the crank.

[thekurgan]

Originally Posted by regular guy

I had previously posted the same quotes, along with photos, and download links to the same Clevite white paper on bearing failures. I'll see if I can dig up the links and photos and bring them here as well.

You're the man, thanks for taking the time.

[regular guy]

Originally Posted by biggynuts01

Regularguy, much appreciated for all the contributions. Please publish your results when available.

One other thing, I told Lang Racing about the blue upper bearing and red lower bearing and told him that we can possible increase clearance by using two red bearings. He said that would be a great and cheap solution. However, he said he needed to make sure the materials hardness is the same on both blue and red bearings. He mentioned that bmw has used harder metals in the upper bearing since it has more contact with the journal due to movement of the crank.

Yes, thank you. We're already on top of that and getting some bearings to kawasaki00 for analysis. The proposal won't use two red shells. Just give me a day or two to pull it all together please.

[Wendall]

Originally Posted by regular guy

Yes, thank you. We're already on top of that and getting some bearings to kawasaki00 for analysis. The proposal won't use two red shells. Just give me a day or two to pull it all together please.

you da man!

[L4ces]

Good job guys and good luck, hopefully you'll find a solution for us.

I wonder if the extra clearance equates to less efficiency and less horsepower.

Some folks have suggested that the tight tolerances were the effort to increase efficiency and horsepower.

[kawasaki00]

Originally Posted by L4ces

Good job guys and good luck, hopefully you'll find a solution for us.

I wonder if the extra clearance equates to less efficiency and less horsepower.

Some folks have suggested that the tight tolerances were the effort to increase efficiency and horsepower.

These are folks that don't know what they are talking about.
Tighter clearance does not make more power.

[L4ces]

Originally Posted by kawasaki00

These are folks that don't know what they are talking about.
Tighter clearance does not make more power.

There should have a question mark, but I didn't tell Siri to put one there.

This is what I was referring to

"On the S65 there’s some reasons why BMW might have chosen that tight rod bearing tolerance, as others have mentioned, increased efficiency and power."

Thanks for addressing that kawasaki00.

[kawasaki00]

Originally Posted by L4ces

There should have a question mark, but I didn't tell Siri to put one there.

This is what I was referring to

"On the S65 there’s some reasons why BMW might have chosen that tight rod bearing tolerance, as others have mentioned, increased efficiency and power."

Thanks for addressing that kawasaki00.

O Yea, sorry I wasn't directing that towards you. What I meant was those who write the articles that state that really don't have a true world experience on how the stuff works.

[L4ces]

Originally Posted by kawasaki00

O Yea, sorry I wasn't directing that towards you. What I meant was those who write the articles that state that really don't have a true world experience on how the stuff works.

I figured that after re-reading.
Again, thanks for all this work so far fellah's.

Carry on.

[LangRacingDevelopment]

Originally Posted by kawasaki00

These are folks that don't know what they are talking about.
Tighter clearance does not make more power.

I was finally able to get access to actually write a post here on my own. I'll try to explain what I said and why I think it could have a bearing on the S65 engine which, I admit, have not had a chance to build.

It's been said numerous times here that the traditional rod bearing clearance rule is something like .0007" to .001" per inch of bearing diameter. In many performance applications an even looser bearing can be specified and a higher viscosity oil used. Many professional level race engines use extremely tight clearances on rod bearings. Running tight clearances of course requires tight tolerances, tight tolerances increase cost, but in racing cost is usually an afterthought. When all journals are perfectly round, true and have a perfect finish and rod bearings are precision fit a builder can use extremely tight clearances.

Why do this? A smaller bearing clearance will reduce the volume of oil required to fill the space between the journal and the bearing and maintain the oil film. This is a good thing if the oil viscosity is thin enough to to flow well into that tight area. This also means the oil pressure doesn't need to be as high so the load on the oil pump will be less. A tighter bearing clearance allowing the engine to use low viscosity oil also decreases windage losses at high RPM, once again, helping with horsepower. Tight bearing clearance also distributes load over wider bearing surface area for a more uniform distribution of the combustion pressure.

The reality of engines today is that as we advance the sophistication of our machinery we are able to build close tolerance engine components at an ever reducing cost. This is desirable to the production engine manufacturer because they can use a lighter oil, increase MPG and horsepower and sell more cars.

Most NASCAR engines for example will run .001" rod and main bearing clearance on engines that are ~1.85" and 2". They use extremely thin oil like 0W-30 with ZDDP/Phosphorous content. ZDDP obviously isn't great for street cars with cats but most race oils are packed with these additives. In the engines we build we like to recommend the Liqui Moly MoS2 additive for the same reason.

Back to BMW, I'm not sure what the main bearing clearances are but if they are tight I would suspect BMW was trying to increase fuel economy and maybe save from having to drive the oil pressure so high, efficiency and power go hand in hand.

That being said, I wouldn't build a race engine with tight tolerances unless there was no other way to make power, rules etc. It makes much more sense to me to use higher viscosity oil and wider bearing clearances. This gives room for machinist mistakes as well as the distortions that occur at high RPM/load.

I would think it odd for BMW to spec 10-60 oil and then intentionally use extremely tight clearances. If simply using low viscosity oil solved any issues that would be convenient. However I think its dangerous to jump to the conclusion that a thinner weight oil will solve all problems without knowing the complete design of the rest of the engine. I don't know everything about the S65, I admit that, but before I made any assumption about how to permanently resolve this issue (if it is that serious) it seems like one should assemble and understand the entire engine to make sure that their rod bearing fix doesn't have detrimental effects on other engine components.

It would be interesting to install one of our race car dataloggers into an E90 M3 and send it out on track and take a look at the data on oil pressure. In our race engines we've always been able to pinpoint trouble areas that you wouldn't expect to see. For example we found a problem in our oil pickup system under heavy sustained breaking when our engine was a quart low on oil. That's the kind of data you would want to have to determine whether the S65 starves of oil at any point. I realize we are talking about "freeway" motors here so maybe this isn't relevant.

Regardless, it seems to me that there are a good number of other factors involved in this situation that seem to be ignored. I personally wouldn't be satisfied with installing a bearing with .002" clearance and calling the problem resolved.

[regular guy]

Originally Posted by LangRacingDevelopment

Back to BMW, I'm not sure what the main bearing clearances are but if they are tight I would suspect BMW was trying to increase fuel economy and maybe save from having to drive the oil pressure so high, efficiency and power go hand in hand.

Here you go: main and rod journal / clearance specs as best as we can get them measured from two cranks / rods in 2011, an another two cranks / rods in 2013.

http://www.m3post.com/forums/showthread.php?t=892838