Land Rover engine 300 TDi. Manual — part 10
ENGINE
20
OVERHAUL
6. Remove spring cup, valve spring and spring
seat. Keep components in their fitted order.
7. Remove and discard valve stem oil seal.
8. Remove valve, and retain in fitted order.
9. Repeat above procedures for remaining
valves.
Cylinder head - inspection
1. Decarbonise cylinder head.
2. Examine cylinder head for cracks, pay
particular attention to area between inlet and
exhaust valve seats. Cracks indicate engine
has overheated and cylinder head must be
replaced.
3. Check core plugs for signs of corrosion and
leakage, replace as necessary.
4. Check cylinder head for warping using a
straight edge and feeler gauges.
Maximum warping = 0.08 mm
CAUTION: Cylinder head must not be
refaced, if warping exceeds figure given,
head must be replaced.
5. Check valve seat inserts for burning, pitting or
damage, replace inserts if pitting cannot be
removed by valve lapping-in or refacing.
ENGINE
OVERHAUL
21
Valve springs - inspection
1. Check free length of each spring = 46.28 mm
2. Check that end coils of each spring are square
to body of spring.
Valves and guides - inspection
1. Remove carbon from valves.
2. Examine head of each valve for cracks and
burning and valve seat for pitting or burning,
replace valves as necessary.
3. Check valve seating faces for pitting, if light
pitting cannot be removed during valve
grinding operations, valves may be refaced.
CAUTION: If refacing results in valve head
stand down being exceeded, valves must
be replaced.
4. Check valve seating face angles.
Inlet = 60
°
00’ to 60
°
30’ - included angle =120
°
Exhaust = 45
°
00’ to 45
°
30’ - included angle =
90
°
5. Reface or replace valves as necessary.
6. Check each valve stem for wear, measure at
each end and centre of valve stem.
Inlet = 7.96 mm
Exhaust = 7.94 mm
7. Replace any valve with stems that are worn.
ENGINE
22
OVERHAUL
8. Insert a new valve into each guide in turn and
with head of valve positioned 8.0 mm above
seat insert, measure side to side movement of
valve head using a suitable DTI.
Maximum valve head movement = 0.15 mm
9. Replace any valve guide which permits valve
head movement in excess of the above figure.
Valve guides - renew
1. Support cylinder head, combustion face
upwards on blocks of wood.
2. Using tool LRT-12-036, drift valve guide out of
cylinder head, discard guide.
3. Clean valve guide bore.
4. Heat cylinder head uniformily to 120
°
C.
WARNING: Take care when handling
heated cylinder head.
ENGINE
OVERHAUL
23
5. Position cylinder head on bed of hand press.
6. Position replacement valve guide to cylinder
head, ensuring that groove for valve stem seal
is facing away from cylinder head.
7. Position distance piece, tool LRT-12-515 and
valve guide replacer LRT-12-046 to valve
guide.
8. Press valve guide into cylinder head until
distance piece contacts face of head; remove
tools.
9. Allow cylinder head to air cool.
Valve seat inserts - refacing
CAUTION: Prior to refacing valve seats,
check valve head stand down. If, after
refacing, valve head stand down will be
below limits, seat inserts must be replaced.
1. Support cylinder head on its side on suitable
blocks of wood.
2. Loosely assemble pilot, tool LRT-12-502 and
a suitable expandable collet, ensuring that
chamfered end of expander is towards the
collet.
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