ARP head studs vs bolts!

[ramzisleiman]

whats the differece between studs and bolts?.. i read some tech info over arp catalogue and website.. but wasn''t so useful.. i am wondering whats the difference?.. i want to install them on the m30 engine.. does this engine already got studs?? coz as i saw in the pictures studs differ from bolts?!..i mean i saw that bolts are wat every bmw engine got which engage the head to the block..so where are studs?? do we need to make any changes in the block or head to install it ? thanks

[shaeff]

You get a better torque reading, and clamping pressure with the studs. With the bolts, you have to overcome the friction of the block in order to torque them. That's two places of extra friction, the head of the bolt, and the threads.

With the studs, the only friction you need to overcome when torquing is that of the nut on the washer, and of course you should be using ARP's moly lube when assembling, and following their instructions based on your application. (also note that different lubes will require different torque settings. )

[wajouba]

thanks bro !

[nukeduster]

Also keep in mind with studs if on certain applications its very difficult/impossible to remove the head with the engine still installed. Thats why I prefer non-stretch bolts myself. Works perfect on every turbo/sc application Ive ever built before(2 bmws and countless others).

[shaeff]

True, the ARP bolts will be fine for most applications. I'm just anal. LOL. I have ARP studs in my Supra.