Norton Commando Workshop Manual

## Engine/Primary Transmission

# C

### SECTION C8

### REFITTING ROCKERS

The rocker spindles must be positioned correctly to allow satisfactory lubrication. It is recommended that the cylinder head be heated to 1 50°-200°C. prior to offering the rocker spindles, to facilitate entry and alignment.
Assembly is as follows:
1 | Heat the cylinder head gently.
2 | Engage a rocker spindle into the cylinder head with li flat facing rearwards on the inlet side and forwards on the exhaust and tap it through very gently with a soft drift until it protudes approximately 1/16 in. (1.59 mm) through the outer boss into the rocker cavity.
3 | Fit the plain washer then the rocker in position.
4 | Drive the rocker spindle part way through the rocker and fit the double spring washer between the other end of the rocker and the boss in the rocker box.
5 | Centralise the spring washer and drive the spindle through until it protrudes no more than 3/8 in. (9.52 mm)
6 | Align the rocker spindle as shown in Fig. C7.
| Note: Flat on spindle faces away from centre of head, towards rocker cover.
7 | Drive the spindle home taking care that the rocker spindle does not turn during this operation. The spindle should be flush or fractionally below the joint facing on the rocker box.

### SECTION C9

### REFITTING CYLINDER HEAD

The cylinder head shouid be cleaned, inspected and overhauled as described in previous sections, and the valves and rockers assembled. As with dismantling, the cylinder head and pushrods shouid be offered as a set.
The operation is described fully below:
1 | Place the cylinder head gasket in position on top of the cylinder.
2 | Turn the engine until the pistons are at top dead centre so that there is minimum valve lift and on assembly one pair of pushrods is fractionally higher than the other.

3 | Place the pushrods in the pushrod tunnels in the cylinder head with the inlet pushrods (that is the longer pair) inboard and the shorter exhaust ones, outboard.
| The cupped end of each pushrod is uppermost.
4 | Take the cylinder head firmly in one hand and feed the pushrods as far into the cylinder bead as possible, holding them with the other hand. See Fig. C3.
5 | Place the cylinder head over the cylinder, forward end downwards and allow the pushrods to drop down the cylinder barrel pushrod tunnels. Note that the pushrods cannot do other than locate on the cam followers at the lower end.
6 | Starting with the pair of pushrods which are slightly higher, engage the tops of the pushrods to the rocker ball ends as the cylinder head is lowered. Use an implement such as a thin screwdriver through the exhaust rocker box to guide the pushrods into position as shown in Fig. C8. Having engaged the first pair of pushrods engage the second pair in a similar manner.
The cylinder head is ready to be secured. The tightening sequence is shown in Fig. C2.

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