ACL rod bearings?

[groovetek]

Yes, HX shells. Been running Castrol 10W-60 TWS. Done 3 oil changes now over the 14k miles, although the last one was just last week before my track day.

https://www.youtube.com/playlist?lis..._eVOidaDCDucnD

Didn't push the car to its limits, but did constantly wring out the engine to near 8500rpm (Alpine MS tune, GTS DCT tune etc.)

Only car in my group with better straight line speed was my friend's lightly modded E60 M5. The white F80 LCI M3 was neck and neck with me all the way to 230kmh on the back straight

[r8ders]

Anyone have additional updates on people using the ACL bearings? Looking at getting the bearings done on my car but due to the supply issues with BE i'm looking at using the ACL's instead. Also, please let me know if you decided to run the "H", "HX", or the mix?
Thank you

[Johal E32]

Originally Posted by r8ders

Anyone have additional updates on people using the ACL bearings? Looking at getting the bearings done on my car but due to the supply issues with BE i'm looking at using the ACL's instead. Also, please let me know if you decided to run the "H", "HX", or the mix?
Thank you

I have 6,000 miles on the HX shells. Running Motul 10w60, no apparent issues. My car sees redline a few times a week.. It feels great.

PM me if you have any questions, I am located in the Bay Area as well.

[klo618]

Looking to change my rod bearings as well. It seems like there are mix reviews for bearing sizes on this thread. Can anyone update me on what to run? H, HX, or mix? I was leaning towards mix but it seems like you need to know what to do if you're doing mix. I am a complete beginner and dont know too much (planning to only providing bearings and bolts to my mechanic) so if anyone can guide me that would be great!

Thanks everyone- appreciate it.

[Assimilator1]

I'm planning to put ACLs in mine, with a bought mix and match from a forum seller here (I forget his name atm), was planning on doing it in April/May .

Oh btw, H's are similar to OEM clearances, so a bit on the tight side, HXs are a little bit over the extra clearance, so maybe a smidgen too much? (at the extremes of their clearances, but no reports of issues yet AFAIK) Hence mixing and matching, they need to be measured accurately btw.

[Scharbag]

Originally Posted by Assimilator1

I'm planning to put ACLs in mine, with a bought mix and match from a forum seller here (I forget his name atm), was planning on doing it in April/May .

Oh btw, H's are similar to OEM clearances, so a bit on the tight side, HXs are a little bit over the extra clearance, so maybe a smidgen too much? (at the extremes of their clearances, but no reports of issues yet AFAIK) Hence mixing and matching, they need to be measured accurately btw.

H are not close to OE 088/089 clearances and are better than 702/703 clearances as per the wiki. ACL-H shells are a great option as their minimum clearance is BMW's nominal for the S65.

As you state, mixing and matching requires accurate measurements. deansbimmer has a good post regarding this.

See available data attached.

Cheers,

[Assimilator1]

scharbag
The measurements of those ACL shells are not typical of the H rated shells specs, here are their specs (from ACL), also available from their pdf sheet.

References from my notes :-

ACLs own specs (ref posted email https://www.m3post.com/forums/showpo...8&postcount=36 & from Helmsman https://www.m3post.com/forums/showpo...postcount=1441)

ACL std H
Nominal Rod Bearing Clearance 0.0355 mm 0.00140 inch
Bearing Clearance Variance 0.013 - 0.058 mm 0.00051 - 0.00228 inch
(Redish Motorsport find they get ~0.05mm on plastigauges)

ACL std HX (extra clearance)
Nominal Rod Bearing Clearance 0.0615 mm 0.00242 inch
Bearing Clearance Variance 0.039 - 0.084 mm 0.00153 - 0.00331 inch

As you can see H shells at nominal clearances are close to OEM specs, this has been pointed out before (by Helmsman IIRC) to the BE guy (sorry, forgot his name), but he never replied to the post.
It would seem the shells he received had clearances near the larger end for these shells.

[Green-Eggs]

Originally Posted by Assimilator1

scharbag
The measurements of those ACL shells are not typical of the H rated shells specs, here are their specs (from ACL), also available from their pdf sheet.

References from my notes :-

ACLs own specs (ref posted email https://www.m3post.com/forums/showpo...8&postcount=36 & from Helmsman https://www.m3post.com/forums/showpo...postcount=1441)

ACL std H
Nominal Rod Bearing Clearance 0.0355 mm 0.00140 inch
Bearing Clearance Variance 0.013 - 0.058 mm 0.00051 - 0.00228 inch
(Redish Motorsport find they get ~0.05mm on plastigauges)

ACL std HX (extra clearance)
Nominal Rod Bearing Clearance 0.0615 mm 0.00242 inch
Bearing Clearance Variance 0.039 - 0.084 mm 0.00153 - 0.00331 inch

As you can see H shells at nominal clearances are close to OEM specs, this has been pointed out before (by Helmsman IIRC) to the BE guy (sorry, forgot his name), but he never replied to the post.
It would seem the shells he received had clearances near the larger end for these shells.

