Rod Bearing Replacement @78,000 kms - Perth

[Charlievee]

Originally Posted by Nugget

That's exactly what happened.

You didn't pull your replaced rod bearings out to look at them did you?

[cplagz]

Originally Posted by Shan75

Additionally - in my humble opinion - some of you are giving BMW way too much credit in relation to them taking ownership of issues.

I think a large portion of this thread is paralysis by analysis. Either do the bearings or don't do them, the way I looked at it was $3k for peace of mind or potentially $10k+ if something bad happens. Many of us drive our cars the way they were intended and I pulled my bearings at 55k and wouldn't have wanted to go much further on them.

BMW has always had issues that they won't admit/pay for (in aus anyway). My e38 had the nikasil block issue, oil pump bolts backing out and hitting timing chain (which BMW WA said wouldnt happen when I told them during timing chain service, 3 weeks later it happened and they had to tear the bottom end apart again). S54 bearings, S65 bearings, S85 bearings the list goes on. Whilst only 1% of failures are "reported" the large majority of owners wouldn't venture into forums and just take BMW at their word and cop the bills to fix it, or flog it off.

[M3 hacker]

Exactly - well said...

[Charlievee]

Originally Posted by cplagz

I think a large portion of this thread is paralysis by analysis. Either do the bearings or don't do them, the way I looked at it was $3k for peace of mind or potentially $10k+ if something bad happens. Many of us drive our cars the way they were intended and I pulled my bearings at 55k and wouldn't have wanted to go much further on them.

BMW has always had issues that they won't admit/pay for (in aus anyway). My e38 had the nikasil block issue, oil pump bolts backing out and hitting timing chain (which BMW WA said wouldnt happen when I told them during timing chain service, 3 weeks later it happened and they had to tear the bottom end apart again). S54 bearings, S65 bearings, S85 bearings the list goes on. Whilst only 1% of failures are "reported" the large majority of owners wouldn't venture into forums and just take BMW at their word and cop the bills to fix it, or flog it off.

No, not at all if you’re referring to my replies; I believe quite the contrary. The people who swap out the bearings do their diligence by researching the issue, the more they look into it, the more convinced they are that there is an issue when likely there is not. This is because you only find information relevant to there being an issue (ask your doctor about people who self-diagnose their symptoms on google). I see the same information spread across all corners of the internet, (although I’ll give props to Assimilator1 in that he has researched the issue in much more depth and detail than most), it still narrows down to the same concern of how the bearings looks when they are removed, and I can’t get away from the fallacy in the belief that it was probably nearing failure due to its appearance. The rate of failure would be much higher if this was the case. If the bearing change gives you peace of mind, then do the change. Nothing better than peace of mind, who wants to live under constant stress and fear? However, the logical thing to do in my opinion, based off what has been widely accepted as facts across these boards, is to not do the change. But hey, to each their own. I don’t claim to be right, I’m just sharing my logical deductions based off the information I deem to be reliable and why “I” have decided against doing a change.

I don’t disagree with you, I got mine from a dealer and I can say that I didn’t have the best experience post purchase on multiple fronts, but a lot of the time these issues are confined to the dealership (as the liability sits with them unless BMW Australia corporate releases a directive on the issue), and BMW Au corporate almost always align their directives with what happens in other parts of the world. However, if you think “the majority” of people in this day and age is going to foot a $30k+ bill and flip off a car at a huge loss without doing any diligence to see if it’s a common issue amongst other vehicles, or speak to people who may be aware of the issue… then, yeah… nah… don’t think so. Even if there are a few that go under the radar, it won't significantly alter the failure rate drastically.

I'll just also add that the majority of E92 M3 owners are not on these forums, and their bearings likely look the same as the ones pulled out as those on these forums. It would be illogical to assume the majority of them would be nearing or have experienced an engine failure wouldn't you say? Or do you think they're all lining up at dealerships to get their bearings changed? Because there's quite a lot of them!

