: Torque specs on fasteners - torque angle?



eyewonder
03-05-12, 10:41 AM
The FSM gives torque instructions such as: 1st pass, 30 lbs-ft, 2nd pass 60 degrees, 3rd pass 60 degrees. 4th pass 60 degrees.

In the above hypothetical example, are they speaking of actual bolt/nut rotation of 60 degrees? Three separate times, for a total of 180 degrees? As in after tightening using a conventional torque wrench set to 30 lbs-ft, then using a break-over bar, with the break-over bar starting at 12 O'Clock position, and ending at the 6 O'Clock position?

I will be using Jake's studs for the block - do they have a similar sequence using a 'torque angle'? Or just a single tightening to his specified 75 lbs-ft?

When I looked at specs for the connecting rod bolts, they had torque to some number (can't remember exactly) then BACK TO ZERO, then torque to some number. Do they mean to completely break free the con-rod nut?

Cheers,
Steve

Ranger
03-05-12, 11:23 AM
The FSM gives torque instructions such as: 1st pass, 30 lbs-ft, 2nd pass 60 degrees, 3rd pass 60 degrees. 4th pass 60 degrees.

In the above hypothetical example, are they speaking of actual bolt/nut rotation of 60 degrees? Three separate times, for a total of 180 degrees?
Yes.


I will be using Jake's studs for the block - do they have a similar sequence using a 'torque angle'? Or just a single tightening to his specified 75 lbs-ft?

The studs are not torqued as above with torque angle. Just use his spec's. The nut on top gets torqued to factory spec's with torque angels.

Submariner409
03-05-12, 11:24 AM
Initial torque plus XXX degrees in steps is just that - Torque to XX ft/lb (or in/lb), then rotate the bolt/nut XX degrees, then XX degrees, then the final XX degrees for a total of: Initial torque + XXX degrees. You can get very close without using a degree plate by watching the position of the 6 flats on the nut or bolt. You can even make a base reference mark with a magic marker - after the initial torque.

Rod bolts: Torque to spec to crush the bearing shells, release torque, torque to spec - in steps - you don't just torque one side to spec, then the other: you alternate bolts and sneak up on final torque in several increasing steps.

Head bolts/nuts - torque to final specs in several steps, following the recommended sequence - NEVER torque one bolt or nut straight to final setting - always work around the sequence in steps.

maeng9981
03-05-12, 06:59 PM
Studs are put in the block with your finger torque. Countersink the top of the threads for about 1/16"(important or gasket damage/failure can happen). Make sure the threadlocker did its job, and then put the head on the block. Follow the factory torqueing sequence/pattern and Jake's torque specs.

http://i.imgur.com/63CkS.png

For head stud nuts-
1st Pass - 30 ft·lbs
2nd Pass - 60 ft·lbs
3rd Pass - 75 ft·lbs for black/dark colored studs
      80 ft·lbs for shiny/chrome finish studs

For 11/12/13 - 106 in·lbs.

89falcon
03-06-12, 02:11 AM
and 11/12/13 are INCH POUNDS!!!!!!!!!!! (about 9 ft lbs)

I've seen some folks try to torque the tiny bolts up to 106 ft lbs......needless to say, they didn't get there....