Oil Weight for built engine/Ideal oil pressures

[B320i]

Originally Posted By: OVERKILL
The flaw in your logic is you think I'm making an argument, I'm not. This is how the industry works. Performance engines; engines that develop more power than their non-performance oriented siblings, generally spec heavier oil, sometimes have increased sump volume and usually have increased oil cooling.

The anecdote in this case is BMW spec'ing the Castrol 10w60 for a series of engine due to issues with the usual "approved" 5w30 and premature failure of bearings.

In any case; this was the manufacturer recognising an inherent issue of the series of motor(s) and altering their recommendation to reduce the incidence of failure. Newer vehicles may not require the same oil due to alteration to their design.

The fact remains however, that BMW has for a long time specified heavier oils that are more resistant to degradation (i.e. shear) in order to suit higher performance and longer drain intervals. There is probably more to it, but that's the very short explanation.

 

[Only1Hockeytown]

Originally Posted By: BrocLuno
With the clearances you provided I'd start at 40 grade oil. Mono, multi, whatever floats your boat. Then I'd be looking for bearing metal indicators in UOA's or any sign of non-magnetic sheen in the oil on drain. I'd keep the change intervals short, like 2,500 miles, until I had a lab tell me that all is well.

5W-40 ~ 15W-40 makes no difference to me. It's the hot viscosity I'm concerned about.

How is this motor at aerating oil in the sump? What have other machinists of similar built engine indicated works best?

Is this motor going to see short bursts of power like in drag racing, or hours in the high HP zone like track days?


I think I'll go with the 0w-40 and see how its comparing. I'll get my current 5w-30 tested as well. Currently it's my daily and I don't beat on it too much.

For the record my oil temp usually peaks at around 210F if it's a very hot day and I'm driving a little harder. Typically it's around 190-200F. I do have an aftermarket oil cooler but it's only slightly larger than stock if at all.

 

[BrocLuno]

All good, sounds like you are on track

Adding a smidge to the overall oil capacity does not hurt. If you can fit a larger filter, you'll pick up both filtration media area and oil capacity - both are good things

Most Napa Auto Parts stores have cross reference guide with gasket base, relief values, thread pitch/dia, and can dimensions. So you can work up what might fit right at the counter.

In my experience, Napa Gold (WIX) are very good filters. Buy one after they do the look-up to compare to say Fram from W-M. Get them to give you the Fram numbers and the Baldwin numbers for your notebook, maybe even the Mann numbers (for OEM fitment and oversized)

Oh, and get a magnetic drain plug. When you pull it see what's on there. If not much you are golden. If gritty, you have an issue coming at you fast ...

 

[OVERKILL]

Originally Posted By: Only1Hockeytown
Originally Posted By: BrocLuno
With the clearances you provided I'd start at 40 grade oil. Mono, multi, whatever floats your boat. Then I'd be looking for bearing metal indicators in UOA's or any sign of non-magnetic sheen in the oil on drain. I'd keep the change intervals short, like 2,500 miles, until I had a lab tell me that all is well.

5W-40 ~ 15W-40 makes no difference to me. It's the hot viscosity I'm concerned about.

How is this motor at aerating oil in the sump? What have other machinists of similar built engine indicated works best?

Is this motor going to see short bursts of power like in drag racing, or hours in the high HP zone like track days?


I think I'll go with the 0w-40 and see how its comparing. I'll get my current 5w-30 tested as well. Currently it's my daily and I don't beat on it too much.

For the record my oil temp usually peaks at around 210F if it's a very hot day and I'm driving a little harder. Typically it's around 190-200F. I do have an aftermarket oil cooler but it's only slightly larger than stock if at all.


Thank you for the additional information. How much power are you making above stock? Have you had it on a dyno? What kind of tune are you running? You will probably find that it is only when really pushing it that you'll drive up oil temperatures beyond coolant if you are using a heat exchanger style cooler, which is what it sounds like, since oil temp sounds like it is following coolant temp. This was the case on my M5 and is as well as our two Chargers.

This being the case, in terms of daily driver usage, the slightly higher HTHS of the 0w-40 provides a greater buffer for increased bearing loads, which may or may not really be necessary depending on how much reserve existed in the OEM setup. It becomes more relevant if you were really pushing it and driving oil temps up further, outside of the range the engine would experience under stock power levels. Ultimately there's nothing wrong with erring on the side of caution in terms of viscosity reserve, which is what this recommendation is based on.

 

[Ramblejam]

Originally Posted By: OVERKILL
The flaw in your logic is you think I'm making an argument, I'm not.

Originally Posted By: OVERKILL
few key members


I figured as much, but glad you outright admitted it; generalized suggestions from someone who thinks of himself as a very important, key figure in internet forum land.

Originally Posted By: Only1Hockeytown
I think I'll go with the 0w-40 and see how its comparing. I'll get my current 5w-30 tested as well.

 

[OVERKILL]

Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
The flaw in your logic is you think I'm making an argument, I'm not.

Originally Posted By: OVERKILL
few key members


I figured as much, but glad you outright admitted it; generalized suggestions from someone who thinks of himself as a very important, key figure in internet forum land.


I wasn't including myself in that list actually, I was thinking more about Shannow and CATERHAM, particularly since you mentioned CATERHAM 3x in the thread and brought up their ongoing rivalry. Glad to see that you came back to troll some more though

I don't know what's more laughable, the fact that you think that drawing attention to your intentional trolling for reaction from certain people shows those people as self-absorbed, or that you think that nobody would pick-up on that being your intention

Originally Posted By: Ramblejam

I'll entertain it for a little while (this evening). Then, I'm out, and as I said, you guys can continue the back-and-forth for years to come.


Entertain is the key here. Baiting people into an argument because you were bored and figured it would be fun to rustle some feathers. Then trying to turn it around and paint those people, who were actually trying to help the OP, as egotistical defectives, completely ignoring the rather deplorable motivation that spurred that discourse in the first place. Classic.

Bravo again, and thanks for the encore post.

 

[Ramblejam]

Excellent bloviating. Bravo.

 

[OVERKILL]

Originally Posted By: Ramblejam
Excellent bloviating. Bravo.


Always a pleasure. Let's be sure to do this again soon.

 

[Ramblejam]

Hopefully never again; the pleasure has been all yours.

 

[OVERKILL]

Originally Posted By: Ramblejam
Hopefully never again; the pleasure has been all yours.


LOL! Doubtful, I'm not the one claiming entertainment here

Anyways, enjoy the rest of your weekend.

 

[Ramblejam]

Originally Posted By: OVERKILL
Anyways, enjoy the rest of your weekend.

 

[OVERKILL]

 

[BrocLuno]

There is one place where blown motors can get into trouble (either driven or turbo'd) and that is when the engine is at lowish RPM and the boost comes in big time. At that point they can develop very high sustained rod bearing loads and thin oils will be gone instantly. That is why many folks running serious blown engines have always relied on higher viscosity for the film strength/depth.

If your turbo take a bit to spool-up and the engine is climbing anyway so that you are in mid to upper RPM range when it hits, it's not as big a deal as the pressure/duration envelope has changed...

 

[zeng]

Big thanks to all above for sharing their respective knowledge and interpretations.

Had been reading and 'digesting' every single word said here.