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

							ENGINE
4
OVERHAUL 5.Clean gasket surface in rocker cover.
NOTE: Gaskets fitted to early engines
were manufactured from cork whilst those
fitted to later engines are manufactured
from rubber. The later type gaskets should be
fitted as replacements to all engines. Cork
gaskets were retained by an adhesive whereas
rubber gaskets do not need an adhesive. If cork
gaskets were originally fitted, remove all traces
of adhesive using Bostik Cleaner 6001 or
equivalent.
6.Fit new gasket, dry to rocker cover.
7.Fit rocker cover to cylinder head, fit bolts and
tighten in diagonal sequence to:
Stage 1 - 4 Nm (3 lbf.ft)
Stage 2 - 8 Nm (6 lbf.ft)
Stage 3 - Re-torque to 8 Nm (6 lbf.ft)
CAUTION: The 2 short bolts must be fitted
on side of cover nearest centre of engine.
8.
LH rocker shaft only:Align dipstick tube to
rocker cover, fit and tighten screw.CYLINDER HEAD
Cylinder head - remove
1.Remove rocker shaft assembly.
2.Mark heads LH and RH for reassembly.
NOTE: RH cylinder head illustrated.
3.Using sequence shown, remove and discard
10 bolts securing cylinder head to cylinder
block.
4.Release cylinder head from 2 dowels and
remove cylinder head.
5.Remove and discard cylinder head gasket.
6.Repeat above procedures for remaining
cylinder head. 
						

							ENGINE
OVERHAUL5
Valves and springs - remove
1.Remove spark plugs.
2.Using valve spring compressorLRT-12-034or
a suitable alternative, compress valve spring.
3.Compress valve spring sufficiently to release
collets from valve spring cap.
4.Release spring compressor and remove
collets, valve, valve spring cap and valve
spring.
5.Repeat above operations for remaining valves.
NOTE: Keep valves, springs, caps and
collets in fitted order.
6.Remove and discard valve stem oil seals.Cylinder head - inspection
1.Clean all traces of gasket material from
cylinder head using a plastic scraper.
2.Check core plugs for signs of leakage and
corrosion, replace as necessary. Apply Loctite
572 to threads of screwed core plugs.
3.Check gasket face of each cylinder head for
warping, across centre and from corner to
corner.
Maximum warp = 0.05 mm (0.002 in) 
						

							ENGINE
6
OVERHAUL
4.Check cylinder head height at each end of
cylinder head:
A= 22.94 mm (0.903 in) - New
B= 62.56 mm (2.463 in) - New
5.Cylinder heads may be refaced:
Reface limit = 0.50 mm (0.02 in) from new
dimensionValves, valve springs and guides - inspectionNOTE: Two types of exhaust valve may be
fitted - standard valves A in illustration or
carbon break valves - B in illustration.
Carbon break valves may be identified by the
machined profile C on the valve stem. To prevent
exhaust valves sticking, standard exhaust valves
should be replaced with carbon break valves
during engine overhaul. 
						

							ENGINE
OVERHAUL7
1.Remove carbon deposits from valve guides
using an 8.70 mm (0.34 in) diameter reamer
inserted from combustion face side of cylinder
head.
2.Clean valve springs, cotters, caps and valves.
Clean inlet valve guide bores. Ensure all loose
particles of carbon are removed on completion.
3.Check existing valve stem and head diameters.
4.Check valve stem to guide clearance using
new valves.
5.Renew valves and guides as necessary. Valve
head diameterA:
Inlet = 39.75 to 40.00 mm (1.5 to 1.6 in)
Exhaust = 34.226 to 34.48 mm (1.3 to 1.4 in)
Valve stem diameterB:
Inlet = 8.664 to 8.679 mm (0.341 to 0.342 in)
Exhaust = 8.651 to 8.666 mm (0.340 to 0.341
in)
6.Check installed height of each valve.
Valve installed heightC= 47.63 mm (1.9 in)
7.Renew valve/valve seat insert as necessary.
8.Check valve stem to guide clearance.
Valve stem to guide clearanceD:
Inlet = 0.025 to 0.066 mm (0.001 to 0.002 in)
Exhaust = 0.038 to 0.078 mm (0.0015 to 0.003
in) 
						

							ENGINE
8
OVERHAUL 9.Check condition of valve springs:
Free length = 48.30 mm (1.90 in)
Fitted length = 40.40 mm (1.60 in)
Load - valve closed = 339±10 N (76±2 lbf)
Load - valve open = 736±10 N (165±2 lbf)
NOTE: Valve springs must be replaced as
a complete set.Valve guides - renew
1.Using valve guide remover,LRT-12-037press
valve guide out into combustion face side of
cylinder head.
NOTE: Service valve guides are 0.025 mm
(0.001 in) oversize on outside diameter to
ensure interference fit.
2.Lubricate new valve guide with engine oil and
place in position. 
						

