Land Rover V8 engine. Manual — part 8
ENGINE
18
OVERHAUL
Oil pressure relief valve - remove
1. Remove circlip.
2. Remove relief valve plug, remove and discard
’O’ ring.
3. Remove relief valve spring and piston.
Oil pump - inspection
1. Thoroughly clean oil pump drive gear, cover
plate, rotors and housing. Remove all traces of
Loctite from cover plate securing screws;
ensure tapped holes in timing cover are clean
and free from oil.
2. Check mating surfaces of cover plate, rotors
and housing for scoring.
3. Assemble rotors and oil pump drive gear in
housing ensuring that reference marks are
aligned.
4. Using feeler gauges, check clearance between
teeth of inner and outer rotors:
Maximum clearance = 0.25 mm
5. Remove oil pump drive gear, check depth of
any wear steps on gear teeth:
Wear step maximum depth = 0.15 mm
ENGINE
OVERHAUL
19
6. Place a straight edge across housing.
7. Using feeler gauges, check clearance between
straight edge and rotors:
Maximum clearance = 0.1 mm
Oil pressure relief valve - inspection
1. Clean relief valve components and piston bore
in timing cover.
2. Check piston and bore for scoring and that
piston slides freely in bore with no perceptible
side movement.
3. Check relief valve spring for damage and
distortion; check spring free length:
Spring free length = 60.0 mm
Oil pump - refit
1. Lubricate rotors, oil pump drive gear, cover
plate and housing with engine oil.
2. Assemble rotors in housing ensuring that
reference marks are aligned.
3. Position cover plate to housing.
4. Apply Loctite 222 to threads of cover plate
screws, fit but do not fully tighten screws.
5. Position drive gear in oil pump, tighten cover
plate screws to correct torque.
6. Fit timing cover.
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.
ENGINE
20
OVERHAUL
CAMSHAFT AND TAPPETS
Camshaft and tappets - remove
1. Remove rocker shaft assemblies.
2. Remove pushrods and store in fitted order.
3. Remove timing chain and gears.
4. Remove tappets and retain with their
respective pushrods.
NOTE: If tappets cannot be removed due
to damaged camshaft contact area,
proceed as follows:
5. 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 is
removed.
6. Withdraw camshaft, taking care not to damage
bearings in cylinder block.
Camshaft and tappets - inspection
1. Throughly 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.
4. 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.
5. 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 engine block.
6. Ensure that tappets rotate freely in their
respective bores.
7. Inspect pushrod contact area of tappet, replace
tappet if surface is rough or pitted.
ENGINE
OVERHAUL
21
Camshaft and tappets - refit
1. Lubricate camshaft journals with clean engine
oil and carefully insert camshaft into cylinder
block.
2. Immerse tappets in clean engine oil. Before
fitting, pump the inner sleeve of tappet several
times using a pushrod, to prime tappet and
reduce tappet noise when engine is first
started.
3. Lubricate tappet bores with clean engine oil
and fit tappets in removed order.
NOTE: Some tappet noise may be evident
on initial start-up. If necessary, run the
engine at 2500 rev/min for a few minutes
until noise ceases.
4. Fit timing chain and gears.
5. Fit rocker shaft assemblies.
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. Remove plastic tubing from connecting rod
bolts.
7. Repeat above procedure for remaining pistons.
Piston rings - remove
1. Using a suitable piston ring expander, remove
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.
Piston rings - inspection
1. Temporarily fit new compression rings to
piston.
NOTE: The ring marked ’TOP’ must be
fitted, with marking uppermost, into
second groove. The chrome ring fits into
top groove and can be fitted either way round.
2. Check compression ring to groove clearance:
Top compression ring A = 0.05 to 0.10 mm.
2nd compression ring B = 0.05 to 0.10 mm.
3. Insert new piston ring into relevant cylinder,
held square to bore with piston, and check ring
gaps.
Top compression ring = 0.44 to 0.57 mm.
2nd compression ring = 0.44 to 0.57 mm.
Oil control ring rails = 0.38 to 1.40 mm.
4. Use a fine-cut flat file to increase gap if
required. Select a new piston ring if gap
exceeds limit.
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