S65 Engine Main Bearing Service, Documented

SYT_Shadow wrote

great information deansbimmer, thank you so much

if pbonsalb wants to mess around with this during winter I may get involved

I am tempted. I just moved within Concord, NH and am renovating my barn and am not sure when it will be done. But if I can finish it and can schedule a free long weekend or two, I would be up for it especially if I had a skilled DIYer or two to help like SYT_Shadow and his brother.

pbonsalb wrote

I am tempted. I just moved within Concord, NH and am renovating my barn and am not sure when it will be done. But if I can finish it and can schedule a free long weekend or two, I would be up for it especially if I had a skilled DIYer or two to help like SYT_Shadow and his brother.

Let me know. You're an hour away.

Ok. It would be awesome to have a pro help with the critical parts!

pbonsalb wrote

I am tempted. I just moved within Concord, NH and am renovating my barn and am not sure when it will be done. But if I can finish it and can schedule a free long weekend or two, I would be up for it especially if I had a skilled DIYer or two to help like SYT_Shadow and his brother.

we're up for it, just let us know with some time so we can plan for it!

jcolley it would be great to meet in person as well

pbonsalb wrote

Ok. It would be awesome to have a pro help with the critical parts!

SYT_Shadow wrote

we're up for it, just let us know with some time so we can plan for it!

jcolley it would be great to meet in person as well

I'm game, just hopefully after the end of July. Let me know what to bring.

We are thinking sometime this winter.

pbonsalb wrote

We are thinking sometime this winter.

Guys if at all possible I would like to participate. Would love to help in anyway I can.

Dave

Ok. Maybe we can plan later this year. Or maybe someone else will DIY this first. But it looks like we have great potential here in the N.H area with an experienced S65/85 builder like jcolley offering to help us DIYers avoid doing something stupid.

I’ve done business with deansbimmer. He’s worthy.

Great job! I can't imagine I ever take this on, but if I did, this is all I would need.

How necessary is this preventive maintenance? If it's that prevalent, why hasn't BMW issued a recall? I've heard they've replaced entire engines because of this issue in the past.

I fashioned myself a DIY, until I read through the steps. Would take me all of 5 seconds to pay DB to do it for me. Way out of my wheelhouse of skill.

Wow, that's some seriously impressive detail work. If I lived closer, I'd have no problem taking my car to DB for any work I needed to have done.

And with that....I think it's time to now sell the car.

i am already going though logistics in my head to send out my motor to DB when the time comes. I do not plan to ditch this chassis anytime soon, no turbo cars for me thank you very much.

Just watched a video of Matt's safari 911 engine rebuild. Can't believe the difference of bearing condition between my S65 and a thrashed 911 with 94k miles.
Worried how much time I have left on my main as I had several rod bearings showing copper layer...

At 3:11.

kyrix1st wrote

Just watched a video of Matt's safari 911 engine rebuild. Can't believe the difference of bearing condition between my S65 and a thrashed 911 with 94k miles.
Worried how much time I have left on my main as I had several rod bearings showing copper layer...

Cool video. Yes, that's what we wish our bearings would look like, but unfortunately that's not what we typically see. Our mains are almost always worn through the babbit layer in places. Luckily they wear slower than rod bearings so unless the engine was built a little tight from the factory, they should usually last the practical life of the engine.

To anyone following this topic, KING has released main bearings for their 2019 catalog. They're not yet available but if they're anything like their newly released rod bearings, they may not be a drop in replacement. (Their rod bearings require honed rods). I've got sets on order and will update once they start shipping.

deansbimmer wrote

To anyone following this topic, KING has released main bearings for their 2019 catalog. They're not yet available but if they're anything like their newly released rod bearings, they may not be a drop in replacement. (Their rod bearings require honed rods). I've got sets on order and will update once they start shipping.

That's a good thing. It makes line honing a block less work if there are thicker bearings available. No decking the block/bedplate, milling a new sealant channel, boring radial seal ODs, etc.

jcolley wrote

That's a good thing. It makes line honing a block less work if there are thicker bearings available. No decking the block/bedplate, milling a new sealant channel, boring radial seal ODs, etc.

Absolutely agree. It gives us more options. Also great for those who need to replace their bed plate and line hone mismatched units.

deansbimmer wrote

To anyone following this topic, KING has released main bearings for their 2019 catalog. They're not yet available but if they're anything like their newly released rod bearings, they may not be a drop in replacement. (Their rod bearings require honed rods). I've got sets on order and will update once they start shipping.

hi,

I cannot thank you enough for your contributions to this forum. This is of a real help. There are many people here who are only after profits from these forums and not really contribute much. I cannot thank you enough...
i am in process of rebuilding my S85 and these post is immensely helpful.
I have a question regarding main bearings...i need to replace the main bearings
and tempted to go for Kings because apparently is not need to match them...they are just drop ins... what do you think about it?
If I had to go OEM, considering the crank would be different but same bedplate... would I need to go for "R" mains? In TIS is a big ambiguous as I think when they debate the scenario "used bedplate used crank" they refer
to the same bedplate/crank combination that was originally installed.
What about my scenario where its the same bedplate but different-used crank? do i need to go by the GYV colors or go for "R" if going OEM?

Regards,

Any bearing you go with needs to be measured and assessed for suitability. King's set is no different. See first post- BE/rcollins provides a crankshaft bearing chart condensed from BMW information that helps identify which bearings you should use depending on actual journal measurements. If you've replaced the crankshaft then you can't go by the identifiers on the parts.

Any replacement main bearing you purchase from BMW is going to be identified "R".

If you're not sure or don't have the micrometers and bore gauges to identify what you need, I'd suggest contacting a qualified shop near you for assistance.

WOW, the level of detail is fantastic! Nothing I would ever be comfortable with doing but hey, never hurts to look at the process. Thank you for this!