Official S65 Rod Bearing Condition Example Thread

It is generally recognised that on startup (and shut down) is where the most bearing wear occurs on any engine, as there's no oil pressure initially (which is why cars that have stop/start tech tend to have harder bearings, as well as the EU banning lead bearings).

I think Swamp fox was originally pertaining to that, additionally we know that the S65 OEM bearing clearances are tight, adding to that problem.

Swamp Fox
Re sump heating, I guess it could work, but the only way to know would be to do it from the 1st day the 1st owner bought the car.
Similar issue with using say, 5w50 oil, it might well have worked if it was in the engine from day 1. But I doubt anyone has (except perhaps in this case, where people have replaced rod bearings with OEM ones along with using 5w/50, but I bet their aren't many people who have).

Hello guys.

Were there some accidents with engine breaks on BE bearings installed?

None that I know of, on the other hand, their were other failures which subsequently damaged the BE rod bearings, e.g mains failure

Assimilator1 wrote

It is generally recognised that on startup (and shut down) is where the most bearing wear occurs on any engine, as there's no oil pressure initially (which is why cars that have stop/start tech tend to have harder bearings, as well as the EU banning lead bearings).

While it may be true that most bearing "wear" occurs at startup, it is such a minimal amount that it is not worth talking about. There are many old vehicles out there that have good bearings in them that have been started thousands of times. The stresses on a hydrodynamic bearing sub 2K RPM with no load on the crank are miniscule. The oil film will adequately protect the crank just like it protects the camshafts - effectively becoming a lubricated bushing for 2 seconds until oil flow is restored.

As for harder bearings, they are never a good thing. Good old Pb/Cu Babbitt is superior. I am so thankful that my 2011 does not have that auto-start BS. What a useless feature. Especially on turbo cars - just what we want to do to a hot turbo...

RomanK wrote

Hello guys.

Were there some accidents with engine breaks on BE bearings installed?

One of the original DIY installs had a failure. It was thought it was due to an improper installation of the locating tang on a shell.

I'm sure there are other failures due to installation. There have been other failures due to main failure or other causes.

I do not believe any case has been tracked back to an actual failure of a BE shell being the root cause.

Scharbag wrote

While it may be true that most bearing "wear" occurs at startup, it is such a minimal amount that it is not worth talking about. There are many old vehicles out there that have good bearings in them that have been started thousands of times. The stresses on a hydrodynamic bearing sub 2K RPM with no load on the crank are miniscule. The oil film will adequately protect the crank just like it protects the camshafts - effectively becoming a lubricated bushing for 2 seconds until oil flow is restored.

As for harder bearings, they are never a good thing. Good old Pb/Cu Babbitt is superior. I am so thankful that my 2011 does not have that auto-start BS. What a useless feature. Especially on turbo cars - just what we want to do to a hot turbo...

Re start up, yep agreed, which is why most engines which are properly looked after can go well north of 200k miles. But start up (and shut down) is still where most of the wear occurs (on engines in general), small as it is.

Not a big fan of A.S.S myself, but I wouldn't call it completely useless, it does save some fuel, but at a cost of engine life, and it seems somewhat pointless on a performance car!
Re turbo'd cars, doesn't the ASS data parameters stop the engine shutting down if oil temperature is high??
(Hmm, I could check Suzuki's parameters for this, but even the turbo'd cars are barely high performance! lol)
Agreed about harder bearings btw, but that's what they had to resort to so that bearing life wasn't excessively compromised with ASS.

This was apparently the bearings at about 70k miles out of a very early model year 2011 car.

I just swapped rod bearings in my 08 E61 535xi with N54 motor at 157k miles and they looked way better than those in the photo above and better than those from my 08 E90 M3 with just 60k miles.

pbonsalb wrote

I just swapped rod bearings in my 08 E61 535xi with N54 motor at 157k miles and they looked way better than those in the photo above and better than those from my 08 E90 M3 with just 60k miles.

Photos???

Unfortunately the bearing are on my work bench in NH and I am now in FL.

Next time you're there we'd love to them (photo all if you can, could add to my tiny collection of good bearings!).

pbonsalb wrote

I just swapped rod bearings in my 08 E61 535xi with N54 motor at 157k miles and they looked way better than those in the photo above and better than those from my 08 E90 M3 with just 60k miles.

Just for fun during these times?

