CYLINDER HEAD—E.7
5.
Locate the spring seat locating washers, valve
springs and spring retainers in their correct
positions on the valve stems.
6.
Using a suitable valve spring compressor (See Fig.
E.4) compress each valve spring in turn and fit the
valve collets.
Note:
As from Engine No. LD U778518H, 'O'
ring seals have been fitted in the
valve spring caps under the collets.
The valve spring caps have been
changed which have a deeper body
so that the seal can be fitted as
shown in Fig. E.9. The new caps are
fitted to both valves, but the seals are
fitted to exhaust valves only.
To Refit the Cylinder Head
Before assembling the cylinder head to the engine it is
extremely important to ensure that the cylinder block and
cylinder head faces are perfectly clean. Care must be
taken to ensure that the rocker assembly oil feed
passage in the cylinder head is free from obstruction.
Whenever the cylinder head is removed, it should not
be refitted with the old gasket, whatever the gasket
condition.
IMPORTANT: Always ensure the correct gasket is
fitted. The thickness of gaskets varies according to the
piston height as given on Pace B.2 and exhaust valve
depths as given on Page B.7 and if the correct gasket is
not used, then piston/valve contact may result.
1.
Current type cylinder head gaskets should be fitted
DRY. On no account should jointing compound be
used.
Before placing gasket over cylinder head studs,
ensure it is correctly positioned. Gaskets are
marked to indicate how they should be fitted.
2.
Place the cylinder head in position on the cylinder
block.
Lightly
oil
threads
and
tighten
nuts/setscrews progressively (in 3 stages) in the
order shown in Fig. E.11 to a torque of 100 lb ft
(13,8 kgf m) — 136 Nm. The final stage should be
repeated to ensure that no loss of tension has
occurred earlier in the tightening sequence.
3.
Fit the push rods in their respective positions and
assemble the rocker shaft assembly to the cylinder
head. Ensure that a new rubber sealing ring is
fitted to the rocker oil feed connection and that it is
correctly positioned before tightening down the
rocker shaft assembly.
Fig E.10.
Showing location of "O" Ring prior to fitting Rocker
Shaft.
When fitting the seal to the rocker oil feed
connection,
the
seal
should
be
positioned
immediately below the 'bottom convolution so that
when the pipe is inserted into the cylinder head.
the "0" ring will roll up and over the lower
convolution and locate itself between the two
convolutions. With current engines, the seal should
be fitted to butt up against the lower convolution
(see Fig. E.10).
Fig. E.11.
Cylinder Head Nut Tightening Sequence.
