Range Rover P38
12
ENGINE
NEW RANGE ROVER
32
REPAIR
Inspection
Valves
17. Remove carbon from valves, valve guides and
seats.
18. Check valves for signs of burning, cracking and
pitting of valve seats.
19. Check head diameter of each valve:
Inlet = 36.0 mm (1.42 in)
Exhaust = 31.0 mm (1.22 in)
20. Check stem diameter of each valve, half-way
along stem and compare diameters with
dimensions given to determine stem sizes of
valves fitted and valve stem wear.
Standard:
Inlet = 6.97 mm (0.274 in)
Service limit = 6.95 mm (0.273 in)
Exhaust = 6.95 mm (0.273 in)
Service limit = 6.93 mm (0.272 in)
1st oversize:
Inlet = 7.07 mm (0.28 in)
Service limit = 7.05 mm (0.277 in)
Exhaust = 7.06 mm (0.278 in)
Service limit = 7.04 mm (0.27 in)
2nd oversize:
Inlet = 7.17 mm (0.282 in)
Service limit = 7.15 mm (0.28 in)
Exhaust = 7.16 mm (0.281 in)
Service limit = 7.14 mm (0.279 in)
21. If valve stems are worn in excess of service
limits, valves with next oversize stems must be
fitted and valve guides reamed to correct size.
Valve guides
CAUTION: Prior to checking/reaming valve
guides, check cylinder head for warping.
See Cylinder head gasket.
22. Position a suitable DTI to cylinder head adjacent
to No.1 valve seat.
23. Insert a new valve with same stem diameter as
the original in the valve guide.
24. Position end of valve stem flush with spring end
of guide.
25. Move valve away from DTI, pre-load gauge and
note pre-load reading.
26. Move valve towards DTI, note gauge reading
and subtract pre-load from this figure. Compare
final figure obtained with tilt figure:
Valve tilt - inlet and exhaust = 0.5 mm (0.02 in).
27. If tilt figure exceeds above dimension, original
valve must be replaced with next oversize valve
and valve guide reamed to next oversize.
Valve guide inside diameter - inlet and exhaust:
Standard = 7.0 mm (0.275 in)
For 1st oversize valve stem = 7.1 mm (0.28 in)
For 2nd oversize valve stem = 7.2 mm (0.283 in)
NOTE: Valve guides may not be replaced.