[ten3]

[QUOTE=Ashley_rj;25774263]Hey Nam, I recon the effect you want wouldn’t be from having the power button on but by having the gear box mode in a more aggressive setting that would keep the revs higher and kick down sooner. It would make the fuel consumption worse and it would be hard to know if there was any effect on longevity...

Originally Posted by ten3

Great discussion guys, thank you.
while the argument is on going, i think this guy (below) made a good point to protect my engine by driving with Power mode on all the time. That way my car wont go to high gear often. what do you guys think ?

Thanx Ash,
How do i set my gearbox doing so ?
Cheers

[ten3]

Thanx Charlievee,
Well done.

[Shan75]

I think there are a lot of good points in this thread..

None of them are necessarily wrong either. I think everyone has to play it the way they see it.

My peace of mind is worth the cost of bearing replacement.

Enough evidence - at least in my opinion - to indicate there is no harm in doing the work.

Not doing the replacement requires supreme confidence M engineers got it right.

Dunno about that.

My dad always said “bet what you can afford to lose”.

I can afford the cost of a bearing set replacement....so I’ll take that bet.

S65 rebuild is another matter! : )
Stakes are too high for me.

[Assimilator1]

Same, I can afford to buy shells & accessories, I physically don't have the cash to buy a 2nd hand engine (assuming they're £7-10k). And now I've proven (to myself at least) that oil analysis doesn't always catch failing bearings, I'm going to change them. Joy!

I'll just also add that the majority of E92 M3 owners are not on these forums, and their bearings likely look the same as the ones pulled out as those on these forums. It would be illogical to assume the majority of them would be nearing or have experienced an engine failure wouldn't you say?

For now, yea I reckon you're right, I guess we won't really know overall for the long term for another 10-20yrs?
My hope is in the long run M3s with fresh bearings are worth twice as much!

[Assimilator1]

Oh, I meant to post this earlier.

The 1st photo is a rare case or S65 OEM bearings coming out good, followed by how they typically look. Along with some chat about it from an engine builder.

Originally Posted by deansbimmer

The entire bearing shell is not wearable material. You cannot simply look at a bearing and determine how much more "meat" there is. The shell's structural component is steel. The babbit (dissimilar wear surface) is lead/copper or tin/aluminum. The crank is steel. Once the very thin babbit layers wear down, these similar metals weld together and you get a spun bearing. Many bearings spin well before that while the crank is riding on the exposed copper. Engines fail due to one failed bearing. They don't all seize up at once. Failed engines usually have seven journals that look exactly like the OP's, except for one cylinder (or main) which spun and shows visible copper or steel.

It has been said hundreds of times over...You Can't know when your bearings are going to fail. You can't look at a used bearing and say "yep, that one was only good for another 4,296 miles"... All you can do is go through with the service and move on with the peace of mind. The general consensus as to why some fail early and some later is unfavorable vs favorable tolerance stacking.

Yes, I'm a believer because I run a shop and have a finger on the pulse of the issue. And that's not because I get money to replace abnormally worn bearings, but because I see the huge number of failures which are astronomically out of normal proportion. It's a thing. It's not normal. Owners can believe it or not, it doesn't matter to us shops. Consider how many failures have been averted by owners changing their bearings? I guarantee you that if nobody ever did another bearing change ever, then we'd stay just as busy selling more replacement engines instead.



FYI, this engine was obviously built with a favorable tolerance stack. This is how bearings should look coming out of an S65 (of any mileage):



Instead, we constantly see them coming out like this:

[Charlievee]

Originally Posted by Shan75

I think there are a lot of good points in this thread..

None of them are necessarily wrong either. I think everyone has to play it the way they see it.

My peace of mind is worth the cost of bearing replacement.

Enough evidence - at least in my opinion - to indicate there is no harm in doing the work.

Not doing the replacement requires supreme confidence M engineers got it right.

Dunno about that.

My dad always said “bet what you can afford to lose”.

I can afford the cost of a bearing set replacement....so I’ll take that bet.

S65 rebuild is another matter! : )

Stakes are too high for me.

I agree, do not put a value on your mental health. If you believe it gives you peace of mind, go ahead and do it.

