S65 Engine Main Bearing Service, Documented

jvictormp wrote

Have you guys heard of something about start stop system causing the pressure to drop when stopped, then when starting engine, letting the crank touch the main bearings?

Start-stop is bad for engine longevity.

At least the E9x lets you turn it off and forget it even exists. I had to buy and install an aftermarket device to "remember" to keep it off for my wife's Jeep.

jvictormp wrote

Have you guys heard of something about start stop system causing the pressure to drop when stopped, then when starting engine, letting the crank touch the main bearings?

It's not the start/stop system causing this, it's simply a result of turning the engine off or on.
Most wear occurs on starting up (and I assume shutting off, perhaps to a lesser degree?) as their is no oil pressure initially (just a coating of oil). So on startup (initial second or so?), yes the crank is touching the main and rod bearings, this is normal for all engines. And is part of the reason for bringing in multigrade oils and having thinner cold grade ratings (the w rating). A 0w40 oil will circulate through the oil pump and bearings etc much more quickly than a 10w40 oil.

Of course A.S.S means starting happens much more often, so more wear caused there. In theory though the engine should have tougher bearings (and starter!) to cope with it (e.g the harder tin/alu bearings. They weren't only brought in for the EU lead ban). But tougher bearings are harder on the crank.

That said, although I haven't exclusively researched it, I haven't heard of A.S.S cars having engines failed earlier than normal, has anyone else? (Let's exclude the S65 from that question! ).

deansbimmer wrote

We've used King main bearings plenty of times without issues. They just need to be installed and measured before assembly, which should be done with any engine build using any kind of bearings. BMW's color ID only works if you're simply replacing bearings in an otherwise unchanged bottom end, i.e. reusing the same crank in the same block.

So on a simple unchanging bottom end, you would go with BMW bearings over Kings bearings?

Jbonly21 wrote

So on a simple unchanging bottom end, you would go with BMW bearings over Kings bearings?

I’ve only done the rod bearings and went with MAHLE. I’ve been advised by many shops to not go with OEM bearings since they are the cause of the problem. If changing out the mains, I personally, would use the same logic although the problem that affects the No.1 main is different than that of the rod bearings. I don’t know if anyone tore down an engine with aftermarket main bearings and noticed any improvement with wear on the upper No.1 bearing still being affected by the dual chain timing system.

Jbonly21 wrote

So on a simple unchanging bottom end, you would go with BMW bearings over Kings bearings?

Nothing wrong with OEM main bearings. We recommend having them WPC treated.

deansbimmer wrote

Nothing wrong with OEM main bearings. We recommend having them WPC treated.

Is there a good alternative for the bedplate sealant, since the Loctite 193140 has been discontinued?

Jbonly21 wrote

Is there a good alternative for the bedplate sealant, since the Loctite 193140 has been discontinued?

The dealers are saying it superseded to the 5970 RTV. This is the same RTV used to seal up the diff housing cover. I'm waiting on a better answer to this too because the RTV is thicker and doesn't seem it would travel thru the injection dowel. So then a small bead needs to be applied.

Has anyone tried sending out an email to Loctite or getting a hold of them on this matter?

Researching this some more, it seems like bimmerworld came up with this:
https://www.bimmerworld.com/Genuine-BMW-Liquid-Sealant-for-Bedplate-Crankcase-Flange.html
I don't have experience with this, but also seems like another type of RTV..?

The Injectable sealant will not be available any longer. Any old stock would also be questionable as it has a finite shelf life and expiration date.

Bimmerworld page is correct. The bedplate sealant works well, but must be applied properly and minimally, with the 1mm bead. This isn't necessarily a new thought either... It's factory on many N' engines and we've seen plenty of S65 bedplates with it over the years where it was used instead of the injected sealant.

The problem is that it's easy to over-apply and that will cause issues if not paid attention to.

deansbimmer wrote

The Injectable sealant will not be available any longer. Any old stock would also be questionable as it has a finite shelf life and expiration date.

Bimmerworld page is correct. The bedplate sealant works well, but must be applied properly and minimally, with the 1mm bead. This isn't necessarily a new thought either... It's factory on many N' engines and we've seen plenty of S65 bedplates with it over the years where it was used instead of the injected sealant.

The problem is that it's easy to over-apply and that will cause issues if not paid attention to.

In that case, are you simply just applying a small "bead" on the block side of the groove? Then are you letting the RTV skin-over before adding the bedplate?

