BMW M5 Forum and M6 Forums banner

1 - 20 of 66 Posts

·
Registered
Joined
·
74 Posts
Discussion Starter #1 (Edited)
I just finished doing bearings/VANOS line/motor mounts etc. on my 2007 M5 with 104k mi. Sorry for the image links, they don't seem to render inline.


http://e36-electronic.com/photos/M5/rb1.jpg

My bearings looked better than expected for 104k mi:


http://e36-electronic.com/photos/M5/rb4.jpg

I went with custom ACL bearings from Lang Racing ("customized for .0023" to .0025" Bearing Clearance"):



http://e36-electronic.com/photos/M5/rb2.jpg
http://e36-electronic.com/photos/M5/rb3.jpg

Plastigauge looked good:


http://e36-electronic.com/photos/M5/rb6.jpg


http://e36-electronic.com/photos/M5/rb7.jpg

I got the car back together yesterday and everything is fine so far.
 

·
Registered
Joined
·
341 Posts
another win for ACL! nice work.

my car's also running like champ with those ACL bearings. hit 170mph yesterday with ease. i like that ACL has even more clearance than BE. it's actually the perfect amount i would gap the rod bearing if i were building any other engine. BE is still little too tight imho!
 

·
Registered
Joined
·
341 Posts
btw whoever that sold you the bearings put those bottom and top stickers on themselves lol. it's little cheeky imho. unless you did it yourself.

i asked ACL directly, and they told me they do not separate top and bottom shells.

that's the only improvement i wish ACL make for my next set from them at 150k miles.
 

·
Registered
Joined
·
74 Posts
Discussion Starter #4 (Edited)
another win for ACL! nice work.

my car's also running like champ with those ACL bearings. hit 170mph yesterday with ease. i like that ACL has even more clearance than BE. it's actually the perfect amount i would gap the rod bearing if i were building any other engine. BE is still little too tight imho!
btw whoever that sold you the bearings put those bottom and top stickers on themselves lol. it's little cheeky imho. unless you did it yourself.

i asked ACL directly, and they told me they do not separate top and bottom shells.

that's the only improvement i wish ACL make for my next set from them at 150k miles.
The bearings I bought are not one of the regular 2 flavors of ACL, they are customized for .0023" to .0025" by Lang, essentially the same clearance as BE.
 

·
Registered
Joined
·
111 Posts
I just finished doing bearings/VANOS line/motor mounts etc. on my 2007 M5 with 104k mi. Sorry for the image links, they don't seem to render inline.


http://e36-electronic.com/photos/M5/rb1.jpg

My bearings looked better than expected for 104k mi:


http://e36-electronic.com/photos/M5/rb4.jpg

I went with custom ACL bearings from Lang Racing ("customized for .0023" to .0025" Bearing Clearance"):



http://e36-electronic.com/photos/M5/rb2.jpg
http://e36-electronic.com/photos/M5/rb3.jpg

Plastigauge looked good:


http://e36-electronic.com/photos/M5/rb6.jpg


http://e36-electronic.com/photos/M5/rb7.jpg

I got the car back together yesterday and everything is fine so far.
Hello mate, what bolts did you use? Also, whats the part number of the ACL you used?

Thanks
 

·
Registered
Joined
·
74 Posts
Discussion Starter #7

·
Registered
Joined
·
163 Posts
Not looking forward to pulling mines out 120-130k but when I do i'll let you know how the WPC coated 702/703's held up.
 

·
Registered
Joined
·
519 Posts
Just started my rb job today. I’m using acl hx, plasi gauge all within 2.5 to 3 thousandths. I plan on using a lighter oil so some extra space is worth it. Can’t wait to have it done.
 

·
Registered
Joined
·
341 Posts
I never took a note of the stamped letters on the bearings itself. I just hate seeing people getting ripped off. Chances are, they're selling off the shelf HX ACL, mixing it with the standard clearance ACL bearing as the lower shell, and marking them up. No need for that. Just get the hx and be done with it for anyone else thinking of doing this.
 

·
Registered
Joined
·
74 Posts
Discussion Starter #12
I never took a note of the stamped letters on the bearings itself. I just hate seeing people getting ripped off. Chances are, they're selling off the shelf HX ACL, mixing it with the standard clearance ACL bearing as the lower shell, and marking them up. No need for that. Just get the hx and be done with it for anyone else thinking of doing this.
Mine were all marked H.
 

·
Registered
Joined
·
5,663 Posts
...No need for that. Just get the hx and be done with it for anyone else thinking of doing this.
That is a fairly speculative statement. I personally wouldn't build a motor up with HX bearings alone unless it was a race motor. Too much clearance, IMO.

I have a set of H and a set of HX and will be taking some measurements and mixing sets this week testing for an S65 race motor.
 

·
Registered
Joined
·
519 Posts
That is a fairly speculative statement. I personally wouldn't build a motor up with HX bearings alone unless it was a race motor. Too much clearance, IMO.

Can the same be said when using a lighter oil? From my understanding a lighter weight oil will have more volume so that clearance will be negligible with a higher volume of oil. That was in the clevite info you gave me awhile ago. Good reading btw.
 

·
Registered
Joined
·
163 Posts
Can the same be said when using a lighter oil? From my understanding a lighter weight oil will have more volume so that clearance will be negligible with a higher volume of oil. That was in the clevite info you gave me awhile ago. Good reading btw.
Will lighter oil equate to more volume? I thought the oil sprayers can only spray so much oil? It wouldn't make sense that when the oil is lighter it magically sprays more oil. Unless I'm not understanding how that works.
 

·
Registered
Joined
·
341 Posts
i'm not going to argue with jcolley however I will say I don't see issue with larger gap in any engine as long as oil pressure holds and there's no journal/bearing contact.

You want to keep 10w-60 with larger gap. IMHO, if you go thinner oil with larger gap, it may have opposite effect than what stock s85 experiences: the oil may get out too quickly causing bearing contact.

As long as there's no contact and no oil pressure issues, I see no disadvantage to the slightly larger gap that ACL HX offers.

I plan on proving my point after 50k miles on my HX bearing set. I will take it apart and let the forum know. It will probably take me about 3 years to rack up that mile. It doesn't see any track time, but I rev it to redline every chance i get.
 

·
Registered
Joined
·
519 Posts
Will lighter oil equate to more volume? I thought the oil sprayers can only spray so much oil? It wouldn't make sense that when the oil is lighter it magically sprays more oil. Unless I'm not understanding how that works.


It’s not magic, it hydraulic’s and I’m not here to teach science. Think of a garden hose, how much can you push through it depending on the fluids viscosity.
 

·
Registered
Joined
·
163 Posts
It’s not magic, it hydraulic’s and I’m not here to teach science. Think of a garden hose, how much can you push through it depending on the fluids viscosity.
Yikes. I hope you didn't take that offensively. I was honestly asking a question.

It makes sense that the total volume being sent through the sprayer would increase over the same period of time. But in my mind how would that affect the bearings with clearances so small. In my mind that's similar to saying let me wash this bean with my sink, but it'll be cleaner if I wash it with a fire hose. I don't understand how surface area can increase with changing oil viscosity.
 

·
Registered
Joined
·
75 Posts
Just started my rb job today. I’m using acl hx, plasi gauge all within 2.5 to 3 thousandths. I plan on using a lighter oil so some extra space is worth it. Can’t wait to have it done.
You got it way wrong. Lighter oil and wider clearance will give you more issues than you are bargaining for...
 
1 - 20 of 66 Posts
Top