DATSUN B110 1973 Service Repair Manual

ENGINE
MECHANICAL

GENERAL
DESCRIPTION

CONTENTS

ENGINE

CYLINDER
BLOCK

CRAN
KSHAFT

PISTON
AND
CONNECTING
ROD

CYLINDER
HEAD
EM

EM
2

EM
2

EM
2

EM
2
CAMSHAFT

VALVE
MECHANISM

CAMSHAFT
DRIVE

MANIFOLD
EM

3

EM
3

EM
3

EM
3

ENGINE

The
AI2

engine
is
a
1
171
cc
71
5
cu

in
in
line
over

head
valve

four

cylinder
engine
with
73
mm

2
874
in

bore
and
70
mm
2
756
in
stroke
It
feature

full

opened
wedge
shaped
combustion

chamber
aluminum

heads
and

fully
balanced
5

bearing
crankshaft

to
turn
out

smooth

dependable
power

c

Ii

I
l

1

nun

y
r

r

Fig
EM
t

Sectional
view

of
At2

Engine

EM
1

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
MECHANICAL

I

I
J

I

v

Fig
EM
13

Engine
on

engine
stand
DISASSEMBLY

1
Mount

engine
assembly
on

engine
stand

I
Remove
the

engine
mounting
bracket
R
H

2
Install
the

engine
attachment

3
Mount
the

engine
on
the

stand

Engine
stand

ST050
10000

Engine
attachment

ST05270000

2
Remove
the
alternator

and

engine
mounting
bracket

L
H
side

3
Remove
the

crankshaft

pulley

4
Remove

the
oil

pump
together
with

the
oil
ftIter

Fig
EM
14

Oil

pump
removal
5
Remove
the

high
tension
cable
with
the

distributor

cap
on

6
Remove
the

spark
plugs

7
Remove
the

distributor

assembly

8
Remove

the
carburetor

9
Remove

the
rocker
cover

10
Remove

the
thermostat
housing

Fig
EM
15

Thermostat

housing
removal

I
L
Remove

the
manifolds

Fig
EM
16

Manifolds
removal

12
Remove

the
water

pump

EM
5

ENGINE

l
JJ

l

Ii

Fig
EM
t7
Water

pump
r
1

13
Remove
the

fuel

pump

14
Remove
the

rocker
shaft

assembly
and

push
rods

Fig
EM
18

Rocker

shaft
assembly
removal

IS
Remove
the

cylinder
head

assembly

Fig
EM
19

Cylinder
head
bolts
removal

sequence
16
Invert
the

engine

17

Remove
the
oil

pan
and
oil
strainer

Fig
EM
20

Oil
stromer
removal

18
Remove
the

timing
chain
cover
and
the
chain

tensioner

19

Remove
the
crankshaft
and
camshaft

sprockets

together
with
the

timing
chain

Fig
EM
21

Timing
chain
cover
removal

20
Rotate
the

engine
a

quarter
turn
and
remove
the

piston
and

connecting
rod

assembly
Take
off
the
con

necting
rod

bearings
at
the
same
time
and

keep
them
in

order

EM
6

ENGINE
MECHANICAL

Fig
EM
22

Piston
and

conMcting
rod

assembly
removal

21
Rotate
the

engine
a

quarter
turn
and
remove
the

flywheeL

22
Remove

the
main

bearing
cap
and

the
rear
oil
seal

Fig
EM
2J

Rear
oil
seal
removal

23
Remove
the

crankshaft

24
Remove

the
baffie

plate
and

the
crank
case
net

Fig
EM
24

Baffle

plate
and
net
removal
25

Remove
the
camshaft
after

taking
ofT
the
camshaft

plate

Fig
EM
25

Camshaft
plate
removal

26
Remove
the

valve
lifter

PISTON
AND

CONNECTING

ROD

1
Remove
the

piston
rings
with
a

ring
remover

2

Press
out
the

piston
pin
with
a

piston
pin
remover

and
an

arbor

press

Piston

pin
press
oland
STl3040000

ST13040000

EM103

Fig
EM

26
Piston

pin
removal

CYLINDER

HEAD

Remove
the

valves

using
a
valve
lifter

Valve
lifter
STl2070000

EM

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

2
The
valve
face

or
valve
stem
end
surface
should
be

refaced

by
using
a

valve

grinder

Notes
a
Deflection
of
seat
surface

against
axis
should

be
0
03
mm
0
0012
in
or
less

b
Correctness
of

right
angle
and
out
of
round

should
be
0
01
mm
0
0004
in

or

I

c

EM111

Fig
EM
33

Valve

grinder

Note
When
the
a1ve
head
has
been
reduced
to
0
5
mm

0
0197
in

or

I
in

thickn
replace
the
al

e

Grinding
allowance

for
the
alve

stem
end
surface

is
0
5

mm
10
0197
in

or

I

Valve

spring

I
Measure
the

free

length
and
the
tension
of

each

spring
If
the
measured
value
exceeds
the

specified
limit

replace
the

spring

Spring

specifications

Free

length
46
5
mm
1

831
in

38
7

rom
at
23
9

kg

1
524
in

at
52
7Ib
Valve
closed

Valve

open
30
2
rom
at
58
5

kg

1
19
in
at
1291b

EM
l0
2

Check
each

spring
for
deformation
with
a

square

Any
springs
with

deflection
of
1
6

mm
0

0630
in
or

more
must
be

replaced

EM113

Fig
EM

34
Valve

spring
test

Valve
rocker
shaft
and
rocker
arm

I

Check
the
valve

rocker
shaft
and
rocker
arm
for

seizure
and
wear
and

repair
or

replace
as

required

Valve
rocker
arm
to
shaft
oil
clearance

0
02
to
0
05

mm
0
0008
to
0
0020
in

2

When
valve

contact
surface
of
the
valve
rocker
arm
is

worn

excessively
in

step
repair
by
means
of
a
valve

grinder
or
replace

Grinding
allowance
for
valve
contact
surface
of
the

valve
rocker
arm
is
0
5
rom
0
0197
in

or
less

t

Fig
EM

3S

val
Tocker

shaft