5W-50 Recommended by TroyJeup

Most of these cars got the BMW 4 year free servicing with BMW’s specified 1 year or 15,000 mile changes, for the first 4 years of their life. A small percentage of owners may have paid for additional oil changes. Out of warranty and/or in the hands of new owners, probably a larger percentage of owners changed the oil at shorter intervals.

Do you think BMW damaged these cars with its specified OCI?

330indy wrote

Scharbag wrote

Frozen wrote

A Honda with a V8 that revs up to 8400 RPM?

F20C revs to 9000 RPM. 500ml per piston, same as the S65. Here is the bore and stroke:

F20C Bore = 87mm
F20C Stroke = 84mm
Mean piston speed = 25.2 m/s at 9000RPM

S65 Bore = 92mm
S65 Stroke = 75.2mm
Mean piston speed = 21 m/s at 8400RPM

The number of pistons has very little to do with rod bearing dynamics. They either work properly or they do not. I think the S65 is a wonderful engine. I own one. But BMW did not properly design the bottom end of the engine. Nor did they employ assembly techniques that ensure minimum tolerances are maintained.

This is not my opinion. This is the opinion of a group of professional engine builders. They have a very detailed thread on the subject that is full of good data that shows engine building best practices were not used by BMW. Physics is physics, regardless if it is built by the Germans.

Cheers,

OK perhaps you already have shared but please do again : your S65 OCI regimen /details

Not really sure what my OCI has to do with it but:

I change oil every year at a minimum as I do not always drive it that much. Now that I can drive it all year, I will change the oil yearly or every 8000km. I fully realize this is more often than needed with modern synthetics but oil is cheap and I do it myself.

I use the BMW oil and Mahle filter included in the FCP kit. If they offered 5w50 Redline, I would use that as I have before and it is good oil. EDIT: FCP sells Redline... Perhaps I will start using it.

I run BE bearings and BE ARP hardware. My factory 088/089 bearings looked good for an S65 but still showed wear, which is unacceptable for any engine at 30,000 km.

Regardless, no amount of new oil can fix overly tight bearings. It may slightly prolong the inevitable, but it will not prevent it.

330indy wrote

😂

You got me...

Scharbag wrote

330indy wrote

😂

You got me...

This was supposed to attach 😂😂😂 thanks for the sense of humor

330indy wrote

Scharbag wrote

330indy wrote

You got me...

This was supposed to attach thanks for the sense of humor

Sure... yup.

Perhaps we should all start using DuraLube too...

Scharbag wrote

Changing the oil every 1000 miles will not extend the life of an engine with improperly designed hydrodynamic bearings. If it is too tight, it is too tight. This not only applies to bearing to journal clearance, but also to rod side clearance. With the lack of quality control, shown by data collected by those who initially identified this issue, BMW built a bunch of really great engine with a statistical ticking time bomb.

Modern synthetics can run longer intervals. This is shown by oil analysis reports where people paid for TBN. Most people, myself included, change oil far sooner than actually required.

A quick review of Clevite's information discussing bearing failure modes will support the hypothesis that S65 and S85 bearing wear is indicative of oil starvation, not oil contamination. If viscosity were a major factor causing increased wear, everyone running 0W40 oil should be seeing much greater wear than users of 10W60. This seem to not be the case - or at least we have not seen a rash of 0W40 oil users with worn or spun bearings.

FYI:
Castrol 10W60 V@40C = 160
Castrol 10W60 V@100C = 22.7
Castrol 10W60 HTHS = 5.2

Mobil 1 0W40 V@40C = 70.8
Mobil 1 0W40 V@100C = 12.9
Mobil 1 0W40 HTHS = 3.6

Redline 5W50 V@40C = 130
Redline 5W50 V@100C = 21
Redline 5w50 HTHS = 5.0

Happy motoring.

Never said it would have. Only that engineers were not involved in final decision of the OCI.

CarPoor wrote

Never said it would have. Only that engineers were not involved in final decision of the OCI.

You are missing the point. Extended OCIs will not damage the bottom end of a well designed engine. Modern synthetics are very stout.

The S65 engine has an issue with lack of clearance due to poor design and manufacturing tolerances.

If you have data that supports another conclusion, please share.

Cheers,

CarPoor wrote

Never said it would have. Only that engineers were not involved in final decision of the OCI.

Do you know that to be a fact? If accountants were involved, don’t you think they would be getting approval from the engineers as to what the engine needs? For example, do you think accountants decided the engine needed 10W60? Did accountants set the valve adjustment interval for the solid lifter S54? Given BMW warranties the cars for 4 years, I think engineers must have been consulted as to the maintenance schedule. I doubt the accounting department is coming up with random maintenance schedules purely based on minimizing upfront service costs without any input from the engineers that put together the drivetrain and tested it and actually know or should know what it needs for maintenance.

Doubtful the 5w50 was the reason that particular S85 made it to 215k.