Do I have “Supreme confidence in M engineers”? not so much. But confident enough based off the information I’ve processed across various sources.

On the betting comment, I’m a poker player. I’ll always bet the pot according to my odds (I’m calculative in that way, may be an engineer thing). So if I bet $1, and my odds are 1:2, I’m expecting a $2 return on a win (or close as possible) or it’s not a value bet. $3-4k for a rod bearing replacement for a <1% failure? Yeah, nah.. I’ll take my chances.

There has also been quite a bit of information I’ve overlooked for the sake of the discussion (but you may have noticed I touched on them without elaborating since my point had been focused elsewhere).

e.g. Clearance is only a theory, and there is a case shown on these forums of a guy using OEM calico coated bearings on a supercharged engine, and it showed zero wear after 24k kms. Since coating adds thickness to the OEM bearings, it goes to support the notion that clearance is not the issue. Hence, if I was to do mine, I’d be removing the engine, measuring clearances properly, doing mains and rod bearings, and using OEM bearings with a calico coating.

Also, on the main bearings. It almost seems that whenever they are removed, they exhibit the exact same wear as the rod bearings. So it makes no sense to be changing out the rod bearings and not touching the main bearings. It is reasonable to deduce that since the main bearings exhibit the same wear pattern as the rod bearings, the mode causing the wear is the same. If the wear is also at the same severity, this would mean that the likelihood of an occurrence of a failure is the same across mains and rod bearings (if you believe the wear seen is causing the failures). It’s only logical.

Refer to the link below on an example of what mains looked like when pulled out together with rod bearings:
https://www.m3post.com/forums/showthread.php?t=1468959

Originally Posted by Assimilator1

Same, I can afford to buy shells & accessories, I physically don't have the cash to buy a 2nd hand engine (assuming they're £7-10k). And now I've proven (to myself at least) that oil analysis doesn't always catch failing bearings, I'm going to change them. Joy!

I'll just also add that the majority of E92 M3 owners are not on these forums, and their bearings likely look the same as the ones pulled out as those on these forums. It would be illogical to assume the majority of them would be nearing or have experienced an engine failure wouldn't you say?

For now, yea I reckon you're right, I guess we won't really know overall for the long term for another 10-20yrs?

My hope is in the long run M3s with fresh bearings are worth twice as much!

I’ve actually researched prices on the engine, which was also part of why I’ve also decided against any bearing change for me.

You’re from the UK? In Australia, I’ve seen the S65 sell from 8k AUD through to 25k AUD. 8k being a high km example and 25k for a new one. Averaging around the 14k for an 100km example.

A rod bearing change here cost up to 4.5k (depending on where you get it done). There’s no value in paying that sort of money to do only rod bearings, when you can buy an engine for around twice that cost. Then rebuild it with new seals, gaskets, rings and bearings. I wouldn’t mind a high km example if it was going to be rebuilt anyway. I’d do it myself, but even if you’re a person thay isn’t capable, when you have an engine out of the car it’s much easier (and cheaper) to work on if you can engage the right sources. A few hundred bucks and an engine builder will pull it together for you. Another few hundred and you can get the engines swapped in. Circa 10k for a new engine, 12k installed (if paying for the labour).

Makes no sense they’d be worth anything more. I personally believe that time will go to show the bearings will get worse because clearance is probably not the cause of wear. But hey, I won’t stop you from hoping.

[cplagz]

Originally Posted by Charlievee

A rod bearing change here cost up to 4.5k (depending on where you get it done). There’s no value in paying that sort of money to do only rod bearings, when you can buy an engine for around twice that cost. Then rebuild it with new seals, gaskets, rings and bearings. I wouldn’t mind a high km example if it was going to be rebuilt anyway. I’d do it myself, but even if you’re a person thay isn’t capable, when you have an engine out of the car it’s much easier (and cheaper) to work on if you can engage the right sources. A few hundred bucks and an engine builder will pull it together for you. Another few hundred and you can get the engines swapped in. Circa 10k for a new engine, 12k installed (if paying for the labour).