The rod bearings were preventative maintenance; the travel is something that had to be done, was not by choice, but we will try to work some vacation into it.

OEM bearings from a 2008 at 78k. While these bearings did not blow up the motor I won an even bigger lottery with a rod stripping during reassembly. Motor has to come out anyway, but at least the core is usable.

I think it would be incompetence if a rod stripped during reassembly, butI am just a DIYer who has done a few sets of rod bearings.

If stock rod bolts, my guess would be that an absent minded mechanic did a triple 70 degree on one bolt rather than two 70s on each bolt. If non TTY aftermarket bolts, I have no guess other than foolishly using an impact to install the bolts.

pbonsalb wrote

I think it would be incompetence if a rod stripped during reassembly, butI am just a DIYer who has done a few sets of rod bearings.

If stock rod bolts, my guess would be that an absent minded mechanic did a triple 70 degree on one bolt rather than two 70s on each bolt. If non TTY aftermarket bolts, I have no guess other than foolishly using an impact to install the bolts.

It has all of us puzzled. The shop is legit as is the tech. He was explaining that he used the OEM bolt in order to get a clearance reading. Old bolt was tightened according to the procedure which worked fine for the previous 7 rods. This was #8. Claim is the bolt yielded right around 20N-m so it never had a chance to be over torqued.
This implies a pre-existing condition, which is saying that rod cap remained perfectly in place for 78k without any strange bearing wear. With the new APR bolt the tech was able to grab just enough thread to torque it down to 50ft-lbs but I'm not about to start it up and roll that dice.
I'm curious if anyone has experienced a rod stripping or if anyone with spares to experiment with can try to force one to strip. It would be really good to know if retorquing the old OEM bolt using the BMW torque procedure could cause this .

GearKid wrote

It has all of us puzzled. The shop is legit as is the tech. He was explaining that he used the OEM bolt in order to get a clearance reading. Old bolt was tightened according to the procedure which worked fine for the previous 7 rods. This was #8. Claim is the bolt yielded right around 20N-m so it never had a chance to be over torqued.

Such a shame. What a bad luck case indeed. I'm shaking my head at the probability of what is alleged to have happened. It has been said (by who I can not recall) that failure is opportunity turned inside out. As frustrating (and potentially expensive) as the situation maybe, I encourage you to improve upon what has gone before. There are various scenarios one could pursue - depending upon one's financial wherewithal. One possible scenario is a "Stroker Kit". Here's a link below to a thread on the subject. From time to time, please keep us updated as to the situation and your progress with resolution. I sympathize with what it must be like to have to navigate your way through this event.

https://www.m3post.com/forums/showthread.php?t=1056559

DrFerry wrote

GearKid wrote

It has all of us puzzled. The shop is legit as is the tech. He was explaining that he used the OEM bolt in order to get a clearance reading. Old bolt was tightened according to the procedure which worked fine for the previous 7 rods. This was #8. Claim is the bolt yielded right around 20N-m so it never had a chance to be over torqued.

Such a shame. What a bad luck case indeed. I'm shaking my head at the probability of what is alleged to have happened. It has been said (by who I can not recall) that failure is opportunity turned inside out. As frustrating (and potentially expensive) as the situation maybe, I encourage you improve upon what has gone before. There are various scenarios one could pursue - depending upon one's financial wherewithal. One possible scenario is a "Stroker Kit". Here's a link below to a thread on the subject. From time to time, please keep us updated as to the situation and your progress with resolution. I sympathize with what it must be like to have to navigate your way through this event.

https://www.m3post.com/forums/showthread.php?t=1056559

Thanks! I'm with you on your perspective. The motor is still good, and in the case of a Dinan rebuild, is worth quite a bit. They are not too far from me, so I'm considering their 4.2L motor. My crank will need to pass inspection to pull this off. If for some reason it's toast then the 4.6L stroker will start to make more sense. Neither motors are cheap, $16k for the 4.2L and $24k for the 4.6L...add $8k or so if you need a motor "core". Still looking at options but these seem like a better deal than a new one from BMW. Would be good to hear what others have done or what options exist.

GearKid wrote

DrFerry wrote

GearKid wrote

It has all of us puzzled. The shop is legit as is the tech. He was explaining that he used the OEM bolt in order to get a clearance reading. Old bolt was tightened according to the procedure which worked fine for the previous 7 rods. This was #8. Claim is the bolt yielded right around 20N-m so it never had a chance to be over torqued.