There are more than a few S65s on the forum past 200k miles that have run 10w60 the entire time. So even with a small sample size that should debunk the notion it was due to the oil....not to mention it's all we have.

The bearings have a design flaw and changing the oil weight isn't going to help.

A properly designed motor should not have any RB issues. Ferrari has been making 8500rpm motors for multiple model generations and those things aren't throwing rods left and right.

It's still the german lottery out there if you haven't replaced them. Very few reports of aftermarket bearings failing, not counting installation/mechanic errors.

pbonsalb wrote

Do you know that to be a fact? If accountants were involved, don’t you think they would be getting approval from the engineers as to what the engine needs? For example, do you think accountants decided the engine needed 10W60? Did accountants set the valve adjustment interval for the solid lifter S54? Given BMW warranties the cars for 4 years, I think engineers must have been consulted as to the maintenance schedule. I doubt the accounting department is coming up with random maintenance schedules purely based on minimizing upfront service costs without any input from the engineers that put together the drivetrain and tested it and actually know or should know what it needs for maintenance.

In BMWs specific case, no. In general automotive and mechanical, yes. I make these calls on occasion as do my colleagues in other sectors including automotive who are our customers. If engineering does not have a forcefully compelling argument and we and or marketing want to provide “free” maintenance or sell the customer on reduced running costs we will make said adjustment to the end user warranty maintenance requirements. This of course tempered with acceptable risk that some units may have significant failures under or just outside the warranty period. Finance/accounting may make the call without marketing’s input if we are attempting to preserve profit margin or recover profit margin that is often sacrificed in the engineering phase.

Scharbag wrote

You are missing the point. Extended OCIs will not damage the bottom end of a well designed engine. Modern synthetics are very stout.

The S65 engine has an issue with lack of clearance due to poor design and manufacturing tolerances.

If you have data that supports another conclusion, please share.

Cheers,

No, you missed my point countering another users argument.

CarPoor wrote

If engineering does not have a forcefully compelling argument and we and or marketing want to provide “free” maintenance or sell the customer on reduced running costs we will make said adjustment to the end user warranty maintenance requirements.

So BMW’s engineers would be consulted, and in this case had no forcefully compelling argument against 15,000 mile or 1 year oil changes. In other words, BMW’s engineers were consulted.

CarPoor wrote

In BMWs specific case, no. In general automotive and mechanical, yes. I make these calls on occasion as do my colleagues in other sectors including automotive who are our customers. If engineering does not have a forcefully compelling argument and we and or marketing want to provide “free” maintenance or sell the customer on reduced running costs we will make said adjustment to the end user warranty maintenance requirements. This of course tempered with acceptable risk that some units may have significant failures under or just outside the warranty period. Finance/accounting may make the call without marketing’s input if we are attempting to preserve profit margin or recover profit margin that is often sacrificed in the engineering phase.

Hi! Automotive engineer here. Engineers were 100% consulted on this OCI and signed off on it.

For the doubters. Do any of you here deny that TroyJeup has probably built more S65/s85 engines than just about anyone on the planet?

If you don't deny that then he has credibility.

I'm not saying Redline 5w30 solves the rod bearing issues these engines have because it's a complex issue, but does it help? Not even a 1% chance it helps? Is this really your stance? Totally disregard the recommendation by a master engine builder?

Go look at his Instagram for starters. The guy practices what he preaches.

Many of you are dismissing this guy as if he's an idiot for even considering that the oil weight might help especially for those of us with these engines in colder climates.

Even if it offers a 1% improvement on bearing wear why wouldn't you do it?

lol

ok histrionics aside, we don’t have any proof of anything and neither does troy without doing some pretty expensive control studies. It’s not as simple as anecdotes and even a few hundred engine builds and tear downs barely qualifies as better than an anecdote

However - informed guesses are often The Best an Engineer Can Get (tm) But we have enough of these anecdotes to make informed decisions and enough of us who have held good long running race engine bearings in our hands know BMW shat the bed on this part of the S65/85 design. We also have the rare advantage of somebody doing some pretty significant reverse engineering and data gathering to offer an aftermarket part in a high risk area to be playing around in, and lots of people getting good results from them (BE)

You don’t know for sure pokeberry pie is going to kill you, but you know not to eat pokeberries, even if nobody has done a control study to determine the lethality of pokeberry pie

I don't think anyone here doubts Troy has built more S85s than anyone else.

I think what some of us are trying to say is that oil weights have not proven to solve the problem. A few motors running a slightly thinner oil is not enough. That particular motor was just luckier than the rest.

Nobody here has pulled a set of factory bearings that looked reasonable for any given mileage.

For the few that have pulled a second set of aftermarket bearings, they showed no wear.

Clearance issue, not oil.

And how do we measure a 1% improvement? Not sure it's calculable.

Frozen wrote

For the doubters. Do any of you here deny that TroyJeup has probably built more S65/s85 engines than just about anyone on the planet?

If you don't deny that then he has credibility.

