Torque Values for XPAG and XPEG Engines


Engine


Gudgeon pin clamp bolt
Rod big end bolts
Main bearing cap nuts
Flywheel to crankshaft bolts
Clutch pressure plate bolts
Oil pickup pipe to sump bolts
Camshaft locating plate bolts
Camshaft sprocket bolt
Timing chain tensioner bolts
Sump to block bolts
Timing chain cover bolts
Crankshaft pulley bolt
Cylinder head nuts
Rocker tower bolts (8 mm)
Rocker tower bolts (10 mm)
Oil pump to block bolts
25 lbft
25
63
50
19
6
6
50
6
19
19
50
50
16
43
6


Other

Water pump pulley nut
Generator pulley nut
Transmission output flange nut
Rear axle hub nut
Front axle hub nut
Wheel lug nuts
10 lbft
35
65
170-200
40-70
50


The following thoughts are offered by Carl Cederstrand, a well known M.G. enthusiast and life-long engineer.

I would like to add a comment on tightening head bolts. Measuring the torque is Donald Duck way of setting the clamping force. The torque varies with the smoothness of the threads and with any grease or oil on the threads. A better way is to set a dial indicator in contact with the top of the stud and then tighten the head nut until the stud is elongated by an amount that indicates the desired clamping force. This is the way it is done in Germany and it is a superior technique.

When tightening head studs on our T-Series use a torque wrench that has a dial indicator so that it gives a continuous torque reading. As one tightens the nut, the torque reading increases. Then suddenly the torque no longer increases as the nut is turned. Stop! You have reached the elastic limit of the stud. Further turning of the nut will only snap off the stud!

I always limit the torque I apply on the head nuts to 90% of the recommended factory value. The factory suggested value does NOT allow for the smoothing of the threads that occurs with use. The 90% value has worked fine for me for decades.

Best wishes,
Carl Cederstrand