Have you ever built a motor? Either yourself or paid someone, because I can almost guarantee to you to rebuild a S65 in Aus the way you are saying you should be budgeting double roughly what you think it is. I built a M20 myself and bought all the parts I could as cheap as possible and that still pushed close to $15k, I'd hate to see the ///M tax on all the little bits and pieces you need to buy.

[Charlievee]

Originally Posted by cplagz

Have you ever built a motor? Either yourself or paid someone, because I can almost guarantee to you to rebuild a S65 in Aus the way you are saying you should be budgeting double roughly what you think it is. I built a M20 myself and bought all the parts I could as cheap as possible and that still pushed close to $15k, I'd hate to see the ///M tax on all the little bits and pieces you need to buy.

$15k to rebuild an inline 6? You could have probably walked into a shop and got it done for under $10k with labour, hot tanked, honed and decked. I'm thinking replace seals, gaskets, rings, and bearings. I admit I haven't researched prices on M parts; but say 1k rod bearings and rod bolts, 800 main bearings, 200 head gasket, 1k rings, seals here and there and bolts will be a few hundred at most. Bear in mind I'd have a donor engine I could take parts from. The point isn't to build a fresh motor but get to the point of a useable and reliable engine (with fresh main and rod bearings) in the unlikely case of a bearing failure. But you're probably right, I've probably underestimated parts considering it's an M3. Cant imagine by more than a few thousand tho.

[Shan75]

Southern BM were still doing a fixed price on the bearing replacements as well....was low $3k if I recall.

In the unfortunate event we a right and you did spin a bearing - would point out any used engine you buy is likely still gonna need bearings done as well.

Either way...it’s all money I would rather not spend. Bearings seems like the lesser evil.

My vascular surgeon charges less than a good engine builder as well ; )

I love my m3 tho. I bought it knowing all this.
Mine has 85000kms and when I bought it - thought I would just hold out till it clocked over 100 before addressing the problem.

More I drive it - more paranoid I get though.

I redline it and get pictures of bearings with irregular wear flashing thru my mind.

Ruins the buzz....almost ; )

[Charlievee]

Originally Posted by Shan75

Southern BM were still doing a fixed price on the bearing replacements as well....was low $3k if I recall.

In the unfortunate event we a right and you did spin a bearing - would point out any used engine you buy is likely still gonna need bearings done as well.

Either way...it’s all money I would rather not spend. Bearings seems like the lesser evil.

My vascular surgeon charges less than a good engine builder as well ; )

I love my m3 tho. I bought it knowing all this.
Mine has 85000kms and when I bought it - thought I would just hold out till it clocked over 100 before addressing the problem.

More I drive it - more paranoid I get though.

I redline it and get pictures of bearings with irregular wear flashing thru my mind.

Ruins the buzz....almost ; )

Try not to picture your main bearings then! They almost certainly look like the rod bearings you pulled out with irregular wear.

Oh yeah, if you spin a rod bearing. Theres a chance you can get a new crank and rod. What's that going to set you back? 3-4k in parts?

Main bearing will almost certainly result in a damaged engine block which means a new engine.

There's just no value in doing rod bearings... makes no sense to me. But to each their own.

[Assimilator1]

Hmm, although I don't have solid figures, having looked through the 1st 60 odd of the blown engine registry thread, rod bearing failures far out number main bearing failures. (btw I'm working my way through that list to see how many are actually bearing failures, most are in that 1st 60 odd I've checked to date. I need to add more info to my list, it's a WIP ).

So atm, I disagree about only doing the big end bearings being valueless, the chance of the mains letting go seems to be far less than the big ends, & the cost of changing the mains is far higher.
IIRC engine builder Deansbimmer has also noticed far fewer mains problems vs big end bearings.

[Charlievee]

Originally Posted by Assimilator1

Hmm, although I don't have solid figures, having looked through the 1st 60 odd of the blown engine registry thread, rod bearing failures far out number main bearing failures. (btw I'm working my way through that list to see how many are actually bearing failures, most are in that 1st 60 odd I've checked to date. I need to add more info to my list, it's a WIP ).