I'm not saying Redline 5w30 solves the rod bearing issues these engines have because it's a complex issue, but does it help? Not even a 1% chance it helps? Is this really your stance? Totally disregard the recommendation by a master engine builder?

Go look at his Instagram for starters. The guy practices what he preaches.

Many of you are dismissing this guy as if he's an idiot for even considering that the oil weight might help especially for those of us with these engines in colder climates.

Even if it offers a 1% improvement on bearing wear why wouldn't you do it?

Technically, Dingolfing has built the most S85s and Munich has built the most S65s. We have seen how that worked out...

I do not know Troy. I am sure he is a good engine builder or people would not use him. If you asked Troy to build you a high revving engine with 0.00029"/" bearing clearance and told him you intended to use 10W60 oil, I bet you he would tell you to get bent. Unfortunately, with the parts BE had access to, they were able to creat a situation with exactly that clearance ratio in an S65.

From BE: "That's already dangerously too small and almost half the Clevite recommended clearance. So let's look at what happens when we put all of the parts together at their maximum stack up (for minimum oil clearance). Keep in mind each of these parts is within it's allowed tolerance limit and would pass inspection. But look what happens when you put them all together.

Rod bore: 2.20470
Bearing thickness: 0.07865
Connectring rod journal: 2.0468
Clearance calculation: 2.2047 - (2 * 0.07865) - 2.0468
= 2.2047 - 0.1573 - 2.0468
= 0.00060 inch clearance"

Here is some information from bearing suppliers:

King: "The optimal range of clearance is 0.0015-0.003” (for a bearing with 2” diameter). Looser clearances are more suitable for highly loaded engines working at high rotation speeds and with thicker oils. Tighter clearances provide a better combination of hydrodynamic parameters in less loaded engines working at lower rotation speeds and using thinner oils."

Summary: engine should have between 0.00075"/" and 0.0015"/" bearing clearance.

Clevite: "For most applications .00075 to .0010” (three quarters to one thousandth of an inch) of clearance per inch of shaft diameter is a reasonable starting point. For example, a 2.000” shaft diameter would require .0015 to .0020” bearing clearance (.00075 X 2.000” = .0015” and .0010 X 2.000” = .0020”). Using this formula will provide a safe starting point for most applications. For High Performance engines it is recommended that .0005” be added to the maximum value determined by the above calculation. The recommendation for our 2.000” shaft would be .0025” of clearance."

Summary: 0.00075"/" to 0.001"/" is a good starting point and that high performance engines should get an extra 0.0005".

ACL: "Vertical oil clearances should be approximately 0.025mm (0.001”) per 25mm (1”) of shaft diameter, plus an additional 0.013mm (0.0005”) for high performance applications."

Nominally, the S65 has a 0.00073"/" bearing clearance, below the bare minimum recommended by King, ACL and Clevite for any engine. If the three main bearing suppliers on the planet all say a minimum of 0.00075"/" is required, and 2 of them specifically state that high performance engines should get another 0.0005" of clearance, I have to question the validity of BMW's design decisions.

The point is: unless a hydrodynamic bearing is properly designed, nothing, not even unicorn tears, will eliminate the fundamental problem(s). Sure, better oil may prolong the useful life, but the problem still exists. Proper weight oil may also prolong the useful life. But the problem still exists. Reducing OCI may extend the useful life. But the problem still exists.

If, however, you can remove the problem by replacing a component, why not do that? This is like removing the knife before stitching the wound. Sure, stitches will stop the bleeding, but it has to suck to have a knife sticking out of you all day. And, at some point, you are going to start bleeding again.

Cheers,

Richbot wrote

lots of people getting good results from them (BE)

I have seen posts of only a few sets of BE bearings removed after some miles. Definitely not enough to draw any conclusions about good results. Hopefully over the next few years, people will change bearings a second time and there will be a number of examples of no wear after 50k or more miles. This can be said of any brand bearing replacement, not just BE; we just don’t have much in the way of results yet.

pbonsalb wrote

I have seen posts of only a few sets of BE bearings removed after some miles. Definitely not enough to draw any conclusions about good results. Hopefully over the next few years, people will change bearings a second time and there will be a number of examples of no wear after 50k or more miles. This can be said of any brand bearing replacement, not just BE; we just don’t have much in the way of results yet.

I agree, but we do have raw data, including oil flow information.

As BE said, if you are lucky enough to have a loose engine from the factory, it will likely last. If you got a tight engine, it will likely blow up - and soon.

At least we now have a number of high quality options to build and engine with recommended rod bearing tolerances.

Cheers,

Ab28 wrote

Nobody here has pulled a set of factory bearings that looked reasonable for any given mileage.

That actually is not true. I have seen a few sets posted in the forum. It’s a small percentage, though. Probably 10% or less that look good.

pbonsalb wrote

That actually is not true. I have seen a few sets posted in the forum. It’s a small percentage, though. Probably 10% or less that look good.

Looked good or just less worn than others?

...I have seen sets that looked ok comparatively, but not outright.

I have seen some posted that I thought looked good, like what would be common on other motors.