Break-in Procedure

[digger]

Rod bearings have wear patterns. I believe it says dont exceed like 50% or 60% load along with the other stuff. I don't really think it matters about load variation, just that a certain amount isn't exceeded. Most of my break in miles were highway miles. Our engines are known to have tighter clearances so it'd be better to heed the warning. BMWs in general have tight clearances so do follow the TSB. It's not just talking about engines break in, it specifically refers to bearings needing 1200 miles.

the wear pattern should not be there after 1,200 miles they are supposed to look mint. the clearances may be tight will still be tight after the break in as they dont get worn away/relieved to the right clearance .....so what does the break in achieve? hint: nothing its just a generic procedure

[Arith2]

the wear pattern should not be there after 1,200 miles they are supposed to look mint. the clearances may be tight will still be tight after the break in as they dont get worn away/relieved to the right clearance .....so what does the break in achieve? hint: nothing its just a generic procedure

It's not generic. It's S54 specific. There is wear on the bearings after a few hundred miles whether you think there is or not. Leaning towards the side of who cares isn't the way we should treat our cars. I wouldn't treat a customers car this way. Just because most engines don't do this or even need it doesn't mean ours should be lumped in the same pile. You can disagree with the TSB but I wouldn't advise people ignore it.

[enjoy_m3]

Bmw also says to do the break in procedure as part of the rod bearing replacement SIB

You are correct, I wasn't dismissing bearings. Only pointing out other aspects to consider.

[digger]

It's not generic. It's S54 specific. There is wear on the bearings after a few hundred miles whether you think there is or not. Leaning towards the side of who cares isn't the way we should treat our cars. I wouldn't treat a customers car this way. Just because most engines don't do this or even need it doesn't mean ours should be lumped in the same pile. You can disagree with the TSB but I wouldn't advise people ignore it.

i meant generic in that its clearly not a rod specific break-in, what does 100 mph have to do with rod bearings? So WOT is ok even though the loads on bearings at peak torque ~4900 rpm are just as high if not higher than the tensile loads > 5,500 rpm ?

If the bearings last 60,000-100,000 miles then the wear after 1,200 would be 1-2% of the wear which is negligible (its more likely nonlinear with accelerated wear at end of life so its negligible). the bearings are not abradeable you aren't waiting for them to self clearance or of for surfaces to bed into each other like other areas inside the engine.

i encourage people to think about things not blindly follow nonsense just because BMW says so. About the only think i'd do is run the oil and filter for a very short interval in case some crap got in during the change out so it gets flushed out.

[erickhoyos]

i meant generic in that its clearly not a rod specific break-in, what does 100 mph have to do with rod bearings? So WOT is ok even though the loads on bearings at peak torque ~4900 rpm are just as high if not higher than the tensile loads > 5,500 rpm ?

If the bearings last 60,000-100,000 miles then the wear after 1,200 would be 1-2% of the wear which is negligible (its more likely nonlinear with accelerated wear at end of life so its negligible). the bearings are not abradeable you aren't waiting for them to self clearance or of for surfaces to bed into each other like other areas inside the engine.

i encourage people to think about things not blindly follow nonsense just because BMW says so. About the only think i'd do is run the oil and filter for a very short interval in case some crap got in during the change out so it gets flushed out.

Is everything okay at home? You wanna talk about some stuff? You seem a little upset at the fact that people genuinely care about treating their engines well rather than mash the throttle like a junkyard LS with no oil/coolant.

[digger]

Is everything okay at home? You wanna talk about some stuff? You seem a little upset at the fact that people genuinely care about treating their engines well rather than mash the throttle like a junkyard LS with no oil/coolant.

You may think you’re clever but I’m actually ok with people following the procedure just because it’s the procedure but not with spreading bs about why it’s needed as some kind of justification when there is no actual technical merit let alone a logical hypothesis for why it is needed . It’s spreading misinformation and there’s enough of that already

[Obioban]

i meant generic in that its clearly not a rod specific break-in, what does 100 mph have to do with rod bearings? So WOT is ok even though the loads on bearings at peak torque ~4900 rpm are just as high if not higher than the tensile loads > 5,500 rpm ?

If the bearings last 60,000-100,000 miles then the wear after 1,200 would be 1-2% of the wear which is negligible (its more likely nonlinear with accelerated wear at end of life so its negligible). the bearings are not abradeable you aren't waiting for them to self clearance or of for surfaces to bed into each other like other areas inside the engine.

i encourage people to think about things not blindly follow nonsense just because BMW says so. About the only think i'd do is run the oil and filter for a very short interval in case some crap got in during the change out so it gets flushed out.

105mph is to avoid the high loading on the engine necessary to overcome wind resistance at higher speed. WOT is also not allowed per BMW’s procedure.

[digger]

105mph is to avoid the high loading on the engine necessary to overcome wind resistance at higher speed. WOT is also not allowed per BMW’s procedure.

The breakin I just read said nothing about wot just rpm 5500 iirc and speed 100 maybe there are multiple different ones

you can do 100mph with about 75hp which isn’t really a load (force) nor is it “much” for an m3.
Speeds limits are for driveline component breakin it’s not a specific rod thing as it’s a poor definition of operational loading for an engine unless you’re dealing with a heat input with a thermally sensitive part.
Engine loads come from torque ( cylinder pressure) and inertia (rpm) which are at different moments in “time” so power isn’t even a useful rating of a rod or the bearing.