							ENGINE
OVERHAUL9
3.UsingLRT-12-038partially press guide into
cylinder head, remove tool.
4.FitLRT-12-515over valve guide and continue
to press guide into cylinder head until tool
LRT-12-038contacts toolLRT-12-515;
remove tool.
Valve guide installed heightA= 15.0 mm
(0.590 in)
5.Ream valve guides to 8.70 mm (0.34 in)
diameter.
6.Remove all traces of swarf on completion.Valve seat inserts - inspection
1.Check valve seat inserts for pitting, burning
and wear. Replace inserts as necessary. 
						

							ENGINE
10
OVERHAUL Valve seat inserts - renew
NOTE: Service valve seat inserts are
available 0.025 mm (0.001 in) oversize on
outside diameter to ensure interference fit.
1.Remove worn valve seats.
CAUTION: Take care not to damage
counterbore in cylinder head.
2.Heat cylinder head evenly to approximately
120°C (250°F).
WARNING: Handle hot cylinder head with
care.
3.Using a suitable mandrel, press new insert fully
into counterbore.
4.Allow cylinder head to air cool.Valve seats and seat inserts - refacing
CAUTION: Renew worn valve guides and
seat inserts before lapping valves to their
seats.
1.Check condition of valve seats and valves that
are to be re-used.
2.Remove carbon from valve seats.
3.Reface valves as necessary. If a valve has to
be ground to a knife-edge to obtain a true seat,
fit a new valve.
Valve seating face angleA=45° 
						

							ENGINE
OVERHAUL11
4.Cut valve seats usingLRT-12-501with
LRT-12-503andLRT-12-517.
Valve seat:
WidthA:
Inlet = 36.83 mm (1.45 in)
Exhaust = 31.50 mm (1.24 in)
Seating widthB:
Inlet = 0.89 to 1.4 mm (0.035 to 0.055 in)
Exhaust = 1.32 to 1.83 mm (0.052 to 0.072 in)
AngleC=56°to 70°
AngleD=46°to 46°25
AngleE=20°
5.Ensure cutter blades are correctly fitted to
cutter head with angled end of blade
downwards, facing work, as illustrated. Check
that cutter blades are adjusted so that middle
of blade contacts area of material to be cut.
Use light pressure and remove only minimum
of material necessary.
6.Remove all traces of swarf on completion. 
						

							ENGINE
12
OVERHAUL Valves - lapping-in
1.Lap each valve to its seat using fine grinding
paste.
2.Clean valve and seat.
3.Coat valve seat with a small quantity of
engineers blue, insert valve and press it into
position several times without rotating. Remove
valve and check for even and central seating.
Seating position shown by engineers blue
should be in centre of valve face.
4.Check valve installed height if valve seats have
been recut or new valves or valve seat inserts
have been fitted.
Valve installed heightA= 47.63 mm (1.9 in) -
maximum
5.Thoroughly clean cylinder head, blow out
oilways and coolant passages.Valves and springs - refit
1.Fit new valve stem oil seals, lubricate valve
stems, fit valves, valve springs and caps,
compress valve springs usingLRT-12-034
and fit collets.
2.Using a wooden dowel and mallet, lightly tap
each valve stem two or three times to seat
valve cap and collets.
3.Fit spark plugs and tighten to 20 Nm (15 lbf.ft). 
						

							ENGINE
OVERHAUL13
Cylinder head - refit
1.Clean cylinder block and cylinder head faces
using suitable gasket removal spray and a
plastic scraper.
2.Eensure that bolt holes in cylinder block are
clean and dry.
CAUTION: Do not use metal scraper or
machined surfaces may be damaged.
3.Fit cylinder head gasket with the word TOP
uppermost.
NOTE: Gasket must be fitted dry.
4.Carefully fit cylinder head and locate on
dowels.5.Lightly oil threads of new cylinder head bolts.
NOTE: RH cylinder head illustrated.
6.Fit new cylinder head bolts:
Long bolts: 1, 3 and 5
Short bolts: 2, 4, 6, 7, 8, 9 and 10
7.Using sequence shown, tighten cylinder head
bolts to:
Stage 1 - 20 Nm (15 lbf.ft)
Stage 2 - 90 degrees
Stage 3 - Further 90 degrees
CAUTION: Do not tighten bolts 180°in one
operation.
8.Fit rocker shaft assembly.
9.Repeat above procedures for remaining
cylinder head.