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

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