Bert doesn't have an account here, so he can't really respond. There is a difference between paper specs and real world measurements. The data posted by Sharbag came from real world measurements.

[Scharbag]

Originally Posted by Green-Eggs

Bert doesn't have an account here, so he can't really respond. There is a difference between paper specs and real world measurements. The data posted by Sharbag came from real world measurements.

I also trust actual data more than paper specs. Just ask Mazda how that worked out on the RX-8...

Given the real world info we have, the H shells are a good fit if you cannot find BE bearings.

And I will never understand why people choose to purchase bearings that are not binned and matched when that option exists. Yes, I know there is a shortage, but plan ahead and use the right parts if possible. IF you do not, you are rolling the dice with respect to tolerance. It is just statistics. Unless you measure (which requires engine out to do right), you are accepting increased risk. Now, if you actually measure and bin the ACL-H/ACL-HX, then your are controlling that variable and mitigating the risk. To do this properly, you would really need to buy a LOT of shells (thousands) or you would likely throw away a lot of sets trying to match the tolerance BE offers. Again, statistics is a harsh mistress.

ACL, Clevite, King and Glycol all make great quality bearings. That has never been the root concern. Clearance is. If you do not believe that clearance is an issue, then do not change your bearings.

On another note, I read an interesting post that mentioned that NASCAR uses Clevite-77 bearings (same spec as BE) and they pay $4,000.00 per hand-matched set. So, BE is a FANTASTIC deal for a hand-matched set of high quality bearings for a V8.

Cheers,

[Assimilator1]

Originally Posted by Green-Eggs

Bert doesn't have an account here, so he can't really respond. There is a difference between paper specs and real world measurements. The data posted by Sharbag came from real world measurements.

Actually I was thinking of you , I thought you were the same person anyway?

Anyhow, as (IIRC) Helmsman has mentioned/asked you before, and as I will now again.
We are not calling into question your measurements of actual shells (thank you very much for your/Bert's work on this btw), but as far as we know (according to the BE wiki itself) you measured only 1 set of each H and HX ACL shells, now I totally understand why, buying even say 6 sets of each would be really expensive and not in your interest to then sell on a competitors shells. But nonetheless it remains unrepresentative that you state these measurements are relevant to all H and HX ACL shells.
I can't remember for the HX shells, but for the H shells you may have had an outlier set (in a good way on this set).

So unless someone can post data* showing that the ACL H shells are generally giving more clearance than the OEM shells, data from ACL themselves shows nominally otherwise.

*The closest I've seen on that to date is by Redish Motorsport here in the UK who find they get ~0.05mm on plastigauges (on I think a few dozen engines IIRC).
But I've seen it stated many times by others that pastigauges only gives you an approximate idea of clearances, so is it accurate enough? If I'm right on a few dozen (I'll see if I can corroborate that), is that enough of a data set to be reasonable sure that if I get H shells I'll end up with ~0.05mm on plastigauges?

Scharbag
As I said to you before , BE bearings are much more expensive here in the UK (and I think Europe).

Now, if you actually measure and bin the ACL-H/ACL-HX, then your are controlling that variable and mitigating the risk

This is the service that mpowermotorsports [allegedly] offered, I was about to order some from him, when 1. his wife was involved in a serious accident, and 2. lockdown occurred .
I'm about to contact him again to see if he can still do that.

[Kelse92]

Bumping up an old thread. Anyone been running Blackstone reports on cars with ACL bearings in here? I have been every other oil change and have been starting to see lead/copper in the reports.. just curious if anyone else has seen the same or if it might be fuel related.

[tdott]

Originally Posted by Kelse92

Bumping up an old thread. Anyone been running Blackstone reports on cars with ACL bearings in here? I have been every other oil change and have been starting to see lead/copper in the reports.. just curious if anyone else has seen the same or if it might be fuel related.

Which ACL bearings did you go with?

If H, then perhaps you got the tighter end of the tolerance stack and are seeing wear like an OEM bearing would.

[ha9981]

I'll try to simplify this a bit:

Go with any option except OE. Even if you go OE it's okay, you can replace them again at a safe interval depending on how the last ones came out.

If you are on an open budget go BE, as they are great. Or else get ACL mixed shells. If you want to go either HX and H that is fine too. But having BE and ACL mixed shell clearance is smarter as we have oil flow analysis on the clearance, courtesy of BE. So if you got the cash support BE.

