'70 Head Bolt Torque

[TVollnogle]

I'm reassembling my '70 Z engine after overhaul and am finding conflicting values for the head bolt torquing. It has an E31 head, with engine block

#005953. I purchased new head bolts from Nissan.

Tom Monroe's "How to Rebuild your Nissan..." gives 61 ft-lbs.

The Henley Shop Manual gives 47 ft-lbs.

The Clymer Manual says on L24's up to block number 27000 or so (I'm going from memory since I'm out of town and don't have the manual with me) that the torque is 51 ft-lbs.

Has anyone run up against this before? Any ideas?

Thanks.

Terry

'70 240Z #3212

[civ104]

I amquoting from the 1970 240Z FSM and it says. Cylinder Head bolts 1st turn: 4.5kg-m (32.5 ft-lb) 2nd turn 6.5 kg-m (47.0 ft-lb) I will post the page if requested.

[kinfish]

Agree with "CIV104" on torque. Manual for my '71 240Z says same 2-step torque values. Most threads on this subject recommend upgrading to the turbo head bolts instead of original bolts. These bolts are made of improved material and hence are torqued slightly higher.

Suggest you verify what bolts you bought from Nissan. I torqued my head in 2-step process with final torque of 55 ft-lbs using turbo head bolts.