Land Rover V8 engine 4.0, 4.6 litre. Manual — part 12
ENGINE
30
OVERHAUL
Cylinder liner bore - inspection
1. Measure cylinder liner bore wear and ovality in
two axis 40 to 50 mm (1.5 to 1.9 in) from top of
bore.
Cylinder liner bore:
Grade ’A’ piston fitted = 94.00 to 94.015 mm
(3.700 to 3.701 in)
Grade ’B’ piston fitted = 94.016 to 94.030 mm
(3.7014 to 3.702 in)
Maximum ovality = 0.013 mm (0.0005 in)
Cylinder liners having grade ’A’ pistons fitted
may be honed to accept grade ’B’ pistons
provided specified wear and ovality limits are
maintained.
CAUTION: The temperature of piston and
cylinder block must be the same to ensure
accurate measurement.
2. If only new piston rings are to be fitted, break
cylinder bore glazing using a fine grit, to
produce a 60
°
cross-hatch finish. Ensure all
traces of grit are removed after above
operation.
3. Check alignment of connecting rods.
ENGINE
OVERHAUL
31
Pistons - refit
CAUTION: Pistons have a 0.5 mm (0.02 in)
offset gudgeon pin which can be identified
by an arrow mark on the piston crown.
This arrow MUST always point to the front of the
engine.
1. Assemble pistons to connecting rods with
arrow on piston pointing towards domed
shaped boss on connecting rod for RH bank of
cylinders, and arrow pointing away from dome
shaped boss for LH bank of cylinders.
2. Clamp hexagon body of LRT-12-013 in vice.
3. Slacken large nut and pull the centre screw
50.8 mm (2.0 in) out of hexagon body.
4. Locate remover/replacer adapter
LRT-12-126/2 with its long spigot inside bore
of hexagon body.
5. Fit remover/replacer adapter LRT-12-126/3
with cut-out towards piston, up to shoulder on
centre screw.
6. Lubricate gudgeon pin and bores of connecting
rod and piston with graphited oil.
7. Locate connecting rod and piston to centre
screw with connecting rod entered on sleeve
up to groove.
8. Fit gudgeon pin on to centre screw and into
piston bore up to connecting rod.
9. Fit remover/replacer bush LRT-12-126/1 with
flanged end towards gudgeon pin.
10. Screw the stop nut onto centre screw and
position piston against cut-out of adapter
LRT-12-126/3.
11. Lubricate centre screw threads and thrust race
with graphited oil, screw large nut up to
LRT-12-013.
12. Lock the stop nut securely with lockscrew.
13. Set torque wrench to 16 Nm (12 lbf.ft), and
using socket on large nut, pull gudgeon pin in
until flange of LRT-12-126/1 is distance A
from face of piston.
Distance A = 0.4 mm (0.016 in).
CAUTION: If torque wrench ’breaks’
during above operation, fit of gudgeon pin
to connecting rod is not acceptable and
components must be replaced. The centre screw
and thrust race must be kept well lubricated
throughout operation.
14. Dismantle tool, remove piston, check no
damage has occurred during pressing and
piston moves freely on gudgeon pin.
15. Repeat above operations for remaining
pistons.
ENGINE
32
OVERHAUL
Piston to cylinder bore clearance - checking
1. Starting with number 1 piston, invert piston and
with arrow on piston crown pointing towards
REAR of cylinder block, insert piston in cylinder
liner.
2. Position piston with bottom of skirt 30 mm (1.2
in) from top of cylinder block.
3. Using feeler gauges, measure and record
clearance between piston and left hand side of
cylinder - viewed from front of cylinder block:
Piston to bore clearance = 0.02 to 0.045 mm
(0.001 to 0.002 in)
4. Repeat above procedures for remaining
pistons.
Pistons and connecting rods - refit
1. Fit oil control ring rails and expander, ensuring
ends butt and do not overlap.
2. Fit 2nd compression ring marked ’TOP’ with
marking uppermost into second groove.
3. Fit 1st compression ring into first groove either
way round.
4. Position oil control expander ring joint and ring
rail gaps all at one side, between gudgeon pin
and away from left hand (thrust) side of piston -
viewed from front of piston. Space gaps in ring
rails approximately 25 mm (1.0 in) each side of
expander ring joint.
5. Position compression rings with ring gaps on
opposite sides of piston between gudgeon pin
and right hand side of piston - viewed from
front of piston.
6. Thoroughly clean cylinder bores.
7. Lubricate piston rings and gudgeon pin with
engine oil.
8. Lubricate cylinder bores with engine oil.
ENGINE
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33
9. Fit ring clamp to piston and compress piston
rings.
NOTE: Connecting rods shown in final
fitted positions.
10. Insert connecting rod and piston assembly into
respective cylinder bore ensuring domed
shaped boss on connecting rod faces towards
front of engine on RH bank of cylinders, and
towards rear on LH bank of cylinders.
11. Fit big-end bearing caps and bearing shells.
12. Fit cylinder head(s).
FLYWHEEL AND STARTER RING GEAR
Flywheel - remove
1. Restrain crankshaft and remove 6 bolts
securing flywheel.
2. Remove flywheel.
NOTE: Dowel located
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