[BearDeXPS]

just rip that shit

[erickhoyos]

You may think you’re clever but I’m actually ok with people following the procedure just because it’s the procedure but not with spreading bs about why it’s needed as some kind of justification when there is no actual technical merit let alone a logical hypothesis for why it is needed . It’s spreading misinformation and there’s enough of that already

The misinformation being spread around is not needing to do a proper break in when even BMW recommends it. Think about it, would you apply full force on a broken bone right after they put on a cast?

[digger]

The misinformation being spread around is not needing to do a proper break in when even BMW recommends it. Think about it, would you apply full force on a broken bone right after they put on a cast?

Just because BMW says something doesn't mean the underlying premise is factual, i mean they are the ones that screwed up rod bearing on a bunch of engines even post s54 so how much do you trust them anyway....

misinformation is "false or inaccurate information, especially that which is deliberately intended to deceive" such as saying BMW don't have a procedure. it is not false that you don't need to do the procedure because there is no technical basis for doing it, i mean the very procedure is inconsistent with protecting rod bearings.

yeah good one, you know bones heal over time right? after the 1200 miles there is no healing or improvement over time its all downhill from the first turn of the key

[erickhoyos]

Just because BMW says something doesn't mean the underlying premise is factual, i mean they are the ones that screwed up rod bearing on a bunch of engines even post s54 so how much do you trust them anyway....

misinformation is "false or inaccurate information, especially that which is deliberately intended to deceive" such as saying BMW don't have a procedure. it is not false that you don't need to do the procedure because there is no technical basis for doing it, i mean the very procedure is inconsistent with protecting rod bearings.

yeah good one, you know bones heal over time right? after the 1200 miles there is no healing or improvement over time its all downhill from the first turn of the key

So what’s your argument here? Earlier posts suggest that you’re against break in procedures but now you’re indifferent because there’s not enough evidence to suggest doing them anyways? So you’re telling me that these people that spend hours and hours analyzing oil content and other various rod bearing related items are wasting their time doing so, just because BMW doesn’t know how to build an engine right? Sounds like you should go work for BMW and engineer and build an engine of your own that’s N/A and revs to 8K and see how that works.

And good one, indeed. Bones can still break even after they have healed.

[Icecream]

The misinformation being spread around is not needing to do a proper break in when even BMW recommends it. Think about it, would you apply full force on a broken bone right after they put on a cast?

They also recommend castrol, now shell. It could have also been insurance for them so if the bearings went again and the SA asked the customer "did you follow the break in procedure" it would provide a reason for BMW to not fix the issue for free a second time. Dealers and companies have done worse.
From a logical standpoint, it does not make sense to me to break them in. they don't need to seat, they don't increase in clearance and they are not supposed to come into contact with a perfectly machined crankshaft (even though they do, a little, over time). The lead is very soft compared to the crank and thus I would argue that one pass of the crank under load where it contacts the bearing is enough to deform (maybe not even remove any appreciable material) the bearing at that point and this probably happens thousands of times (in different areas of the bearing) before you replace the bearings anyway, well past the break-in period. Did I do it? Yes, but more so when I sell I can say yeah I did it and because it was easy enough (and because yeah, I don't build engines and might be overlooking something). YMMV.

[digger]

So what’s your argument here? Earlier posts suggest that you’re against break in procedures but now you’re indifferent because there’s not enough evidence to suggest doing them anyways? So you’re telling me that these people that spend hours and hours analyzing oil content and other various rod bearing related items are wasting their time doing so, just because BMW doesn’t know how to build an engine right? Sounds like you should go work for BMW and engineer and build an engine of your own that’s N/A and revs to 8K and see how that works.

And good one, indeed. Bones can still break even after they have healed.

If you are in the BMW says so therefore i will follow camp fair enough cant expect the average/lay person with zero technical understanding (and not interested in improving) to think much about this stuff but if you're an enthusiast don't pretend there's a technical reason for it just because BMW says to do it. The OP knows BMW says so.

It's better to understand (or try to) whats going on otherwise what will you do in life when there is no procedure. This is an enthusiast forum if you cant handle discussions and differing (informed) opinion then why are you posting in this thread? i'm all for people with alternate opinions but if you aren't prepared to be called out on them if they are flawed then..........BMW says so is not a valid opinion that adds anything useful to the discussion.

I'd give up on the bad analogies (should have used cartilage), the rod bearings will always wear out eventually if you use the engine as intended, even if you had a 6k redline they still wear out on automotive applications they are sacrificial parts. on other equipment they can outlast the equipment life when done properly

[Tones]

i meant generic in that its clearly not a rod specific break-in, what does 100 mph have to do with rod bearings? So WOT is ok even though the loads on bearings at peak torque ~4900 rpm are just as high if not higher than the tensile loads > 5,500 rpm ?

If the bearings last 60,000-100,000 miles then the wear after 1,200 would be 1-2% of the wear which is negligible (its more likely nonlinear with accelerated wear at end of life so its negligible). the bearings are not abradeable you aren't waiting for them to self clearance or of for surfaces to bed into each other like other areas inside the engine.

i encourage people to think about things not blindly follow nonsense just because BMW says so. About the only think i'd do is run the oil and filter for a very short interval in case some crap got in during the change out so it gets flushed out.

This dude gets all his news from the youtubes😂😂😂

Sent from my Pixel 3 XL using Tapatalk