Exhaust studs 3.6L conflicting info

[lightbulb8817]

I'm reading conflicting info on how to install and tighten exhaust studs (head to heat exchanger studs) for a 3.6L motor (993).

Do I hand tighten or torque down? If i torque down, how tight? Do I use any antiseize or loctite?

I've been reading tighten anywhere from 0 to 21 ft lbs and from no lubricate to copper anti seize to red loctite...

It seems that the original studs were 8 x 22 but were superseded by 8 x 38, which is also confusing in itself. How did they get the 22 length to work originally? i purchased the 38 ones.

I'm trying to avoid issues with broken studs down the road. Any advice is appreciated!

[jrbennett]

Porsche parts diagrams/PET usually list the exposed length of the stud rather than the overall length.
It is very possible the 8x38 studs will only have 22mm exposed once installed.

I personally have installed studs with and without the Loctite, I think the main purpose is to keep them from pulling out when removing the nuts.

I usually put a small dab of copper paste on the exposed threads of the studs or on the inside of the nuts.

As for installation, I put everything on hand tight, torque the cross-over pipes/cats first then torque the heat exchangers to the heads (18-22 ft/lbs)