Official S65 Bearing Specification/Clearance Wiki

[regular guy]

Originally Posted by swamp2

4 key observations for me, more or less repeating what they've said but also adding a bit of context:[LIST=1][*]So much for the expertise that told us absolutely no detonation here. However, to be fair, perhaps though that observation and conclusion was isolated to a very small subset of the total failures. I was pretty sure though that the conclusion was extrapolated across the entire scenario.

In all fairness, Kawasaki only saw one set of the bearings -- and they were NA, not supercharged. Furthermore, Clevite didn't identify which bearings "probably" showed signs of detonation. "Probably" isn't a very strong qualifier here. Certainly not enough for me to say "so much for the expertise."

I don't quite see how they are so certain that bearing clearance is not at all an issue. It seems pretty clear that just from fundamentals (the ones driving this thread from the beginning) that clearance and flow rate (or starvation) are related. Clearance and flow rate are directly related as viscosity and flow rate are inversely related.

I don't understand that either. I always thought they were related.

[regular guy]

Originally Posted by kawasaki00

Honestly, the top of that piston looks like crap, I have looked at some engines that were clean on the top and some that were like this. This engine is an example or how poorly some of the engines seal up. You could be correct but that engine is burning so much oil it is very hard to even know what is going on with it. I hate it is apart and a lost cause now but we have taken engines that have this trend, changed to a different oil and over time they clean up. The type/brand oil can make a difference too. I am not trying to side step your question it is just difficult to answer with the pieces we have.
Something else I wish I could have accomplished and I didnt have a block and pour plate with me and maybe RG could do it is repour the cylinder with these highly carboned pistons and see how much it raises compression. A few of the pistons had enough build up to effectively raise the piston height by about .002, this adds another tenth or two to the overall compression ratio and compounds the problem.
Furthermore I shoud have taken a side picture of that because it is hard to see how high the carbon was built up from the top view. There was alot for sure.

Wouldn't I need a fresh OE piston then repour after replacing this one?

I can take side pictures however. I may already have that. I will check and report back. Soonest would probably be Sunday.

[kawasaki00]

Originally Posted by regular guy

Wouldn't I need a fresh OE piston then repour after replacing this one?

I can take side pictures however. I may already have that. I will check and report back. Soonest would probably be Sunday.

You could pour it, then glass bead the top back clean and repour it.
To figure it accurately you need the gasket volume, bore size, dish cc, and cylinder head volume.

[MrStinky]

So isn't it clear BMW knew what they were doing now? Funny I don't see bmlvr around chiming in how incompetent BMW is now. Sounds like they did everything right.
.and who is to say if everyone used 0w40 we wouldn't see many failures for different reasons or equal number of failures. Aren't we missing the benefits of thicker oil that are not present in less robust 0w40? I just don't doubtwe would trade a small number of one kind of problem for another kind of problem if all people used 0w40

[SenorFunkyPants]

Originally Posted by kawasaki00

Honestly, the top of that piston looks like crap, I have looked at some engines that were clean on the top and some that were like this. This engine is an example or how poorly some of the engines seal up. You could be correct but that engine is burning so much oil it is very hard to even know what is going on with it. I hate it is apart and a lost cause now but we have taken engines that have this trend, changed to a different oil and over time they clean up. The type/brand oil can make a difference too. I am not trying to side step your question it is just difficult to answer with the pieces we have.

Thanks for that...the crown didn't look very healthy to me - the last time I had an engine apart I thought an even brownish colour was a good sign but that was in the day when fitting a bigger carburetor was a major boost to bhp!

[BMRLVR]

Originally Posted by MrStinky

So isn't it clear BMW knew what they were doing now? Funny I don't see bmlvr around chiming in how incompetent BMW is now. Sounds like they did everything right.
.and who is to say if everyone used 0w40 we wouldn't see many failures for different reasons or equal number of failures. Aren't we missing the benefits of thicker oil that are not present in less robust 0w40? I just don't doubtwe would trade a small number of one kind of problem for another kind of problem if all people used 0w40

The reason I am not chiming in is because I have been extremely busy overseeing the building of, and moving into my new house, and I just haven't had the time to be on here lately.

I didn't ever say that BMW as a company was incompetent I just stated the fact that I know how decisions made by certain departments within a big corporation can be flawed. I can make this statement because I work for a corporation that is very large and I see these types of mistakes/oversights happen often.

I still stick by my guns on my statements that the S65 is built too tight for its intended usage and oil recommendation. If BMW were using an oil with better cold flow characteristics I would probably be less uncomfortable with the clearance. Also of note is that if a thinner oil was used the increased flow rate to the bearings may very well lower the temperature of the bearings enough that it would actually result in a higher viscosity at the bearings due to significantly lower temps. Remember flow is king for keeping bearings cool!