In regards to bin approach controlling one variable. It's marketing. If you didn't measure your foot size and you are trying to get a very exact size of shoe, it's being silly. If you really cared you'd measure your feet and get the right size for each foot. So if you really think it's important to your application then take out your crankshaft and rods and get measuring. It will be very expensive as that is an engine out procedure.

For the whole NASCAR stuff, it's clever marketing, initially I fell for it too. A race engine is designed to run for x hours and then rebuilt. Do you really think that largely translates to your use case?

Most of us here are big time car guys, that also means we get taxed for it, often we pay extra for marketing. So no disrespect to others as often I get caught up in marketing too.

[Scharbag]

Originally Posted by ha9981

I'll try to simplify this a bit:

Go with any option except OE. Even if you go OE it's okay, you can replace them again at a safe interval depending on how the last ones came out.

If you are on an open budget go BE, as they are great. Or else get ACL mixed shells. If you want to go either HX and H that is fine too. But having BE and ACL mixed shell clearance is smarter as we have oil flow analysis on the clearance, courtesy of BE. So if you got the cash support BE.

In regards to bin approach controlling one variable. It's marketing. If you didn't measure your foot size and you are trying to get a very exact size of shoe, it's being silly. If you really cared you'd measure your feet and get the right size for each foot. So if you really think it's important to your application then take out your crankshaft and rods and get measuring. It will be very expensive as that is an engine out procedure.

For the whole NASCAR stuff, it's clever marketing, initially I fell for it too. A race engine is designed to run for x hours and then rebuilt. Do you really think that largely translates to your use case?

Most of us here are big time car guys, that also means we get taxed for it, often we pay extra for marketing. So no disrespect to others as often I get caught up in marketing too.

Wow...

Binning is a marketing gimmick? Comparing hydrodynamic bearings to shoe size?

Good grief.

I will choose to listen to the actual engine builders that know what they are talking about.

SMH.

[ha9981]

Originally Posted by Scharbag

Wow...

Binning is a marketing gimmick? Comparing hydrodynamic bearings to shoe size?

Good grief.

I will choose to listen to the actual engine builders that know what they are talking about.

SMH.

Go speak with Lang Racing, they build lots of engines. They hold the same opinion that bin approach is of little value when you are doing it without having your journals measured.

If Lang is selling mixed shells without bin method then I'm confident that my logic checks out. This forum has some smart people but they suffer from holier than thou. "I shall get zero variance and nothing less"

Great you have the money to do it, then do it. You want to do 1k mile oil changes, do it. Don't make it seem like a crime if someone is not as extreme as you maybe.

I can play the same game. I would never install bearings without measuring the journal. WOW. What kind of engine builder would ever do that? You bought a BMW stop being cheap, pull the engine out and get it done properly.

I know we are rational and smarter than that

[ha9981]

Pulled from M5 board

Question:
"Question for @andrewlang do you guys just mix and match bearings or are there some measurements and hand-selection involved (i.e. what BE does)?"

Andrew Lang:
"We haven't found it to be necessary to do that. The bearings we measured from multiple boxes seemed to be very consistent in thickness from ACL, meaning you're going to be getting journal to journal variances within a couple of tenths.

I feel the need to further point out that there are a few other variables involved in rod bearing clearances than simply the thickness of rod bearing shells. Nobody, including my own shop, ever bothers to spend the time measuring rod journal dimensions on these cars when they are replacing rod bearings. Theoretically the ideal way to do this job would be to measure every single bearing thickness in the package you receive and sort them from smallest to biggest. You would measure every rod journal dimension and match the thinner bearing shells with the larger rod journals to obtain optimal clearance on each journal. Of course nobody bothers to do that because none of us feel that the time would be worth the tighter tolerance from one journal to another.

But, for anyone who has built these engines and read BMW procedures this is exactly what BMW is asking us to do on main bearing journals and even on some of the more modern BMW engine rod journals. They have different shell thicknesses you can choose from to obtain optimal bearing clearances from journal to journal.

It's nice that some bearing distributors sort bearing shells by thickness for us. But I think we can rely on the bearing manufacturer to deliver shells that are within acceptable tolerances.

More information than you're asking for but just something to think about."

[Green-Eggs]

Originally Posted by ha9981

Go speak with Lang Racing, they build lots of engines. They hold the same opinion that bin approach is of little value when you are doing it without having your journals measured.

I disagree. Binning removes one variable from the clearance equation. Why would you want to allow multiple unconstrained variables in a clearance equation when you can eliminate by constraining one of them? The goal isn't zero variance, as you stated later, the goal is to eliminate one variable from the clearance equation.

