Defender 90 / 110 / 130. Instruction - page 46
CYLINDER ENGINE
the
wheels complete with timing
6. Measure t h e camshaft journals for overall wear,
ovality and taper. The diameters of the five
journals are as follows commencing from the front
of the shaft.
chain.
3. Withdraw
camshaft whilst
particular
not
to
bearings
in
t h e
cylinder
block.
\
...
,
....
.
.
Examine components
4.
Visually examine all parts
for wear. Check t h e
camshaft bearing journals and cams
for wcar, pits,
scores and overheating. Should any of these
conditions
present the shaft should be renewed.
5. Examine the links and pins of the timing chain
for
wcar and compare its condition with that of
a
chain. Similarly the
of
t h e
chain wheels
should be inspected
a n d
i f
necessary the wheels
should be renewed.
Number 1 journal 1.786 to 1.785 ins
Number journal
to 1.755 ins
Number
3 journal 1.726 to
ins
Number 4 journal 1.696 to 1.695 ins
Number
5 journal 1.666
to 1.665 ins
7.
To check the camshaft for bow, rest the two end
journals i.e.
1
and
5
on ‘V’ blocks and
mount a dial gauge
on the centre journal. Rotate
t h e
shaft and note the reading.
If
the run
out is
more than
(0.002 in)
it
should be
renewed.
REMOVE AND OVERHAUL CONNECTING-RODS
AND
PISTONS
1.
Withdraw the remaining bolts and remove
2. Remove the sump oil strainer.
3.
the connccting-rod caps and retain them
in
sequence for reassembly.
4.
Screw the guide bolts
605351 onto the connecting-
rods.
sump.
continued
103
V8
CYLINDER ENGINE
5 .
Push the connecting-rod and piston assembly up
the cylinder bore and withdraw it from the top.
Retain the connecting-rod and piston assemblies
in
sequence with their respective caps.
6.
Remove the guide bolts
605351 from the
connecting-rod.
Overhaul
NOTE: The connecting-rods, caps and bearing shells
must be retained in sets, and in the correct sequence.
Remove the piston rings over the crown
of the piston. If
the same piston is
to
be refitted, mark it relative to its
connecting-rod to ensure that the original assembly is
maintained.
7. Withdraw the gudgeon pin, using tool
1150 as
follows:
a. Clamp the hexagon body
of 18G
in a vice.
Position the large nut flush with the
of the
c. Push the screw forward until
nut
contacts the
centre scrcw.
thrust race.
104
Locate the piston adaptor
1150
E
with its
long spigot inside the bore of the hexagon body.
e .
Fit the
bush of
1150
on
the centre screw with the flanged end away
from
the gudgeon pin.
f. Screw the stop-nut about half-way onto the
smaller threaded end of the centre screw,
leaving
a gap ‘A’ of 3
in) between this nut
and the
bush.
g. Lock the stop-nut securely with the lock screw.
h. Check that the remover-replacer bush is
correctly positioned in the bore
of the piston.
Push the connecting-rod to the right to expose
the end
of the gudgeon pin, which must be
located in the end
of the adaptor
Screw the large nut
up to the thrust race.
k.
Hold the lock screw and turn the large nut until
the gudgeon pin has been withdrawn from the
piston. Dismantle the tool.
continued
d
a
c
b !
CYLINDER ENGINE
8.
As an alternative to tool
18G
1150, press the
gudgeon pin from the piston using an hydraulic
press and the components which comprise tool
605350
as
follows:
a. Place the base
of
tool
605350 on the bed of an
hydraulic press which has a capacity
of
8
tons
(8
tonnes).
Fit
the guide tube into the bore
of the base with
its countersunk face uppermost.
c. Push the piston to one side
so as to expose
one
end of the gudgeon pin and locate this end i n the
guide tube.
Fit
the spigot end of the small diameter mandrel
into the gudgeon pin.
e. Press out the gudgeon pin, using the hydraulic
press.
.
...
.
....
E
pistons
Pistons are available
in service standard
and
in
oversizes of
(0.010 in) and
(0.020
in). Service standard size pistons are
supplied
0,0254
in) oversize. When
..fitting new service standard size pistons to
a
cylinder block, check
for correct piston to bore
clearance, honing the bore if necessary. Bottom of
piston skirt-bore clearance should be
0,018 to
0,033
(0.0007
to
0.0013 in).
NOTE: The temperature
of the piston and cylinder
block must be the same to ensure accurate
measurement. When reboring the cylinder block,
the crankshaft main bearing caps
must be fitted and
tightened to the correct torque.
9. Check the cylinder bore dimension at right angles
to
the gudgeon pin,
40
50
to 2 in) from
the top.
10. Check the piston dimension at right angles to the
gudgeon pin, at the bottom of the skirt.
11. T h e piston dimension must be
0,018 to 0,033
(0.0007
to
0.0013 in) smaller than the cylinder.
12. If new piston rings arc to be fitted without
reboring, deglaze the cylinder walls with
a hone,
without
the bore diameter to provide a
cross-hatch finish.
Original pistons
Remove the carbon deposits, particularly from the
ring grooves.
Examine t h e pistons
for signs
of
damage
or
excessive wear;
to 'new pistons' for the
pistons
if necessary.
"I
continued
105
V8
CYLINDER
ENGINE
13.
Check the compression ring gaps in the applicable
cylinder,
square to
bore with
piston.
Gap limits:
to
(0.017 to 0.022 in).
Use
a fine-cut flat file
to
increase the gap if
required. Select a new piston ring if the gap
exceeds the limit.
NOTE:
does not apply
to oil control rings.
Fit piston rings
17.
Fit
expander ring into the bottom groove
making sure that
the
ends butt and do not overlap.
18. Fit two ring rails to the bottom groove, one above
and one
expander ring.
19. Fit the second compression ring
with
the marking
‘TOP’ uppermost and the chrome
ring
in
top
groove, either way round.
14. Temporarily fit the compression rings to the piston.
15. The ring marked
‘TOP’ must be
with the
marking uppermost and into t h e second groove.
The chrome ring is for t h e top groove and can be
fitted either way round.
Check the compression
ring clearance in the piston
groove.
limits:
to
to
0.004 in).
20. Check the alignment of the connecting-rod.
21. Check the connecting-rod small end, the gudgeon
pin must be press
f i t .
106