Official ACL Rod Bearing Measurements

[Helmsman]

Originally Posted by deansbimmer

BE is a relatively small operation. The more business we can give them the more sets they can order at a time until availability is no longer an issue. They've been near doubling each of their orders with Clevite...

Additionally, just because their website says unavailable doesn't mean their listed vendors don't have any. We've had them in stock all this time but only one customer contacted us for purchase.

Very nice to keep stock mate and even more so when delivery is tight. Wasn't the case with the shops over here but is what it is.

Still interesting to understand BE's comment that the ACL shell is too open. Yes 0.073mm seem on the high side - even for a layman who only understand how to read data - but again ACL has been around for a long time so puzzles me that they should bring out a product that potentially brings issues.
Believe ACL's target was 702/703 OEM clearance with HX adding the 0.025mm which would end up on 0.06 isch all according to Clevite's formula.
Not arguing here btw, just curious to learn. Let's see if BE chimes in.

Cheers

[groovetek]

Ha, just happened to come back here as a mate is looking to get an E60 M5 and looks like incidentally there have been some updates, and recommendations that HX is too much clearance...

So I've done over 7000kms on my HX now... all seems well, still on 10W-60 Castrol TWS.

Also been running 8500rpm redline with the AlpineMS tune, everything seems/feels strong.

Should I be concerned?

Does anyone have a link to the same style of measurements of stock 088/089 and 702/703 bearings?

[Helmsman]

Originally Posted by groovetek

Ha, just happened to come back here as a mate is looking to get an E60 M5 and looks like incidentally there have been some updates, and recommendations that HX is too much clearance...

So I've done over 7000kms on my HX now... all seems well, still on 10W-60 Castrol TWS.

Also been running 8500rpm redline with the AlpineMS tune, everything seems/feels strong.

Should I be concerned?

Does anyone have a link to the same style of measurements of stock 088/089 and 702/703 bearings?

All good here as well with HX inside. Daily driving with 10w60 in Nordic winter. We'll see if she blows coming Summer with spirited drive and higher temps...

Heres BEs measurement, to my knowledge the only one comparing data: http://wiki.rcollins.org/core/index.php/Engine_Specs_-_S65_Rod_Bearings

[Helmsman]

AutoTalent, not dicking around but bit curious to understand how you come to ACL HX 0.0610 – 0.0838mm clearance variance.
ACL’ own spec says 0.039mm (shaft max of 51.991, housing min of 56.000, bearing wall max at 1.985. ie 56.000-51.991-2x1.985=.039mm).
You seem to be using a slightly different shaft spec which would end up on 56.000 - 51.9887 – 2x1.985 = 0.0413, no?

While we’re at it I’m curious about BE’s spec here as well that from what I understand says clearance variance 0.0456 – 0.0711mm.
Using the shaft dimensions on your page the way I calculate would give:
Max clearance: 56.013 – 51.9786 – 2x1.9812 = 0.0721mm
Min clearance: 56.000 – 51.9887 – 2x1.9939 = 0.0234mm

Edit: And assuming I get the numbers right that would mean if there is something called Nominal clearance, ACL would end up on 0.084-0.039/2 = 0.0225 => 0.084-0.0225 = 0.0615mm clearance. I.e. FWIW right on target using Clevite's rule of thumb.

While BE's Nominal would end up on 0.0721-0.0234/2=0.02435 => 0.0721-0.02435= 0.04775mm clearance.

Please bare with me if I completely missunderstand something here, but my basic wondering is how the variance can be that “tight” with shaft and housing tolerance combined doesn’t seem to be.

Thanks
Nik

[Assimilator1]

I'd be interested to know the answers to the above too ......

Although I think I can answer one of them (bar the ~0.023mm differences in journal size stats), they measured one set, so it would seem this one set is hitting ACL's tolerance range from the mid to upper end.

[costa84]

bringing the old thread up. any update after installing the 8B1580HX-STD bearings?

[Helmsman]

Originally Posted by costa84

bringing the old thread up. any update after installing the 8B1580HX-STD bearings?

All good here after 3.5 years and 16k miles. Crossing fingers and drive on with a smile.
Ps. And obviously stayed with thick and nice 10W60 to fill up the extended clearance.

[Johal E32]

Originally Posted by costa84

bringing the old thread up. any update after installing the 8B1580HX-STD bearings?

19.7K miles and 2 years on my HX bearings.

I have performed two Blackstone oil analysis tests and they both came back clean.

[clubsport.m3]

Thanks for updating this guys, thats great. Im going with HX for my tracktool and will report back after some torture on the Nurburgring

[Green-Eggs]

Originally Posted by clubsport.m3

Thanks for updating this guys, thats great. Im going with HX for my tracktool and will report back after some torture on the Nurburgring

Too little and too much clearance are both bad.

[Assimilator1]

Yea, and HX + regular track use, meaning higher oil temps (so thinner oil for greater time) and for longer periods doesn't sound like a good idea to me.

I would go for mixed and measured ACL bearings if I were you, Mporium (Deansbimmer) sent a M&M set to me here in the UK, so I'm sure he could send some to the NL.