ground clearance JAGUAR XJ 1994 2.G AJ16 Engine Manual

AJ16 Engine Service Manual
. The dimension must be taken between the valve stem and
the back of the cam. Should
this dimension not be ob-
tained, metal must be ground from thevalveseat of the in-
sert.
&&: Use only suitable grinding equipment.
* Remove only very small amounts of metal from the valve
seat at one time before re-checking the clearance.
. Examinethecamfollowersforwear on the topface. Check
for any sign of barreling on the side faces (Fig. 1). Renew
all followers that are worn or suspect. Wash the valves,
springs, collets, followers and air dry.
. After the valve springs have been thoroughly washed,
they must be examined for fatigue and distortion. Renew
as necessary.
. Test the valve springs either by comparison with the fig- ures given in Service Data in the Preliminary Pages, or by
comparison with a new valve spring (using a recom- mended valve spring testing machine).
. To test against a new valve spring, insert both valve
springs end to end between the test equipment. Apply a
load to partly compress the springs and measure their
comparative lengths (Fig.
2).
&@:
. If the distance 'A' is smaller than the distance 'B', then 'A'
b: Spring distortion is determined by positioning the
spring upright on a surface plate and checking the
squareness of each end with a set square (Fig.
3). All
valve springs which have diminished in length and/ or are not square must be renewed.
. Fit the valves into the guides and place the cylinder head
on wooden blocks.
. Fit the valve spring seats, intake valve guide oil seals,
springs and collars.
. Compress the springs using Service Tool MS 1519A and
insert the split collets.
. Refit the original shims (1 Fig. 4) in the valve collar re- cesses. (Ensure that the shims are seated correctly and fit
the cam followers, see Section 4.3).
If the cylinder head has been overhauled to the ex-
tent of having the valve seats recut, each shim
should be 0,010 in. smaller than the original.
. Lubricatethecamshaftsand fittothecylinder head,ensur- ingthattheyarefittedwiththeslotsto thetop. Fitthecam- shaft caps and torque tighten the securing bolts. Measure
the valve clearance between the heel of the cam and the
cam follower, turning the camshaft as necessary to
measure
all the clearances see Section 4.3.
It is advisable to set the valve clearances to the
upper
limit to allow for the clamping effect exper- ienced through torque tightening upon engine re- assembly.
Afinal checkof the valve clearances should be done
when the cylinder head is fitted and torque tigh
- tened to the cylinder block.
Clean the cylinder head thoroughly and checkthe cylinder
head and cylinder block for warping, bowing or cracks.
. Fit the cylinder head, see Section 4.4.
'A' is the old spring.
must be renewed.
&&:
m:
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Fig. 1
K
Fig. 2
I Fig. 4
Issue 1 August 1994 18