Land Rover 4 0 4 6 V8 Engine Overhaul 3rd Edition Rover Manual

							ENGINE
24
OVERHAUL Oil pressure relief valve - refit
1.Lubricate new O ring with engine oil and fit to
relief valve plug.
2.Lubricate relief valve spring, piston and piston
bore with engine oil.
3.Assemble piston to relief valve spring, insert
piston and spring into piston bore.
4.Fit relief valve plug, depress plug and fit circlip.
5.Ensure circlip is fully seated in groove.CAMSHAFT AND TAPPETS
Camshaft end-float - check
1.Remove rocker shaft assemblies.
2.Remove pushrods and store in their fitted
order.
3.Remove timing chain and gears.
4.Temporarily fit camshaft gear bolt.
5.Attach a suitable DTI to front of cylinder block
with stylus of gauge contacting end of
camshaft.
6.Push camshaft rearwards and zero gauge.
7.Using camshaft gear bolt, pull camshaft
forwards and note end-float reading on gauge.
End-float = 0.05 to 0.35 mm (0.002 to 0.014 in)
8.If end-float is incorrect, fit a new thrust plate
and re-check. If end-float is still incorrect, a
new camshaft must be fitted. 
						

							ENGINE
OVERHAUL25
Camshaft and tappets - remove
1.Remove tappets and retain with their
respective pushrods.
2.When tappets prove difficult to remove due to
damaged camshaft contact area, proceed as
follows. Lift tappets in pairs to the point where
damaged face is about to enter tappet bore
and fit rubber bands to retain tappets. Repeat
until all tappets are retained clear of camshaft
lobes. The tappets can then be withdrawn out
the bottom of their bores when the sump and
camshaft are removed.
3.Remove 2 bolts securing camshaft thrust plate
to cylinder block, remove plate.
4.Withdraw camshaft, taking care not to damage
bearings in cylinder block.
NOTE: Camshafts fitted to 4.0 litre engines
are colour coded ORANGE whilst those
fitted to 4.6 litre engines are colour coded
RED. 
						

							ENGINE
26
OVERHAUL Camshaft and tappets - inspection
1.Thoroughly clean all components.
2.Inspect camshaft bearing journals and lobes
for signs of wear, pitting, scoring and
overheating.
3.Support camshaft front and rear bearings on
vee blocks, and using a DTI, measure
camshaft run-out on centre bearing:
Maximum permitted run-out = 0.05 mm (0.002
in)
4.Inspect thrust plate for wear, replace plate if
wear is evident.
5.Clean and inspect tappets. Check for an even,
circular wear pattern on the camshaft contact
area. If contact area is pitted or a square wear
pattern has developed, tappet must be
renewed.
6.Inspect tappet body for excessive wear or
scoring. Replace tappet if scoring or deep wear
patterns extend up to oil feed area. Clean and
inspect tappet bores in cylinder block.
7.Ensure that tappets rotate freely in their
respective bores.
8.Inspect pushrod contact area of tappet, replace
tappet if surface is rough or pitted.Camshaft and tappets - refit
NOTE: If a replacement camshaft is to be
fitted, ensure colour coding is correct.
Camshafts fitted to 4.0 litre engines are
colour coded ORANGE whilst those fitted to 4.6
litre engines are colour coded RED.
1.Lubricate camshaft journals with engine oil and
carefully insert camshaft into cylinder block.
2.Fit camshaft thrust plate, fit bolts and tighten to
25 Nm (18 lbf.ft).
NOTE: If camshaft or thrust plate has been
replaced, it will be necessary to re-check
camshaft end-float.
3.Immerse tappets in engine oil. Before fitting,
pump the inner sleeve of tappet several times
using a pushrod to prime tappet; this will
reduce tappet noise when engine is first
started.
4.Lubricate tappet bores with engine oil and fit
tappets in removed order.
NOTE: Some tappet noise may still be
evident on initial start-up. If necessary, run
the engine at 2500 rev/min for a few
minutes until noise ceases.
5.Fit timing chain and gears.
6.Fit rocker shaft assemblies. 
						

							ENGINE
OVERHAUL27
PISTONS, CONNECTING RODS, PISTON RINGS
AND CYLINDER BORES
Pistons and connecting rods - remove
1.Remove cylinder head(s).
2.Remove big-end bearings.
3.Remove carbon ridge from top of each cylinder
bore.
4.Suitably identify each piston to its respective
cylinder bore.
5.Push connecting rod and piston assembly to
top of cylinder bore and withdraw assembly.
6.Repeat above procedure for remaining pistons.
CAUTION: Big-end bearing shells must be
replaced whenever they are removed.Piston rings - remove
1.Using a suitable piston ring expander, remove
and discard piston rings.
2.Remove carbon from piston ring grooves.
NOTE: Use an old broken piston ring with
a squared-off end.
CAUTION: Do not use a wire brush. 
						