It would be nice to see the updated procedure for this. I'll have to do more research to see if that exists.

I reached out to a couple of S65 engine builders, and I was told they reached out to loctite. And it was confirmed they are no longer making that sealant. This is the new procedure and this is what mine looked like when I did it. I have done 200 miles so far.

Jbonly21 wrote

I reached out to a couple of S65 engine builders, and I was told they reached out to loctite. And it was confirmed they are no longer making that sealant. This is the new procedure and this is what mine looked like when I did it. I have done 200 miles so far.

Yes! Thank you.
That is exactly what I wanted to see.

Yea, except the AIR exert doesn't say how wide the bead should be.....

deansbimmer wrote

The Injectable sealant will not be available any longer. Any old stock would also be questionable as it has a finite shelf life and expiration date.

Bimmerworld page is correct. The bedplate sealant works well, but must be applied properly and minimally, with the 1mm bead. This isn't necessarily a new thought either... It's factory on many N' engines and we've seen plenty of S65 bedplates with it over the years where it was used instead of the injected sealant.

The problem is that it's easy to over-apply and that will cause issues if not paid attention to.

100% correct across the board.

Jbonly21 wrote

I reached out to a couple of S65 engine builders, and I was told they reached out to loctite. And it was confirmed they are no longer making that sealant. This is the new procedure and this is what mine looked like when I did it. I have done 200 miles so far.

Yeah, we were EXTREMELY frustrated with this. In our opinion, "good 'nuff" just isn't good enough. Aside from using feeler gauges, nothing we do is done by feel. Every specification in every motor we build is manually checked for certainty, especially where critical tolerances are concerned. The idea of smearing sealant onto the bed plate had me pressed. So I designed this:
https://parteeracing.com/store/other-products/uncategorized/s65-s85-bedplate-injection-tool/

Essentially, once the block is prepped and ready to check main clearances (bedplate bolted and torqued to the block), you tap the original sealant port on each side of the block with a 3/8" tap (I know, I know, it's a standard bolt size on a metric motor; I hate it too. But the sealant port is the exact diameter you need for a 3/8' tap, so using 3/8" eliminates the need to drill the side of the block before tapping it.), then go about taking your measurements as normal.

When you re-open the block to install the crank (assuming you were happy with clearances ofc), you can then clean out all debris from the tap, install the crank, re-torque the block, and once the main seals are installed, use our injection tool to inject the new BMW recommendation for bedplate sealant.

The process is extremely simple- easier IMO than the original stuff. Simply hand-thread the injection tool into the block, and then start turning the knob. The knurled knob is threaded onto the injector body; turning the knob will press the billet plunger into the injector body, which will then hydraulically force the extremely viscous sealant through the channel with ease.
The injector tool will create well over 10,000 PSI at just 14Nm of torque applied to the knob, but in our experience, far less is required- we have never needed more than our hands to inject the sealant all the way through the channel.

Picture of the tool doesn’t show up.

Chrisyphus wrote

The process is extremely simple- easier IMO than the original stuff. Simply hand-thread the injection tool into the block, and then start turning the knob. The knurled knob is threaded onto the injector body; turning the knob will press the billet plunger into the injector body, which will then hydraulically [...]

Procedure is to install the front and rear oil seals before injecting the sealant.
Due to the thicker compound, did you inject the block using the new tool before or after the oil seal installation?

Chrisyphus wrote

100% correct across the board.

Me being a Honda guy, there's nothing better than Yamabond / HondaBond for sealing a bedplate.

charliev68 wrote

Picture of the tool doesn’t show up.

I thought it was only me!

omgzirra_exe wrote

Me being a Honda guy, there's nothing better than Yamabond / HondaBond for sealing a bedplate.

120%

charliev68 wrote

Picture of the tool doesn’t show up.

Sorry about that! Not sure what happened to the website's photos; I'll repair that in the morning.

For now, iPhone pics will do. These are all from before they were finished with ENP for corrosion resistance

charliev68 wrote

Procedure is to install the front and rear oil seals before injecting the sealant.
Due to the thicker compound, did you inject the block using the new tool before or after the oil seal installation?

We still install the main seals first and allow the new sealant to squeeze out the gap to create the best seal possible.

omgzirra_exe wrote

Me being a Honda guy, there's nothing better than Yamabond / HondaBond for sealing a bedplate.

This debate rages internally lol. All of us agree that all the aforementioned options are good. Either will work with our tool- those or the OE recommendation.