Just bought a set of VAC/CALICO rod bearings

[Duk996]

Originally Posted by doogee

Certainly doesn't "hurt".

I think it's easier to use oil. Pull the fuel pump fuse and let it crank for a while before first start up.

More than 1 way to skin a cat. Pull the plugs so no compression and it's even better.

Btw, what do our cars do when it cranks and no starts? It must stop after so many seconds....does it throw a fault?

[deansbimmer]

Use assembly lube on the bearings it protects better than plain engine oil. Don't pull the fuse and just let it crank. That can do more harm than good and slings off any of the lube you put on the bearings in the first place. Let the engine start and idle. It only takes 2-4 seconds for the engine to build full oil pressure.

If you lube the rod bearings during the job then as far as the engine is concerned it's no different than an oil change on the first startup. There's zero reason to keep it from starting.

[doogee]

Originally Posted by deansbimmer

Don't pull the fuse and just let it crank. That can do more harm than good and slings off any of the lube you put on the bearings in the first place.

Uhhh what?

With this logic, you're basically saying doing a compression test is harmful.

You do realize the whole idea is the build some oil pressure without load. The oil doesn't "fling off".

To be completely realistic, assembly lube AND cranking without firing the motor ahead of time are not necessary.


This is standard practice by most car brands in any repair procedures and also used by just about anyone involved in racing.

It's not harmful. That is complete non sense. You sounded very competent to me on here until now.


I'm done trying to help out on here

[Duk996]

Originally Posted by doogee

Uhhh what?

With this logic, you're basically saying doing a compression test is harmful.

You do realize the whole idea is the build some oil pressure without load. The oil doesn't "fling off".

To be completely realistic, assembly lube AND cranking without firing the motor ahead of time are not necessary.


This is standard practice by most car brands in any repair procedures and also used by just about anyone involved in racing.

It's not harmful. That is complete non sense. You sounded very competent to me on here until now.


I'm done trying to help out on here

I'm not sure what Dean means either but let's give him the benefit of the doubt. He may think there aren't enough revs without starting it to move a meaningful amount of oil, not sure. I think we can all agree the goal is to avoid revs without parts being lubed.

[deansbimmer]

Admittedly in this application it probably is a difference of splitting hairs. If any oil is on the bearing it should be fine.

As Duk figured, at crank RPM the engine will not achieve the same pressure as it would at idle. There will be flow which should be enough to get to the bearings after a few seconds, but it becomes a question of whether it's really necessary. BMW does not tell us in TIS to crank the engine without starting after this job.

I am not debating that after a full rebuild or job where the entire oil system is void of oil that it would be beneficial to crank the engine without starting. After a RB job oil still remains in the main circuits thus pressure would be achieved in only a second or two of the start/run process. Assembly lube is a much thicker, slicker, and pressure resistant lubricant than 10w60, but the majority of it can be wiped off after so much cranking and you replace its benefits with the benefits of regular oil. Seeing that BMW leaves us without direct instruction, it's my professional opinion that on this job it would be more beneficial to let the assembly lube do its job (which it does quite well on bearings) and to let the full oil pressure come in after starting, than it would be to crank the engine for an indeterminate amount of time, potentially wiping off most of the assembly lube before the oil takes over.

I'm never on here to aggravate other users who have first hand experience and have their own method of doing things. But I will chime in if there is another school of thought that works. I'm sorry if it came off as the one-and-only method. I don't have enough time to write about every angle I'm considering when I make such statements. I've got my head in two S65 builds I'm working on right now and I get passionate about the details sometimes.

[jcolley]

Originally Posted by jcolley

When I ordered a a few sets of rod bearings last year from VAC, I inquired about the mains as well as I have two very unique motor builds going together. i was told they are all "greens" which makes logical sense to me to pick the middle target.

I'm guessing in their mind if someone is looking for a higher performance bearing than OEM, the block and bedplate would line bored to spec anyway with a custom crank and clearance verified via bore gage and mic anyway.

I was just going back through emails with VAC and ran across the email we discussed mains in.

***I stated incorrectly above: The coated main bearings VAC sells are Yellows***

I'm ordering a couple to put in a bedplate and measure what that actually comes out to once torqued down.