993 head stud torque (3.2 engine) + cam timing measurement

strictly · 05-08-2016, 08:52 AM

I have a 1984 3.2 carrera engine rebuilt to 3.5

Its a long story, someone has disassembled the left side only (cam towers, and heads, pistons/cylinders still fited). It has fully threaded head studs, which im 99% sure are the 993 ones. I'll check with a magnet later.

=== Head Stud Torque ===

What torque figure do i use is it 25ft ib (two stage) or 15ft +90 degrees?

Dry, or lubed threads?

=== Cam Timing ===

The right side of the engine is still fully assembled. I am going to measure the cam just for reference purposes. Will i get a correct reading with the hydraulic tensioner still fitted?

Its sat for years. I have the stomski mechanical tensioners.

Once i have worked out the cam timing/grind. I obviously need to set up the left side. Should i redo the right side, or just leave alone? I guess that answer depends on what i measure vs what it should be, which im still trying to work out.

911pcars · 05-08-2016, 09:00 AM

Head torque will be only one of several specs you will need to complete this task. Got a manual or other tech source? If not, get one/some (Internet is your friend). One false number from one of us might not be good for you or engine.

MHO,
Sherwood

strictly · 05-08-2016, 11:28 AM

hi thanks i have a few, waynes rebuild book, bentley, anderson's, etc but just looking for other advice, in case it was different. I have allready read someone posts that used the recommened 25ft Ib (and the heads were leaking) and then moved to 15 plus 90 degrees for the 993 studs and all was well, so just looking for more confirmation as to whether i should follow

strictly · 05-09-2016, 12:55 AM

bump - any other thoughts?

chris_seven · 05-09-2016, 05:18 AM

I think that there may be some slightly incorrect information here.

The Early Workshop Manual recommends that the tightening torque should be 24lbsft and I would tend to lightly oil the nut.

In later years this changed to a two-stage method of torque to 15Nm (11lbsft) followed by 90 degrees.

This should produce a very similar preload in the stud but should reduce the scatter normally associated with simple 'torque tightening'.

strictly · 05-09-2016, 11:55 AM

Quote:

Originally Posted by chris_seven

I think that there may be some slightly incorrect information here.

The Early Workshop Manual recommends that the tightening torque should be 24lbsft and I would tend to lightly oil the nut.

In later years this changed to a two-stage method of torque to 15Nm (11lbsft) followed by 90 degrees.

This should produce a very similar preload in the stud but should reduce the scatter normally associated with simple 'torque tightening'.

Hi chris, thanks for that. The 15nm (11ft) + 90 is what i keep hearing, i just didnt have a book that said it (im going to buy one, lol!). Thanks for the confirmation, im going to go with that. And im going to oil the nuts as well.

Thanks just what i needed to hear =)