lock DATSUN B110 1973 Service Repair Manual

ENGINE

CYLINDER
BLOCK

The

cylinder
block
in

a
mono
block

special
casting

structure

adopts
five

bearing

support
system

The
A
12

Engine
is

provided
with

baffle

plate
and
steel

net
to

reduce
oil

consumption
the
steel
net

scoops
oil

j
y

r

0

Q

0

T

Fig
EM
2

Cylinder
block

Fig
EM
3

Cylinder
block

CRANKSHAFT

The
crankshaft
is
made
of

special
forged
steel
and

provided
with

a
high

capacity
balance

weight
The

crankshaft

improves
engine
quietness
and

durability
t

high
speed
operation

The
main

bearing
are
lubricated
from
oil
holes
which

intersect
the
main
oil

gallery
in

parallel
with
the

cylinder

bores
v

Fig
EM
4

Crankshaft

PISTON
AND
CONNECTING
ROD

The

newly
designed
lightweight
piston
is

of
cast

aluminum

slipper
skirt

type

The
A
12

Engine
uses
concave
head

pistons
The

piston

pin
is
of
a

special
steel
hollow

type
and
is
connected
to

the

piston
in

a
full

floating
fit
and

to
the

connecting
rod

in

press
fit

The

connecting
rod
is

made
of

forged
steeL
Full

pressure
lubrication
is

directed
to
the

connecting
rods

through
drilled
oil

passages
from
the

adjacent
main

bearing

journal

Oil
holes

on
the

connecting
rod

journals
are
designed

so

that
oil
is

supplied
to

give
maximum
lubrication

just

before
full

bearing
load
is

applied

J

oO

o

e

Fig
EM
5
Piston
and

connecting
rod

CYLINDER
HEAD

The

cylinder
head
is

made
of

light
and

strong

aluminum

alloy
with

good
cooling
efficiency
A

special

aluminum
bronze
valve
seat
is
used
on
the
intake
valve

while

a

special
cast
valve
seat
is
installed
on
the
exhaust

valve
These

parts
are
hot

press
fitted

EM
2

ENGINE
MECHANICAL

Fig
EM
6

Cylinder
head

CAMSHAFT

Camshaft
is
made
of

special
cast
iron

and

supported
by

five
cannshaft

bearings

1

1

f

r

f

r

I

Fig
EM

Camshaft

Camshaft

bearings
are

lubricated
from
oil

holes
which

intersect
the
main

oil

gallery
of

the

cylinder
block

Concentric

passages
are
drilled
in

the
front
and
rear

parts
of
the

camshaft
for

supplying
oil
to
each

cam
lobe

through
an

oil
hole

drilled
in
the
base

circle
of
each
lobe

Lubricant
is

supplied
to
the
front

oil

gallery
from
2nd

camshaft

bearing
and
to
the

rear
oil

gallery
from
4th

camshaft

bearing

From
the
center
camshaft

bearing
lubricant
is

supplied

to
the
valve
rocker
shaft

through
the
center
locker
shaft

bracket

VALVE
MECHANISM

The
valve

system
has

push
rod

type
rocker
arm
which

uses
the

single
type
valve

springs
a

Fig
EM
8

Vol
mechanism

CAMSHAFT
DRIVE

The
camshaft
is

driven
with
a
double
row

roller
chain

which

is
driven

by
the
crankshaft

Tension

of
the

chain
is
controlled

by
the
chain

tensioner

which
is

operated
with

spring
and
oil

pressure

The
rubber

shoe

type
tensioner

insulates
vibration
of

the
chain
and
controls
tension

of
the

chain

Fig
EM
9

Comshdft
drive
chain

MANIFOLD

The
intake

manifold
is
a
mono

block
aluminum
cast

The

exhaust
manifold
is

made
of

a
cast
iron
The

semi

dual
exhaust

system
which
combines
exhaust

gas

flow
at
the

point
of
exhaust

pipe
connection