P.S.: I don't think that it is a coincidence that the S65 and S85 are two of the only BMW engines that have no published clearances in their service information! I think that BMW AG must have realized the questions that would be raised had they published the numbers publicly.

[kawasaki00]

Originally Posted by MrStinky

So isn't it clear BMW knew what they were doing now? Funny I don't see bmlvr around chiming in how incompetent BMW is now. Sounds like they did everything right.
.and who is to say if everyone used 0w40 we wouldn't see many failures for different reasons or equal number of failures. Aren't we missing the benefits of thicker oil that are not present in less robust 0w40? I just don't doubtwe would trade a small number of one kind of problem for another kind of problem if all people used 0w40

He is building a house right now, he has better things to do than banter with all of us all day. Some of us talk on a personal level on the phone to each other even thoug we have never met.
That was pretty much a douche statement.
I see he already responded to this so nevermind.

[kawasaki00]

Originally Posted by SenorFunkyPants

Thanks for that...the crown didn't look very healthy to me - the last time I had an engine apart I thought an even brownish colour was a good sign but that was in the day when fitting a bigger carburetor was a major boost to bhp!

I agree with you 100% on that.
Oh the days of the carburetor. Letting normal people go really fast with minimal money. LOL

[SenorFunkyPants]

Originally Posted by kawasaki00

I agree with you 100% on that.
Oh the days of the carburetor. Letting normal people go really fast with minimal money. LOL

Definitely.
Some of the best times I spent with my Dad as a kid were when we worked on old Mini Cooper S trying to get it repaired in time for me to go to work the next morning.
There wasn't much on it that didn't get rebuilt (the engine 4 times!)...we sleeved and skimmed the crap out of the block so much that it needed 101 leaded fuel to run properly.

[regular guy]

Q: Do you recall if the signs of detonation were predominantly on supercharged over NA bearings? Or did you see signs on each?
A: It was all supercharged engines. The NA engines didn't show signs of detonation.

Dark Green are my additional words.

[JRV]

Thanks RG. There's a lot to regurgitate but let me know if I got this right:

Clearance is fine but there is obvious signs of oil starvation

Using proper viscosity for the climate, clearance and driving conditions apply to all engines

Thick enough oil recommended though to film/protect bearings when engine is under high load

Increased timing, low octane, oil starvation, and blowers all can contribute to the grenading. The NA engines do not show detonation but the "blown" motors do. Both show signs of oil starvation however.

The sky really is falling.

Seriously though,is there another reason that is causing the oil starvation other than oil too thick to flow thru clearance. Is it possible that adding half a quart more oil may help?

[DLSJ5]

Originally Posted by MrStinky

So isn't it clear BMW knew what they were doing now? Funny I don't see bmlvr around chiming in how incompetent BMW is now. Sounds like they did everything right.
.and who is to say if everyone used 0w40 we wouldn't see many failures for different reasons or equal number of failures. Aren't we missing the benefits of thicker oil that are not present in less robust 0w40? I just don't doubtwe would trade a small number of one kind of problem for another kind of problem if all people used 0w40

How is it clear? Clevite said the thickness of the oil may have caused the wear, BMW is saying to use TWS (a thick oil), which would indicate in that case they didn't know what they were doing according to Clevite, if true.

I did a search in this thread, I can't find where BMLVR said BMW was incompetent, but even if he did, I think most of us are smart enough to put it into context. He obviously holds BMW in high regard, he bought an M3 and doesn't plan on selling it.

While I think the Clevite rep is smart, knows what he's doing and I appreciate what he's done for us, that doesn't mean he's totally right, remember they made the bearings that are being analyzed, lol.

[gatorfast]

Originally Posted by DLSJ5

While I think the Clevite rep is smart, knows what he's doing and I appreciate what he's done for us, that doesn't mean he's totally right, remember they made the bearings that are being analyzed, lol.

Pretty sure they just make the bearings to the specs bmw provides....

[DLSJ5]

Originally Posted by gatorfast

Pretty sure they just make the bearings to the specs bmw provides....

True, but how does one really tell if the excessive wear is oil starvation from a possible tight clearance issue or from too thick an oil? Either way if it's one of the other and if true, it means BMW may have got one of them wrong.

[chris719]

If they didn't get something wrong, there wouldn't be engines failing.

[MrStinky]

Originally Posted by chris719

If they didn't get something wrong, there wouldn't be engines failing.

Every brand have failing engines . And why don't more people see m forced to perform a balancing act
1. Engine life and oil film strength by more evenly spreading out forces on film. Both require tighter clearances and they had longevity goal and oil film goal
.2. 10w60- as people pointed out first it sheers to 50 weight immediately, then given its viscous it holds heat and for given engine temp probably stays hotter than lighter oil which also makes tws thinner at these temps. So its really not behaving like a 60 weight. They had to find something with strong enough film while still flowing through bearing clearance and maybe 10w40 flows a bit better but if tws still flows well and provides more cushion than although not perfect, it provided most overall protection.
.
Given we don't know all this it seems reasonable they had no perfect choice and went with the best compromise.

