Stag Head Tension

by Tim Buja from the Stag Repair Operations Manual

According to my Stag Repair Operations Manual, the head torquing procedure (12.29.27) is as follows:

 -------------------
|D   B   A   C   E  | <--nuts on studs
|                   |
|                   | front of head
|                   |
|I   G   F   H   J  | <--bolts
 -------------------
  1. Tighten cylinder head nuts as follows: A, B, C, D, E
  2. Tighten cylinder head bolts as follows: F, G, H, I, J
  3. Tighten two bolts securing front cover to cylinder head. Tighten 1 and 2 to torque 45 to 55 lbf ft (6.2 to 7.6 kgf m)

Note: Fit cylinder head studs to full depth of thread, finger-tight.

The torque wrench settings in the front of the ROM list the following:

Cylinder head attachment bolt: 7/16″ U.N.C. 7.6 kgf m 55 lbf ft
Cylinder head attachment stud: 7/16″ U.N.C. 7.6 kgf m 55 lbf ft
Timing cover to cylinder head: 5/16″ U.N.F. 2.8 kgf m 20 lbf ft

In addition, the ROM procedure for refitting the cylinder head (12.29.10) specifies a torque figure of 55 lbf ft (7.6 kgf m) for the nuts and bolts, and also includes the following:

  1. After 1600 kilometers (1000 miles) running, recheck the cylinder head fixings for correct tightness, as follows.
  2. With the engine cold and working in sequence shown in Operation 12.29.27, slacken each fixing in turn, approximately one flat, then re-tighten to the correct torque figures.

Triumph Stag Repair Operations Manuals are currently available from EWA in New Jersey, USA or directly from the publisher ( Robert Bentley ). I have done an Alta Vista search on “Triumph Stag” and it found a link directly to the Robert Bentley site where you can order the manual as well as the original BL Spare Parts Catalog.

Tim Buja, TKBuja@insightbb.com
80 TR8, 73 Stag, 72 TR6