improves

exhausting
efficiency

The
exhaust
manifold
has

a
heat
control

valve
which

assures
stable

and
smooth

engine

running
after

starting

during
cold

season
The
manifold

is
connected
to
the

exhaust

pipe
by

flanges
which

completely
eliminate

exhaust

leaking

EM
3

ENGINE

Fig
EM
IO
Intake

manifold

Fig
EM
12
Intake

and
exhaust

manifolds

Fig
EM
It
Exhaust

manifold

ENGINE
DISASSEMBLY

CONTENTS

CLEANING
AND

INSPECTION

DISASSEMBL
Y
EM
4

EM
5
PISTON
AND
CONNECTING
ROD

CYLINDER
HEAD
EM
7

EM
7

CLEANING
AND
INSPECTION
breakage
rust

damage
and
loss

Clean
the

engine
thoroughly
before
disassembly

Before

cleaning
the

engine
remove
the
electrical

parts

and

plug
up
the
carburetor
air
horn
to
avoid
intrusio
n
of

foreign
matter
2

Cylinder
block

Check

thoroughly
the

water

jacket

for
cracks
and

breakage

3
Clutch

howing
Check
for
cracks

1
The

engine
exterior
Check
the

covers
and
bolts
for
4

Oil

pan
Check
for
excessive
rust

EM
4

ENGINE

J

I
r
I

I
J

fj

7
L

j
8

if

d1
I

ilfi
3

c

7

I
t

j

v

1

Ji

Fig
EM
27

Valve
mo
1

2
Be
careful
not
to
lose
valve

spring
seat
oil
seal
valve
collet
and
valve
rocker

spring

O

tj
AAAftIl

C

e
WWII

o

glAWle

Fig
EM
28

Valve

components

INSPECTION
AND
REPAIR

CONTENTS

PREPARATION
FOR
INSPECTION
EM
8

How
to
measure
cylinder
bore

EM
16

CYLlNOER
HEAD
AND

80ring
cylinder
EM
16

VALVES

EM
9

PISTON
PISTON
PIN
AND

Checking
cylinder
head

mating
face
EM
9

PISTON
RING

EM
18

Valve

assembly
EM
9

CONNECTING
ROD

EM
19

Valve

spring
EM
10
CRANKSHAFT
EM

20

Valve
rocker
shaft
and
rockei
arms

EM
lO
BUSHINGS
AND
BEARINGS

EM

21

Valve
lifter

and

push
rud

EM
11

Measuring
main

bearing
clearance

EM
21

Valve

guide
EM
11

Measuring
connecting
rod

bearing
clearance

EM
22

Valve
seat
inserts

EM
12

Fitting
crankshaft
bearings
EM
22

CAMSHAFT
AND

CAMSHAFT
BEARINGS
EM
14

Fitting
camshaft

bushings
EM
23

Measuring
camshaft

bearing
clearance

EM
14

MISCELLANEOUS
COMPONENTS
EM

24

Valve

timing
EM
14
Crankshaft

sprocket
and
camshaft

Checking
camshaft
for

bending
EM
14

sprocket
EM

24

CYLlNOER
BLOCK
EM
15

Flywheel
EM

25

PREPARATION
FOR
INSPECTION

L

Check
the

cylinder
head
and

cylinder
block
for

traces

of
water
leaks
before

cleaning

2

Clean
all

parts
to
remove
oil
stains
carbon

deposits
fur
and
other

foreign
matters

completely

3
Make

sure
that
all
oil
holes
are
clear
Blow
air
into

them
if

required

4

Secure

proper
assembly
carefully

EM
8

ENGINE
MECHANICAL

CYLINDER
HEAD
AND

VALVES

Checking
cylinder
head

mating
face

Fig
EMc29

Cylinder
head

I

Visually
check
for
cracks
and
flaws

2

Measure
the

surface
of
the

cylinder
head
on
the

cylinder
block
side
for

warping
If
it
exceeds
the
limit

indicated
below

regrind
affected
surface
with

a
surface

grinder

Cylinder
head
surface
flatness

Standard
Maximum

rom
in

mm
in

AI2

Engine
less
than
0
1

O
OS

0
0020
0

0039

t

C

in

00

co

0

00

2

0
Sco

co
0

0

i

Q
coco

a
ilt

BE

mIX

2
00

5

3YI
I

35
0
to
35
2
dia

1

378
to
1
3861

INTAKE
Fig
EM
30

Checking
the

cylinder
head

surface

Valve

a88embly

I

Check
each
of

the
intake