So atm, I disagree about only doing the big end bearings being valueless, the chance of the mains letting go seems to be far less than the big ends, & the cost of changing the mains is far higher.
IIRC engine builder Deansbimmer has also noticed far fewer mains problems vs big end bearings.

There's really nothing conclusive from doing that because if your mains spin, it's almost certain your rod bearings will fail unless you pick it up early. So unless everyone in that thread did an engine tear down, you can't conclusively say the rod bearing failures were not due to a main bearing failure.

If I was to do a rod bearing change, I'd save a bit more and get the mains done together with OEM coated bearings. The chances really are you should hear a knock if it's your rod bearings, or your crank and rods can be replaced. Unless you're unlucky and a rod goes through your block or you have a secondary main failure. Again, I like my chances the more thought this gets.

There's a fallacy in logic here, if you deadset believe the wear is causing the failure on rod bearings, it's the same wear on the mains!!! In all your research, have you seen an engine which has mains with no wear compared to the rod bearings?

[Shan75]

I would agree - main bearing failure does appear to be less frequently mentioned on forums I’ve read. Although that’s not evidence as such...just my opinion.

Can’t comment on main bearing wear either...

If I didn’t do the rod bearings, and they failed, damaging the engine - I would be kicking myself.

Having the preemptive warning and not acting on it...would be hard not to kick your own ass a little.

Alternatively - If I did the rod bearings and main bearing still failed, I think I would be of the opinion the engine was doomed regardless.

I’d be heartbroken...but feel I would be less critical of myself in that situation.

As someone eluded to earlier - can’t put a price on a good mental state.

I would always wonder “what if” If I never attended to rod bearings and engine shit itself.

Rather know I did everything I could reasonably afford.

[Charlievee]

Yeah, I can definitely empathize with that. I can understand the rationalization behind your decision for sure.

It seems most people are willing to make that call on emotion rather than logic. Paying 3-4k hoping to reduce risk from 1% is absurd to me (probably less considering actual failures due to other reasons, and main bearing attributed failures). But I suppose my decision is based on believing the risk is calculated and there's no real value/benefit added by doing the rod bearings. I mean that's clearly what all the reliable (non-subjective and biased) evidence suggests.

This bearing replacement thing never sat right with me. I'm more convinced now than ever that there's more to the story than we know. Just doesn't seem right the rod bearings replacements are pushed and nothing on mains despite wear on both. How convenient is it that the rod bearings are cheap to produce and easy to replace, but demand a high price for both product and service? Its like the perfect price point to get people in for a replacement.

But who knows for certain, this is just my 2c.

[Assimilator1]

Originally Posted by Charlievee

There's really nothing conclusive from doing that because if your mains spin, it's almost certain your rod bearings will fail unless you pick it up early. So unless everyone in that thread did an engine tear down, you can't conclusively say the rod bearing failures were not due to a main bearing failure.

If I was to do a rod bearing change, I'd save a bit more and get the mains done together with OEM coated bearings. The chances really are you should hear a knock if it's your rod bearings, or your crank and rods can be replaced. Unless you're unlucky and a rod goes through your block or you have a secondary main failure. Again, I like my chances the more thought this gets.

There's a fallacy in logic here, if you deadset believe the wear is causing the failure on rod bearings, it's the same wear on the mains!!! In all your research, have you seen an engine which has mains with no wear compared to the rod bearings?

Re your 1st point, err no, because very, very few people have come back reporting mains & rod bearings failing subsequently. Your logic fails there.
If the mains were failing at that point then the engine wouldn't last long at all after that, think in terms of a few hundred miles if you're lucky.

Main bearings aren't a bit more to do than rod bearings, as I've already told you they're a lot more.
About the rod knock, I thought so too, but some people (including at least 1 engine builder, Malek, photos here & report here) report just a light ticking or nothing at all (as in Maleks case).
If the crank gets irreparably damaged due to a rod bearing failure, then I know a new crank alone costs at least ~£3k (here in UK).
Also, Deansbimmer reported that when people here a knock it's usually already too late for the crank, IIRC he said he's managed to save 2 engines which had got to that stage.

