Aftermarket Main Bearings: Glyco, King, or ACL?

[SteelGreyM]

As many of you know I’m currently doing a rebuild. I’m currently choosing between 3 brands of main bearings. I don’t think there’s any bad choice honestly because people have success with all options however I’m interested in hearing some opinions.

I think glyco is OE but I’m not sure.

[Obioban]

Whatever bearings you decide on, use OE bolts

[Johnvu]

Whatever bearings you decide on, use OE bolts

Are new bolts a must?

[Obioban]

Are new bolts a must?

Depends on the year of your car. BMW changed bolts in 2002(?)— earlier cars reuse the bolts, later cars need them replaced.

[heinzboehmer]

Depends on the year of your car. BMW changed bolts in 2002(?)— earlier cars reuse the bolts, later cars need them replaced.

That's for rod bearings though. Main bearing bolts weren't changed.

[SteelGreyM]

That's for rod bearings though. Main bearing bolts weren't changed.

TIS doesnt say "use new bolts"

but it does say "use old main bearing cap bolts when checking clearances"

So im gonna guess they recommend it but isn't required. either way its not much extra and is not worth the risk.

Whatever bearings you decide on, use OE bolts

Whats wrong with ARP studs?

[Obioban]

I misread the thread title; assumed rod bearings.

[Obioban]

Whats wrong with ARP studs?

The reason I said use OE bolts when I thought you were talking about rod bearings is that stock has more clamping force, creates a rounder bore, and is cheaper than ARP. I haven't seen anyone analyze that mains, so don't know if that's also the case there... but we do know that stock is in no way insufficient, so unless the ARPs are cheaper (assuming they're one time use) there's no way I'd change... and probably not even if they were cheaper.

[George Hill]

TIS doesnt say "use new bolts"

but it does say "use old main bearing cap bolts when checking clearances"

So im gonna guess they recommend it but isn't required. either way its not much extra and is not worth the risk.

TIS DOES say to use NEW bolts. Under the tightening torque it says "Replace, wash and oil screws." It says use old bolts when checking clearance because they are 1x use. *Torque is 25Nm + 50*

[Syfon]

FWIW I'm awaiting parts to re-build my S54. March 2004 build.

I've decided on ACL Race Series bearings for both the rods and mains. #1 Lang Racing use ACL bearings; if they're good enough for them, they're most certainly good enough for me. #2 They're made in Tasmania, Australia; I'm supporting an Aussie business. #3 They were a shitload cheaper than OE bearings.

As for the main bolts, mine will be replaced with brand new OE items. No reason other than "while I'm in there" lol.

[F1Dryvr]

I went with king, on lange's recommendation. Ive read the mains are not a wear item but somehow one of the bearings had significant scoring with several edges my fingernail cought. Crank didnt seem too bad.

[SteelGreyM]

I went with king, on lange's recommendation. Ive read the mains are not a wear item but somehow one of the bearings had significant scoring with several edges my fingernail cought. Crank didnt seem too bad.

Lang also recommended king bearings to me. Did you measure clearances?

FWIW I'm awaiting parts to re-build my S54. March 2004 build.

I've decided on ACL Race Series bearings for both the rods and mains. #1 Lang Racing use ACL bearings; if they're good enough for them, they're most certainly good enough for me. #2 They're made in Tasmania, Australia; I'm supporting an Aussie business. #3 They were a shitload cheaper than OE bearings.

As for the main bolts, mine will be replaced with brand new OE items. No reason other than "while I'm in there" lol.

I have heard that while king used to be better their production quality has dropped and ACL is the new better one.

Does anyone know anything about glyco? Im pretty sure theyre the OE. Can someone confirm?

[F1Dryvr]

No but im getting the widened rod bearing journal crank, ill ill to check clearances after i get it. He thinks ill be slightly over .002

[SteelGreyM]

No but im getting the widened rod bearing journal crank, ill ill to check clearances after i get it. He thinks ill be slightly over .002

Was the damaged bearing by chance the middle bearing?

[Mspir3d]

I had some wear on one main bearing as well near the center iirc. All of the others looked perfect after 190k miles. replaced the mains with glyco from fcpeuro. The clearance was fine.