and

exhaust
valve
asc

semblies
for
wom

damaged
or
deformed
valve

caps
and

stems

Correct
or

replace
the
valve
if

required

l

EM110

Fig
EM
31

Chuking
valve
stem
diameter

t

L

coco

CO

co

BE
Ln

oq
q

od

M

2
g

tOo

18co1
O
c

0

DO

o

0

0

co

o
CO

co

J00

45
30

1
I

I

2
9
0
t
29

2
dia

1
142
to
1
l501

EXHAUST

UNIT

mm
in

Fig
EM
32

The
intake
and
exhaust

valves

EM
9

ENGINE
MECHANICAL

Valve
lifter
and

push
rod

L
Check
the
valve

lifter
for
wear
seizure

and
bevel

edge

contact
and

repair
or

replace
as

required

2
Measure

clearance
between
the
lifter
hole
on
the

cylinder
block
and
valve

lifter
and

replace
the
valve
lifter

when
clearance
exceeds
the
limit

Standard

rom
in
Maximum

rom
in

Valve
lifter

lifter
hole

clearance
0
02
to

0
05

0
0008
to
0
0020
0
15

0
0059

3

Check
the

push
rod
for

bending
and

damage
and

repair
or

replace
as

required

Valve

guide

Measure

clearance
between
the
valve

guide
and
valve

stem
If
clearance
exceeds
the

designated
limit

replace
the

worn

parts
or
both
valve
and
valve

guide
In

this
case
it
is

essential
to
determine
if

such
a
clearance
has
been
caused

by
a
worn
or
bent
valve

stem
or

by
a

worn
valve

guide

EXHAUST
8

3
to
8
5
dill

03266
to

T

3

10
11S11

I

FITTING
SIDE
iD

o

0

co

0

o

c

o
LOt

0
0

0

a

9

ll
l
INTAKE

1S
5

o
O
726

5312
0771
iO

0

N

0

00

E

2

UNIT
mm

in

Fig
EM

J6
Standard
valve

guide
In
valve
Ex
valve

Stem
to

guide

clearance

rom
in
0
Dl
5

to
0

045

0
0006
to

0

0018
0

040
to
0

070

0

0016
to

0

0028

Maximum

tolerance

of

above
clearance

rom
in
o
I

0

0039
0
1
0
0039

Determining
clearance

When

measuring
clearance
between
the

valve
stem
and

the
valve

guide
accurately
aids

of
a

micrometer
and

telescopic
hole

gauge
are

required
By
using
these

gauges
measure
diameter
of
the
valve
stem
in

three

places
top
center
and
bottom
Insert
the

telescopic

h
le

gauge
into

the
valve

guide
bore
and

measure
at

the
center
Subtract

highest
reading
of
valve
stem

diameter

from
valve

guide
bore
to

obtain
valve
to
valve

guide
clearance
As

a

simple
method

push
the
valve

into

the
valve

guide
and

move
to
the

left
and

right
At

which

points
if
the

tip
deflects
about
0
2

mm
0

0079

ir

or

more
it
will
be
known
that
clearance
between

the
stem
and

guide
exceeds
the
maximum

limit
of

0
1

mm
0

0039
in

Note
The
valve
should
move
in

parallel
with
the
rocker

arm

Generally
a

large
amoul
t
of
wear
occurs
in

this
direction
l

Replacement
of
valve

guide

When
a
defective
valve

guide
is
found

replace
it
in

accordance
with
the

following
instructions

I
Remove

the
defective

guide
by
means
of
a

press
and

drift

pin
under

a
2
ton

pressure
This
work

may
be

carried
out
at
normal

room

temperature
however
the

work
can
be
carried
out

more

effectively
at

higher

temperature

2
Ream

cylinder
head
side

guide
hole
at
nonnal
room

temperature

EM
l1

ENGINE

CAMSHAFT
AND
CAMSHAFT

BEARING

Measuring
camshaft

bearing
clearance

Measure

inner
diameter
of
the
camshaft

bearing
and

outer
diameter
of
the

camshaft

journaL

If
camshaft

bearing
clearance