Re strip down to look at mains when doing rod bearings, true most people don't so that. But as I said above, if it was as big a problem then their would have been plenty of people reporting that back too by now!

There's a fallacy in logic here, if you deadset believe the wear is causing the failure on rod bearings, it's the same wear on the mains!!!

Nope, your logic is flawed here too, you're assuming the mains are under the same conditions as the rod bearings, they are not, any number of differences could explain why they fail (so far that we've seen in this not new problem) far less often than rod bearings. And, as I've said before, so far from what I've seen reported of failed engines, rod bearings are by far the more common cause. If I find that later in the list mains are more often reported as the cause of failure, I'll let you know (& others) know! (in that thread) .

Although the rod bearings are easier to do than the main bearings by far, that doesn't mean they are easy per se, seeing as it takes 8-10hrs+!!
If you could simply drop the sump off to get to the rod bearings (like you could on many older cars, some newer), then yes that would be easy!

And again you're focusing on the <1% engine failure rate & ignoring the large number (but yes, not all) of rod bearings showing significant premature wear (even if you don't include the ones with marginal wear). I at some point am going to collate links & photos of rod bearings (from any engine) with normal wear with at least several 10s of thousands of miles on them for comparison.

I mean that's clearly what all the reliable (non-subjective and biased) evidence suggests - no it doesn't! lol

Anyway, I'm not trying to force you to do your rod bearings, I'm just trying to give you a clearer picture of the gamble you're taking, IMO you're being overly optimistic (and illogical) about it. Anyway, your choice & I don't want to expend anymore time on this discussion really .

I'll keep my fingers crossed for ya.

[Charlievee]

Originally Posted by Assimilator1

Re your 1st point, err no, because very, very few people have come back reporting mains & rod bearings failing subsequently. Your logic fails there.

If the mains were failing at that point then the engine wouldn't last long at all after that, think in terms of a few hundred miles if you're lucky.

Main bearings aren't a bit more to do than rod bearings, as I've already told you they're a lot more.

About the rod knock, I thought so too, but some people (including at least 1 engine builder, Malek, photos here & report here) report just a light ticking or nothing at all (as in Maleks case).

If the crank gets irreparably damaged due to a rod bearing failure, then I know a new crank alone costs at least ~£3k (here in UK).

Also, Deansbimmer reported that when people here a knock it's usually already too late for the crank, IIRC he said he's managed to save 2 engines which had got to that stage.

Re strip down to look at mains when doing rod bearings, true most people don't so that. But as I said above, if it was as big a problem then their would have been plenty of people reporting that back too by now!

Nope, incorrect. According to deansbimmer (you keep referencing) “where the mains failed and spun first, and the resulting lack of oil to the rods caused them to spin too. Since you can’t really hear a main failure there’s no indication of trouble until it takes out the rod bearings and they start knocking.” So unless everyone on the list has done an engine tear down, they likely will have no idea the mains have failed and have just assumed it was a rod bearing failure. The guy who posted that thread assumed it was his rod bearings only, but only discovered the mains were the culprit after the tear down.

https://www.m3post.com/forums/showthread.php?t=1565239

Never said they were a bit more work, I’m saying it makes no sense to do just the rod bearings when the main bearings will almost certainly show the same wear. Hence, I would change both if I was to do one.

Originally Posted by Assimilator1

Nope, your logic is flawed here too, you're assuming the mains are under the same conditions as the rod bearings, they are not, any number of differences could explain why they fail (so far that we've seen in this not new problem) far less often than rod bearings. And, as I've said before, so far from what I've seen reported of failed engines, rod bearings are by far the more common cause. If I find that later in the list mains are more often reported as the cause of failure, I'll let you know (& others) know! (in that thread) .