Such a shame. What a bad luck case indeed. I'm shaking my head at the probability of what is alleged to have happened. It has been said (by who I can not recall) that failure is opportunity turned inside out. As frustrating (and potentially expensive) as the situation maybe, I encourage you improve upon what has gone before. There are various scenarios one could pursue - depending upon one's financial wherewithal. One possible scenario is a "Stroker Kit". Here's a link below to a thread on the subject. From time to time, please keep us updated as to the situation and your progress with resolution. I sympathize with what it must be like to have to navigate your way through this event.

https://www.m3post.com/forums/showthread.php?t=1056559

Thanks! I'm with you on your perspective. The motor is still good, and in the case of a Dinan rebuild, is worth quite a bit. They are not too far from me, so I'm considering their 4.2L motor. My crank will need to pass inspection to pull this off. If for some reason it's toast then the 4.6L stroker will start to make more sense. Neither motors are cheap, $16k for the 4.2L and $24k for the 4.6L...add $8k or so if you need a motor "core". Still looking at options but these seem like a better deal than a new one from BMW. Would be good to hear what others have done or what options exist.

There are some very knowledgeable people on this Forum who have made the switch to a stroker motor - in one form or another. SYT_Shadow made a Stroker motor thread. I suggest considering contacting him. Here's the thread link:

https://www.m3post.com/forums/showthread.php?t=1632771
.

GearKid wrote

Thanks! I'm with you on your perspective. The motor is still good, and in the case of a Dinan rebuild, is worth quite a bit. They are not too far from me, so I'm considering their 4.2L motor. My crank will need to pass inspection to pull this off. If for some reason it's toast then the 4.6L stroker will start to make more sense. Neither motors are cheap, $16k for the 4.2L and $24k for the 4.6L...add $8k or so if you need a motor "core". Still looking at options but these seem like a better deal than a new one from BMW. Would be good to hear what others have done or what options exist.

There are quite a few solution paths some of which are much more expensive than others. Lang Racing Development is at 22512 Aspan St. Lake Forest, CA 92630 and their 83mm stroker kit is sold by ECS Tuning for $8.8K. Lang Racing offers other various other S65 enhancements and rebuild choices. I just wanted to let you know about alternatives to Dinan. Not that there's anything wrong with Dinan (to quote Seinfeld).

Lang Racing 83mm stroke page:
https://store.langracing.com/83mm-stroker-kit-for-bmw-s65-engine-e90-e92-e93-m3/

If needed; Lang Racing Stroker Crank
https://store.langracing.com/bmw-s65-stroker-crankshaft/

Lang Racing Remanufactured S65
https://store.langracing.com/bmw-s65-engine-remanufactured-by-lang-racing-core-required/

ECS Tuning Stroker Kit (by Lang Racing)
https://www.ecstuning.com/b-lang-racing-parts/83mm-stroker-kit-for-bmw-s65-engine-e90-e92-e93-m3/s65-strk-kit~lng/

Car Bahn (Steve Dinan) 4.6L Kit
https://carbahnautoworks.com/product/s65-4-6l-stroked-and-bored-engine-kit-2/

See also KMS Racing Engines
https://www.kmsracingengines.com/bmw-v8-s65-565hp.html
.

GearKid wrote

It has all of us puzzled. The shop is legit as is the tech. He was explaining that he used the OEM bolt in order to get a clearance reading. Old bolt was tightened according to the procedure which worked fine for the previous 7 rods. This was #8. Claim is the bolt yielded right around 20N-m so it never had a chance to be over torqued.
This implies a pre-existing condition, which is saying that rod cap remained perfectly in place for 78k without any strange bearing wear. With the new APR bolt the tech was able to grab just enough thread to torque it down to 50ft-lbs but I'm not about to start it up and roll that dice.
I'm curious if anyone has experienced a rod stripping or if anyone with spares to experiment with can try to force one to strip. It would be really good to know if retorquing the old OEM bolt using the BMW torque procedure could cause this .

I wouldn't have thought it'd be a good idea to re-use an OEM bolt, they are stretch bolts, so once used I wouldn't think they'd yield anymore which could lead to over torquing?? Not a 100% on this though!
And, if he truly only did the 20 Nm stage then noway would that strip the threads. All very odd.

Btw, instead of buying a stroker motor (unless you really want to), how about buying a new rod and then having all the rods balanced? (still would need to strip it down of course).