is
excessive

replace
the

cylinder
block

assembly

Limit
0
15mm
0
0059
in

Standard
o
oi
to
0
07mm

M012
to
0

0627
in

Fig
EM
42

Camshaft
bearing
check

1st

2nd

Oil

clearance

mm
in
3rd

4th

5th

1st

Inner

I
2nd

I

diameter
of

I

I
camshaft

3rd

bearing

mm
in

14th
I

15th
I
Standard

0
037

to
0
060

0
0015

to
0
0024

0
027
to
0

050

0
00

to
0
0020

0
040
to

0
063

0
0016
to
0

0025

0
027
to

0
050

0
0011
to

0
0020

0
037
to

0
060

0

0015
to
0
0024

43
833
to
43

843

i

7257
to
I
7261

43
323

to
43
333

l
7050
to
1
7060

42
836
to

42
846

1

6865
to
1
6868

42
323

to
42
333

1
6663
to

1
6667

41
258
to
41
268

1

6243
to

1
6247
Wear
limit

0
15

0
0059

1

1

1

1
Valve

timing

If

the
camshaft
has

no
apparent
damage
although
some

valve
troubles
have
been
detected

compare
valve

timing

data
with

the
valve

timing
diagram
to
ensure
that

beginning
and

ending
of
stroke
for
all

cylinden
are

complying
with

specified
advance
and
retard

figures

T
D
C

DIRECTION
OF

ROTATION

INTAKE

B
D
C

Fig
EM
43
Valve

timing
diagram

Unit

degree

a
b
e
f
d
c

248
248
14
54
12

56

Checking
camshaft
for

bending

Check
the
camshaft
camshaft

journal
and
cam

surface
for
bend
wear
or

damage

If
defective
condition
exceeds
the
limit

replace
the

defective

part
s

2

Apply
a
dial

gauge
to
the
center

journal
turn
the

camshaft
and
read
the
dial

gauge
Actual

bend
is
a

half
of

the
value
indicated
on
the

dial

gauge

Standard
Bend
limit

Camshaft
bend

mm
in
0
015
0
0006
0
05
0
0020

EM
14

ENGINE
MECHANICAL

Bendin9
limit
0
05mm
0
0020
in

Standard
0
of5mm
0
0006
in

or
less

Fig
EM
44

Camshaft
bend
check

Standard

height
of
cam

mm
in
36
45
to
36
55

I
435
to
I
439

Wear

limit
of
cam

height

mm
in
0
5
0
0197

Allowable
difference
in

diame

ter
maximum
worn
and
mini

mum
worn

parts
of
camshaft

journal
mm
in
0
03

to
0
07

0
0012
to
0
0028

Maximum
tolerance
in

journal
diameter

mm
in
0
1

0
0039

Camshaft
end

play

mm
in
0
02

to
0
08

0

0008
to
0

0031

CYLINDER
BLOCK

Check
the

cylinder
head

visually
for
defects
such
as

cracks
and
flaws

2

Measure
the

top
of
the

cylinder
block
cylinder
head

mating
face
for

warping
If
the

warp
exceeds
the
limit

correct
it

EM
15
Standard
Maximum

tolerance

Surface
flatness
less
than

mm
in
0
05
0
0020
0
1
0
0039

Distortion
limit
0
10mm
0
0039
in

Standard
0
05mm
0

0020

inLor
less

Fig
EM
45

Cylinder
block

surface
check

3
Measure
the

cylinder
bore
for
out
of
round
and
wear

with
a
bore

gauge
If
wear
or
out
of
round
is
excessive

rebore
the

cylinder
walls

by
means
of
a

boring
machine

Wear
limit
0
2mm

0

0079

Fig
EM
46

Measuring
the

cylinder
bore

4
When
wear
or

out
of
round
is
minor
and
within
the

limit
remove
the

step
from
the

topmost
portion
of

the

cylinder
by
the
use

of
a

ridge
reamer
or
other
similar
tooL

ENGINE
MECHANICAL

5

M

co

El

co

I

ED

I

UNIT
mm

in

Fig
EM
49

Measuring
points

Outer
diameter
of

piston
skirt
measured
value

A

Piston
eylinder
clearance

B
0
023

to
0
043

mm
0

0009
to
0
0017
in

Boring
allowance
C
0
02

rom
0
0008
in

Cylinder
bore
to
be

machined

A
B
C
A

om
to
