What is the crankcase vacuum in the PCV System on these V10's at Hot/Idle?

More chains than brains. only stirring people.

Mechanics Vs Engineers. The Age old battle. If only mechanics designed engines and such... Maybe mechanics wouldnt need to fix the engineers snafus'?

Thanks for contributing you time and knowledge on the subject, please keep the community updated on possible solutions, it seems like such a shame for one of the most exciting M engines to be such a risky ownership proposition, I hope the collective knowledge of folks like yourself can solve this so we can enjoy these vehicles for years to come, it does seem unusual that some examples make it more 300,000kms while some die at 50,000 I would so like to know why?

Why not just develop a softer tensioner?

My armchair engineer after a mid strength beer thinks that BMW should have made the crank sprockets index on to a single forging vs. the let's just bolt this on here and hope for the best. I'm also of the opinion that behind the crank pulley should have had another main bearing to support the snout of the crank from being pulled up.

Yep, still love my 2013 E92 - 335IS.. :Lemans blue, DCT, one of 269 (and now brembos, Konis, an LSD, Delrin Arms and Rods and //M parts up front) - and no S motor heartache. Just N54 leaks.. and only 80K miles.

THANK YOU SO MUCH FOR THIS VIDEO. Way too many times do I see people thinking they are fine just doing rod bearing replacement on their S65 thinking they are fine. NOPE! If you want true piece of mind you need a FULL ENGINE TEARDOWN down to the crankshaft. Btw, Interesting repair for this issue.

Like most new bmw equipment its built to last until the warranty runs out then they have no comebacks.

This is beautiful. This is what I need

Another solution would be to throw an s85 in there. If you could get the dct to work with in on the stock tcu would be bonus points

Niño Cabezón Games gameplay e60 m5 v10

"Tight clearance engine" isn't a thing. Right clearance engine is. There's engines that are higher strung than this that last longer. Examples are easy to find in all types of road going and motorsport vehicles. It's a design issue. Nice car, nice engine when it runs, great engine after you guys re-work it. Thought the fact that it even requires re-work tells you that it has a design flaw.

We should neutralize that excessive upward force by adding another force downwards. Something in the crank pulley, I don't know, just thinking loud. Zero engine inside work.

Very good video thank you, like you said not much info on this on the web. I am a lucky winner of a main bearing failure also. BMW should be responsible for this, the B7 RS4 is also a high revving motor but does not have this issue, very upset with BMW about this

How many engine would be ok if just people change there oil in high rpm sports cars … like 3000 miles then change oil.. this nonsense with 15000-20000 miles interval longlife bla bla . Its just for the car maker to sell cars with a TCO of service that will look ok. But in high rpm v8 oil need to be change more often then people does

Have you experimented with WPC treatment on both main and con-rod bearings when rebuilding?

Germans never learned how to engineer engines properly. 😂

how much does it cost to put in new main bearings?

can the main bearings be replaced while the engine is still in the car?

amazing work sir's!

The higher redline these S65 are able to achieve likely means you have stiff valve springs and requires more force to turn hence the need for a double row chain, heavy duty tensioner, sprockets, etc. I assume during testing, there wasn't any issues found with this setup. But after hundreds of cycles of running the engine on and off, the oil isn't able to prevent contact. Could be a very brief period of lack of lubrication such as replacement of an oil cooler. I'm surprised to learn you're running an extra thousand in clearance. I would have gone for half a thousand only.

Is there any indicator what Mileage these start to fail? I just purchased a clean e92 M3 from Sydney with 115k kms on the clock now. RB done earlier this year

You hit the nail on the head. Lots of the builders over here in US/UK/EU have already identified and confirmed your thoughts on the double row chain being the issue causing the #1 failure. Your idea of a custom set for main bearing replacement is great, hopefully some of the suppliers can start supplying custom sets with a larger #1. Mahle Motorsport in the UK for example.

This is all fine and dandy but do we know the oil change history of these s65’s?

Good old fashioned hot rodding can do right here. If this is a catastrophic design flaw soon the world is going to be running short of these blocks.

Do you notice a difference in number of failures between the early AC/PS belt drive arrangement and the later one?

What is the cost of replacing the main bearings? The whole engine has to come out?

Lost torque?

Reasons why BMW chose a chain over a belt on these engines, the M10, and M30 have more oil clearance, not sure about M88-M90 oil clearances but stands to reason they have more than these S65 engines . Early M10 and M30 engines are double row chains, they later when with single row chains. It’s quite amazing that the tension on them causes crank to bend at high rpm. There an old hot rodders trick that was used on the SOCH V8 Ford engines, apparently the timing chains would stretch enough at high rpm that one bank on the engine would cause the cam timing to change, Ed Pink described the trick in detail about how he discovered the issue and corrected it for high rpm use in nitro methane drag cars. Two totally different things but somewhat related.

Awesome stuff mates, cheers from USA

What is your opinion on running a thinner oil in the S65 like a 5W40? I suspect its better because the tight clearance but would it maybe also have a effect on the chain tensioners?

Why does the S85 only use two simplex timing chains compared to 2X duplex chains on the S65?

Surely, increasing the bearing clearance in No. 1 main bearing means the crank can bend more? Will the crank fail more prematurely due to cyclical bending stresses? And opening up the oil port; if you increase the flow to No. 1, then there is less for No’s 2-5? Might not make a difference, but it’s a ballsy move if you’re not certain that you need the extra oil on No. 1.

What do you have there is complete disregard to correct oil change intervals

Is this main bearing issue the same in the S63 V8 in the F10 M5?

Common problem is the tw*ts ouy of uni that dont undersand life and think itc all cad happy n easy but dont realise ya need to actualy moddle it

There's one thing i tell all my customers: if you want a BMW just get an inline six one. N/A or turbocharged whatever but stay away from all the V-type engines they produced especially if you want to go fast on track. Always kept me out of trouble like the ones you adress here. Greetings from near the lovely Nordschleife very nice of you to adress this topic.

wear happening on start up. edit: do these cars have start stop? cranks dont touch bearings if there is oil, thats my little rule

I saw this when M359 restorations was rebuilding his S65 engine and thought to myself "Oh oh, this is gonna be a HUGE problem!" The biggest problem with this is that this is a whole engine rebuild and with the trouble M359 had to go through before he found a reputable shop, there are about to be a whole lot off blown up e92 m3 engines...

Placing an ls engine in a bmw is a great way to lower its market value.

This may be a newbie question but Is there consideration for the thermal expansion of the steel insert on the aluminum block?

To say that a road engine that requires maintenance rebuilds isn't flawed is very generous.

Why dont you measure home much tension is applied from the chains and calculate additional radial load from chain at speed. That main bearing does not have a lot of surface area. Opening up the clearance will make wear worse for the lower side. Is the front bearing wear from high rpm, or low rpm with cold oil running additional heavy loads through ac and alternator. That chain oil squirter is most likely reducing flow to the bearing also.

BMW m crankshafts normally have almost an extra 0.001” of clearance in the main no.1 Journal anyways, however I always make sure no1 is the loosest when sorting bearings into size order. 👍

Only cause is 10W60 oil.

How about increasing the oil pressure..flow? This spun bearings can also lead to crankshaft snapping

Throttle actuators, rod bears, main bearings, vanos, the oil spec 10W60, seems quite a lot for a road going engine to manage. The S54, S65, & S85 were the last of the NA M engines. Mindset needs to be, service like a race engine...

This is old news lol

One of the reasons why i replaced my e92 competition with a m336 limo