Originally Posted by ha9981

Pulled from M5 board

Question:
"Question for @andrewlang do you guys just mix and match bearings or are there some measurements and hand-selection involved (i.e. what BE does)?"

Andrew Lang:
"We haven't found it to be necessary to do that. The bearings we measured from multiple boxes seemed to be very consistent in thickness from ACL, meaning you're going to be getting journal to journal variances within a couple of tenths.

I feel the need to further point out that there are a few other variables involved in rod bearing clearances than simply the thickness of rod bearing shells. Nobody, including my own shop, ever bothers to spend the time measuring rod journal dimensions on these cars when they are replacing rod bearings. Theoretically the ideal way to do this job would be to measure every single bearing thickness in the package you receive and sort them from smallest to biggest. You would measure every rod journal dimension and match the thinner bearing shells with the larger rod journals to obtain optimal clearance on each journal. Of course nobody bothers to do that because none of us feel that the time would be worth the tighter tolerance from one journal to another.

But, for anyone who has built these engines and read BMW procedures this is exactly what BMW is asking us to do on main bearing journals and even on some of the more modern BMW engine rod journals. They have different shell thicknesses you can choose from to obtain optimal bearing clearances from journal to journal.

It's nice that some bearing distributors sort bearing shells by thickness for us. But I think we can rely on the bearing manufacturer to deliver shells that are within acceptable tolerances.

More information than you're asking for but just something to think about."

A lot of people on FB think that Lang measures every shell and offers matched sets -- BE Bearing style. This post definitely clarifies that is not the case.

Having watched Bert measure many thousands of shell thicknesses, and seen how many he throws away (literally), I can tell you that the shell thickness variance is more than you think. The specs say +/- 1.5/10ths, but in reality they can go outside of these specs about 1% of the time. Sometimes they go dangerously outside of these specs. Eliminating this variable is achieved by measuring and binning.

In the set of ACL shells measured by BE, the HX shell thickness was very consistent, but the H shell thickness was much less so. There were 2.5/10ths variance in the H shells, but only 1/10th in the HX shells.

Removing this variable has benefit, even if measuring the journals is very difficult when the engine is still assembled, and when you have no control over the remaining variables in the clearance equation.

[Helmsman]

Originally Posted by Green-Eggs

In the set of ACL shells measured by BE, the HX shell thickness was very consistent, but the H shell thickness was much less so. There were 2.5/10ths variance in the H shells, but only 1/10th in the HX shells.

Cheers Green-Eggs. Regarding your stated Nominal shell thickness/clearance I understand it makes sence and is quite possible on your own product, owning the spec and after thousands produced.

But in the case of ACL and your other competitors, I wonder how you establish Nominal after measured a set or two?

Thanks

[Bigtriece]

Wow,

This thread has given me more anxiety than I have ever felt in my life ha!

Honestly, without a straight up comparison on the exact same crank under the exact same conditions how can anyone even argue all this? BE shells have better variance but are never in stock. ACL have a little more variance but are readily available.

I'd also like to see a daily driven 50-100k mile set of BE and a daily driven 50-100k mile set of ACL STD on on the same mile engines from the start.

From reading all this it really seems like the ONLY way to have a perfect situation is to measure the crank and place the perfect shell for that perfect spot on the crank. Who are we kidding with this because anyone willing to go that far won't be trusting ANY bearing past 100k or X number of track days.

Getting ACL STD installed next week because I can't get BE and my 2010 has 102k. It'll get new bearings in 30-40k anyways. Regardless of if I had BE in there or not because it's not a daily and it's also not a dedicated track car.

[Kelse92]

Originally Posted by ha9981

If you are on an open budget go BE, as they are great. Or else get ACL mixed shells. If you want to go either HX and H that is fine too. But having BE and ACL mixed shell clearance is smarter as we have oil flow analysis on the clearance, courtesy of BE. So if you got the cash support BE.

The problem is not with cash. The problem is with BE availability...

[DRLane]

Another bearing thread with new M owners regurgitating their "hearsay research". Yes, that includes from vendors and or your local mechanics.

New owners be aware much of this advice comes from owners that'll be off the platform in less than 2 years... Scharbag is an asset for piping in regularly to remind the new owners of the available research. It's there, read it!

BE bearings aren't impossible to get, but they are challenging if you wait until you need them. If you believe the research, buy a set or get on a waitlist now. They'll be available before you realize and you can schedule the service at your leisure.

[tdott]

Originally Posted by Kelse92

The problem is not with cash. The problem is with BE availability...

Don't wait until there is a pandemic and a shortage to buy them