0
02
mm

0
0004
to
0

0008
in

4

Machine
the

cylinder
bore
to

the
determined
inner

diameter

Note
To

prevent
strain
due
to

cutting
heat

bore
in

order

of

2
4
3

or
cylinders
3
4
2

5
Do
not
intend
to
bore
in
one
time
but

cut
0
05
rom

0
0020
in

or
so
at

a
time

6
When

measuring
cylinder
bore

immediately
after

boring
note
that
the

cylinder
block
is

expanded
due
to

cutting
heat

7

Finish
the

treated

cylinder
bore
to
the

final
size

by

means
of

honing

8
Measure
the
finished

cylinder
bore
for
a

elliptic
or

tapered
part

9
Measure

clearance
between
the

piston
and

cylinder

This
clearance
can
be
checked

easily
by
using
a

feeler

gauge
and
a

spring
scale

EM
17
Feeler

gauge

0
03mm
0
0012
in

Pull
force

o
5to

5kg

11
to3
3
lb

i

Fig
EM
50

Piston
to

cylinder
clearance
check

Standard

clearance

rom
in
0
023

to
0
043

0
0009
to
0
0017

0

03
0
0012
Feeler

gauge
mm
in

Extracting
force

kg
Ib
0
5
to
1
5

1
1

to
3
3

Note
If
the

cylinder
bore
is
worn

beyond
the
wear
limit

use
the

cylinder
liner

Undersize

cylinder
liners

are
available
for
service

Interference
fit
of

cylinder
liner

Cylinder
block

0
8
to
0
9
mm
0

0315
to
0
0354
in

Cylinder
liner
for

service

400

undersize
Outside
diameter

mm
in

77
05
to

77
00

3

0330

to

3
0310

77
55

to
77
50

3

0530

to

3
0510

78
05

to
78
00

3
0730
to

3

0710
72
5

to
72
6

2

854

to
2
858
Inner
diameter

mm
in

72
5
to
72
6

2
854
to
2
858

450

undersize
72

5
to

72
6

2
854
to
2

858

500

undersize

ENGINE
MECHANICAL

Standard
Maximum

Crankshaft
bend

mm
in
0
05

0

0020
0

015

0

0006

Note

When
measuring
bend
use
a
dial

gauge

Bend
value
is

a
half
of
the
reading
obtained
when

the
crankshaft
is
turned
once
with
the
dial

gauge

applied
to

its
center
journal

3

After
regrinding
the
crankshaft
fmish
it
to
the

necessary
size
indicated
in
the
lists

on

pages
EM
25

by

using
an

adequate
undersize
bearing
according
to
the

extent
of

required
repair

4
Install
the
crankshaft
in
the

cylinder
block
and

measure
the
thrust
clearance

Fig
EM
60

Crankshaft
end

pldy
check

Standard
Limit

Crankshaft
free
end

play
rom

in
0
05
to
0
15

0
0020
to
0
0059
0
30

0
D118

5
Check
the

main
drive
shaft

pilot
bearing
at
the
rear

end
of
the
crankshaft
for
wear
and

damage

Replace
it
if

any
defects
are
detected
BUSHING
AND
BEARING

Measuring
main

bearing

clearance

Check
all

bearings
and

bushings
for
seizure
melt
scar

and

burr

Replace
bushings
if

any
defects
are
detected

2

Wipe
off
oil

and
dust

especially
the
rear
of
the

bushing

3

Set
the
main

bearing
on
the

cap
block

Scale

Plastigage

EM141

Fig
EM
61

Plastigage

4
Cut
a

plastigage
to
the

width
of
the

bearing
and

place

it
in

parallel
with
the
crank

pin
getting
clear

of
the
oil

hole

Install
the

cap
on
the
assembly
and

tighten
them

together
with
the

specified
torque

Tightening
torque

5

0
to
6

0

kg
m
36

to
43

ft
lb

Note
Be

sure
not
to
turn

the
crankshaft
when
the

plastigage
is

inserted

5
Remove
the

cap
and
measure
width
of
the

plastigage

at
its
widest

part
with
the
scale

printed
in
the

plastigage

envelope

EM
21