Take out failed supercharged engines and there are a handful of NA failures

[regular guy]

Originally Posted by MrStinky

Given we don't know all this it seems reasonable they had no perfect choice and went with the best compromise.

Or the choice could have been driven by oil sponsorship. We already had one person in here mention that with oil sponsorship, Castrol pays for some certain percent of all engine failures to BMW. I don't remember the exact perfectage, but I seem to remember it was quite a large percentage.

Take out failed supercharged engines and there are a handful of NA failures

This thread has always been about NA engines over supercharged engines; and it was never about engine failures...but about clearances and measurements and trying to understand why BONE STOCK motors were failing.

[Rupes]

I see some of the engine failures being listed as "catastrophic" and others less so. Do rod bearing issues generally result in the need for an entirely new engine?

[swamp2]

Originally Posted by kawasaki00

the NA motor that was looked at by myself and our guys did not show the detonation. Some of the SC engines I am sure probably do, havent looked at them so your blanket first statement is false.

Your examination of a single engine without any sign of detonation was clearly used to argue that detonation was not at all a possible contributing factor to this overall situation. Now whether you specifically stated or implied this, I won't reserach or dwell on.

Originally Posted by kawasaki00

We all knew what they are gaining but there is a line of what are we getting vs what are we giving up.

I asked repeatedly of the readers here to provide the advantages from tighter clearances and aside from a (marginally) quieter engine not a single benefit was brought up.

Originally Posted by kawasaki00

What we gave up is huge because the pictures of failures and bearings that are beat out just keep piling up.

Are any of this "vast" numbers of failures making into the "database" here on this forum? The worst case scenario there indicates a 0.1%-0.5% failure rate. This range attempts to account for most of the non forum reported cases. The "math" is very approxximate but still a reasonable estimate. This problem just isn't the massive tragedy it has been made out to be.

Originally Posted by kawasaki00

Ask yourself this....
When we bought the car they told us up front before the paperwork was signed that many cars would not make it to 100k miles without blowing the bottom end out would you still have bought it?

I try to react and make decisions based on real numbers (usually statistics and often uncertain, but based on the above % my answer is simply, yes.

[swamp2]

Originally Posted by kawasaki00

everytime the car starts there is I dont know one maybe 2 or 3 revolutions where it goes through the residual layer and slightly wipes the bearing before the pumped oil gets there. This is why the engines are running as long as they are, it is happening very slowly and very small amount of it is happening at a time.

Wait, in your opinion this is solely a start up issue or a high rpm issue? What you are describing above is not starvation from lack of flow but starvation from a total absence of an oil film on start up. It does not follow from the very basics of capillary action that in the downtime between car shut off and start up that the oil in the bearings leaves the gap. What's next - there are air bubbles or a significant "line" of air inside the crank oil passages??

I find the claim that the engine is oil starved enough to get metal to metal contact at start up just about as hard to swallow as BMW M engine engineering massively screwed up their clearances.

[regular guy]

Originally Posted by Rupes

I see some of the engine failures being listed as "catastrophic" and others less so. Do rod bearing issues generally result in the need for an entirely new engine?

I would say a bearing failure usually does not result in the need for an entirely new engine. I would think most of the time a bearing failure will make itself know through a loud knocking sound. Most drivers will pull over immediately knowing something isn't right and have the problem investigated. When this happens, worst case you need to get a new crankshaft, but most likely even the crank can be fixed to run again. Much more likely a rod journal is beat to hell and the connecting rod cap might now be deformed by heat. Still no need to replace the entire engine here. All of these problems can be fixed. They're expensive, but they can be fixed.

A catastrophic engine failure is when things go a little to far and you end up with a block that has holes in it. If the rod gets too hot due to bearing failure, I believe it can momentarily weld itself to the crank (experts please correct me here). When this happens, the rod stick to the crank. The momentum of the moving crank is so great that the rod snaps, rod bolts may break, pistons get broken, and a hole is usually found in the block. This type of failure is catastrophic and needs a complete engine replacement. Compared to a normal bearing failure that is caught in time, I think this type of failure is much less common.

[swamp2]

Originally Posted by regular guy

The momentum of the moving crank is so great that the rod snaps, rod bolts may break, pistons get broken, and a hole is usually found in the block. This type of failure is catastrophic and needs a complete engine replacement.

Couldn't at least one of the heads typically be saved and both if no pistons failed catastrophically? Under warranty you would most likely get an entirely new "short engine" as BMW calls it, but doing the work out of warranty that might not be the least expensive route.