The wear looks the same! So now you’re saying the failure is attributed to other “conditions”? You’re basically saying the wear isn’t the significant cause to the failure! If you’re saying that, then you’re throwing out your argument that rod bearing wear (the reason why you replace the rod bearings) is the reason for the failure! You’ve made absolutely no sense, I hope you can see how you’re contradicting yourself.

Again, the rod bearing failure reported could more than likely be a result of a main first bearing failure. Unless everyone on that list did a tear down to determine actual failure, you cannot say definitively that the failures were due to the rod bearings alone.

Originally Posted by Assimilator1

Although the rod bearings are easier to do than the main bearings by far, that doesn't mean they are easy per se, seeing as it takes 8-10hrs+!!

If you could simply drop the sump off to get to the rod bearings (like you could on many older cars, some newer), then yes that would be easy!

“Relatively” easy. So correct, rod bearings are easier to do than the main bearings by far.

Originally Posted by Assimilator1

And again you're focusing on the <1% engine failure rate & ignoring the large number (but yes, not all) of rod bearings showing significant premature wear (even if you don't include the ones with marginal wear). I at some point am going to collate links & photos of rod bearings (from any engine) with normal wear with at least several 10s of thousands of miles on them for comparison.

In your opinion, it shows significant premature wear.

You have been emphasizing that the wear on the bearings are your concern, yet you are saying other “conditions” are contributing to the failures…. So....

What about the “significant premature wear” on the main bearings????

Show main bearings where possible also. They always shows the same wear or worse.

Originally Posted by Assimilator1

Anyway, I'm not trying to force you to do your rod bearings, I'm just trying to give you a clearer picture of the gamble you're taking, IMO you're being overly optimistic (and illogical) about it. Anyway, your choice & I don't want to expend anymore time on this discussion really .

I'll keep my fingers crossed for ya.

Nor am I forcing you to not do them (nor did you ever stand a chance of convincing me otherwise really lol).

Do them if they float your boat, but based off widely accepted figures and evidence at hand, it seems sensible not to do them.

Also, based off evidence that clearance isn't even a factor, and that M Sport intended the bearings with their design clearances, who know what problems may be introduced in the long term by putting in bearings with bigger clearances.

I’m pretty clear of the picture. Thanks for your concern, but I like my chances

[Assimilator1]

Never said they were a bit more work
Yes you did, when you said (paraphrasing) 'I would put a little more aside for main bearings to be changed too'

The wear looks the same! So now you’re saying the failure is attributed to other “conditions”? You’re basically saying the wear isn’t the significant cause to the failure! If you’re saying that, then you’re throwing out your argument that rod bearing wear (the reason why you replace the rod bearings) is the reason for the failure! You’ve made absolutely no sense, I hope you can see how you’re contradicting yourself.

Why don't you read what I've written properly? I said none of the above! Stop putting words in my mouth, again!
I never said main bearing failure is due to other causes, I said main bearings are not under the same conditions! That means a totally different thing!

The wear looks the same in the 1 set of photos you've shown, that proves nothing for other engines.
And as you're still conveniently ignoring, most engines that have had rod bearings changed are still running long after they were changed. If the main bearings were on they way out too their would be mass failures of new rod bearings soon after! Get it??

What about the “significant premature wear” on the main bearings????
Who knows! But most aren't failing yet!

And no you're wrong, widely accepted figures & evidence to hand shows it is sensible to do rod bearings, unless you have other sources of evidence (let's see it then). You keep you're rose tinted glasses on if you want.

Clearance is a factor if you bother to read the papers by people who make the bearings!
Maybe M sport did intend those clearances, but didn't factor, or have control of production tolerance factors which the tight clearances left no slack for, who knows.

I'm done arguing with you seeing as you're twisting my words, ignoring obvious evidence & not bothering to read info by bearing makers I've posted.
Adios, I'm unsubscribing this thread now.