							ENGINE
28
OVERHAUL Piston rings - inspection
1.Temporarily fit new compression rings to
piston.
NOTE: If replacement pistons are to be
fitted, ensure rings are correct for piston.
The 2nd compression ring marked TOP must be
fitted, with marking uppermost, into second
groove. The 1st compression ring fits into top
groove and can be fitted either way round.
2.Check compression ring to groove clearance:
1st compression ringA= 0.05 to 0.10 mm
(0.002 to 0.004 in).
2nd compression ringB= 0.05 to 0.10 mm
(0.002 to 0.004 in).
3.Insert piston ring into its relevant cylinder bore,
held square to bore with piston and check ring
gaps.
1st compression ring = 0.3 to 0.5 mm (0.01 to
0.02 in)
2nd compression ring = 0.40 to 0.65 mm
(0.016 to 0.03 in)
Oil control ring rails = 0.38 to 1.40 mm (0.014
to 0.05 in)
4.Retain rings with their respective pistons.Pistons- remove
1.Clamp hexagon body ofLRT-12-013in vice.
2.Screw large nut back until flush with end of
centre screw.
3.Push centre screw forward until nut contacts
thrust race.
4.Locate remover/replacer adapter
LRT-12-126/2with its long spigot inside bore
of hexagon body.
5.Position remover/replacer adapter
LRT-12-126/3onLRT-12-126/2with cut-out
facing away from body ofLRT-12-013.
6.Locate piston and connecting rod assembly on
centre screw and up to adapterLRT-12-126/2.
7.Position cut-out of adapterLRT-12-126/3to
piston.
CAUTION: Ensure cut-out does not
contact gudgeon pin.
8.Fit remover/replacer bushLRT-12-126/1on
centre screw with flanged end away from
gudgeon pin. Screw stop nut on to centre
screw.
9.Lock the stop nut securely with lockscrew.
10.Push connecting rod to right to locate end of
gudgeon pin in adapterLRT-12-126/2.
11.Screw large nut up toLRT-12-013.
12.Hold lockscrew and turn large nut until
gudgeon pin is withdrawn from piston.
13.Dismantle tool and remove piston, connecting
rod and gudgeon pin.
NOTE: Keep each piston and gudgeon pin
with their respective connecting rod.
14.Repeat above operation for remaining pistons. 
						

							ENGINE
OVERHAUL29
Pistons - inspection
1.Clean carbon from pistons.
2.Inspect pistons for distortion, cracks and
burning.
3.Measure and record piston diameter at 90°to
gudgeon pin axis and 10 mm (0.4 in) from
bottom of skirt.
4.Check gudgeon pin bore in piston for signs of
wear and overheating.
NOTE: Pistons fitted on production are
graded A or B, the grade letter is
stamped on the piston crown.
Production piston diameter:
GradeA= 93.970 to 93.985 mm (3.700 to 3.7002 in)
GradeB= 93.986 to 94.00 mm (3.7003 to 3.701 in)
GradeBpistons are supplied as service
replacements. Worn cylinder liners fitted with grade
Apistons may be honed to accept gradeB
pistons provided that specified cylinder bore and
ovality limits are maintained.
CAUTION: Ensure replacement pistons are
correct for the compression ratio of the
engine. The compression ratio will be
found on the cylinder block above the engine
serial number. Ensure that replacement
connecting rods are correct length for engine
being overhauled.
Connecting rod length between centres:
4.0 litre = 155.12 to 155.22 mm (6.10 to 6.11 in)
4.6 litre = 149.68 to 149.78 mm (5.89 to 5.91 in)Gudgeon pins - inspection
NOTE: Gudgeon pins are only supplied as
an assembly with replacement pistons.
1.Check gudgeon pins for signs of wear and
overheating.
2.Check clearance of gudgeon pin in piston.
Gudgeon pin to piston clearance = 0.006 to
0.015 mm (0.0002 to 0.0006 in).
3.Check overall dimensions of gudgeon pin.
Overall length = 60.00 to 60.50 mm (2.35 to 2.4
in).
Diameter - measured at each end and centre
of pin = 23.995 to 24.00 mm (0.94 to 0.95 in). 
						

							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
OVERHAUL31
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 ofLRT-12-013in 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-12-126/2with its long spigot inside bore
of hexagon body.
5.Fit remover/replacer adapterLRT-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 bushLRT-12-126/1with
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 ofLRT-12-126/1is distanceA
from face of piston.
DistanceA= 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
OVERHAUL33
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