Main bore dimensions

[Mspir3d]

I’ve got a set of arp main studs going into my engine but the machine shop is concerned with the studs altering the main bore. Does anyone have the dimensions and tolerances for the main bore?

thanks

[robgill]

Valid concern, ARP studs/bolts have a different clamping force than the OE bolts. The best way to do it is torque the ARP bolts down to their spec and then line bore the mains. Or just stick with the OE bolts.

Page 43 in this doc has the specs:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/414-e46-m3-torque-spec-thread-every-bolt-on-the-car-on-diagrams#post5291

[Mspir3d]

Thanks! I would not have thought to check that document. It looks like the measurement may be with the bearing installed though.

[Mspir3d]

Bump, does anyone know the measurement without the bearing? Looks to be around 65 mm

[digger]

https://aclperformance.com.au/details/7M1532HX/BMW%20S54B32%203246cc%20Inline6%20DOHC%204v/

[Mspir3d]

Just what I needed, thanks!