[Charlievee]

Originally Posted by Assimilator1

Never said they were a bit more work

Yes you did, when you said (paraphrasing) 'I would put a little more aside for main bearings to be changed too'

You’ve incorrectly understood. I said I would save a bit more and do the mains as well. That is relating to the money I would be putting aside. I would rather put together money and do both mains and rod bearings together. That way, there is economy in doing both while the engine is out (essentially paying for the engine to be pulled out once, to do both). You’re actually the one putting words in my mouth, as I never intended to correlate my statement to the amount of work required.

Originally Posted by Assimilator1

Why don't you read what I've written properly? I said none of the above! Stop putting words in my mouth, again!

I never said main bearing failure is due to other causes, I said main bearings are not under the same conditions! That means a totally different thing!

Let me break this down for you… It can be inferred that you are saying the wear isn’t the significant cause of the failure.

1. There is wear on the main bearings that look the same as the rod bearing wear (evident)
2. You are saying the rod bearings have wear that is causing failures (according to you)
3. LOGIC - Is it not reasonable to deduce that the wear shown on the main bearings should also be causing failures? (since the wear on the rod bearings are “significant premature wear”, then the mains also have “significant premature wear”, since they look the same!)

Now you are saying…
1. There is wear on the main bearings that look the same as the rod bearing wear (evident)
2. The wear on the main bearings aren’t of concern because there are other conditions the rod bearings experience (according to you)
3. LOGIC - Is it not reasonable to infer that since the mains show wear that appears to be the same as the rod bearings, and there other factors affecting the rod bearings which (according to you) will result in failure, then by elimination the other factors are in fact of greater significance to causing the failure than the wear? (Logically inferred according to your statements)

Originally Posted by Assimilator1

The wear looks the same in the 1 set of photos you've shown, that proves nothing for other engines.

And as you're still conveniently ignoring, most engines that have had rod bearings changed are still running long after they were changed. If the main bearings were on they way out too their would be mass failures of new rod bearings soon after! Get it??

Go look at any engine tear down which shows photos of the mains. The mains show almost the exact same wear as the rod bearings each time. Make a list of that please, since it seems you like making lists.

I just Googled it and linked any post that came up, so here's another:
https://www.m3post.com/forums/showpo...postcount=2349

That means nothing… Did you forget that greater than 99% of engines do not fail. So majority of engines wouldn’t have failed with or without a bearing change! It seems that more engines with a rod bearings change result in failure than I’d be comfortable with. I’m sure you have read this in numerous other threads on this topic on this forum, because I sure have.

Exactly my point! But don’t forget, unless you tear down the engine to determine the root cause of the failure, it’s more than likely that a main failure will have believed to have been a rod bearing failure.

Originally Posted by Assimilator1

What about the “significant premature wear” on the main bearings????

Who knows! But most aren't failing yet!

Refer to steps of inference above… you just proved the point… not so “significant” then is it?

Originally Posted by Assimilator1

And no you're wrong, widely accepted figures & evidence to hand shows it is sensible to do rod bearings, unless you have other sources of evidence (let's see it then). You keep you're rose tinted glasses on if you want.

In your opinion.

Originally Posted by Assimilator1

Clearance is a factor if you bother to read the papers by people who make the bearings!

Maybe M sport did intend those clearances, but didn't factor, or have control of production tolerance factors which the tight clearances left no slack for, who knows.

Clearance is only a theory. Do people who make bearings know more than the people who made the engine?

The clearance theory in my opinion is disproved as; M Sport didn’t change clearances designs, and also the case where one person replaced his bearings with OEM coated ones and it showed improved wear.

Originally Posted by Assimilator1

I'm done arguing with you seeing as you're twisting my words, ignoring obvious evidence & not bothering to read info by bearing makers I've posted.

Adios, I'm unsubscribing this thread now.

I’m not twisting your words. I understand the evidence, and I have read the papers by King and Clevite. I just choose not to get into a technical discussion because you’re not an expert, and nor am I. Dunning-Kruger effect, my friend, don’t be a victim.

You’re free to do what you want, I won’t stop you. Not really sure why you’re getting so riled up tho…

See you in other threads? I see you’re very active in other rod bearings threads. I’m still making my way through reading them, but I’ll have something to add in due time.