1968 DATSUN 510 check engine

ENGINE
47

allowable

warpage
IS
0
0039
in
0
I
mm

Standard
should
be
less
than
0
0012
in

O
03mm
In
the
event
the
measurements
are

out
of
tolerance
the

cylmder
head
surface

should
be
milled

or
resurfaced

3

Verify
that
all
water
and
011

passages
are
free

of

foreign
matena

Use

compressed
aIr
to
clean

passages
after

scraping

4
Note
the
condition
of
all
studs
in
the

cylinder

head

Replace
damaged
ones

Valve

Assembly

I
Check
intake
and
exhaust
valve
assembhes

for
worn

damaged
or
deformed
valve

caps
and

stems
Correct
or

replace
the
valve
If
excessive

defects
exist

2
Measure
valve
stem
diameter
WIth
a
micro

meter
as
shown
in

Fignre
36

Figure
37

gives

cnncal
drmensions

@

@

Y

lm

1

0
515

r

3
Reface
the
valve
face
and
valve
stem

using
a

valve

grinder
as
18
shown
in

Fignre
38
NOTE

When
the
valve
head

1uzs

been
reduced
to
00197
in
0
Smm

or
less
In
thIckness

replace
the
valve

Grinding
allowance

for
the
valve
stem

end

surface
is
00197
In
0
Smm
or

less

4
Measure
the
free

length
and
tension
of
each

valve

spring
If
the
measured
values
exceed
the

hnuts

specified
below

replace
the

spring

SPRING
SPECIFICATIONS

Free
Length
Outel

Spring

Inner

Spring

Outer

Spring
2
0472
10

52
Omm

1
765710
44
85mm

153m
at6393
331Ib

389mm
at290

15kg

138m
at
2712
154lb

35mm
at12
3
0
7

kg

121
10
at
105
38
5
29
Ib

30
7mm
at
47
8
2
4
kg

09610
at5621
2871b

245mm
at

25
5
13

kg
Valve
Closed

I
nner

Spring

Outer

Spnng

Valve

Open

Inner
Spnng

5
Check
the

deformation
of
each

spnng
with
a

square
Replace
any
spnng
WIth
a
deflection
of

o
063
in
I

611lID
or
more

6
Check
all

workmg
surfaces
of
the
rocker
arms

for

damage
or
wear
If
defects

or

apparent
ex

cessIve
wear

are
found

replace
them
A
defective

PIvot
reqwres
It
S

replacement
along
WIth
the

correspondIng
rocker
ann

7
Measure
the
clearance
between
the

valve

gwde
and
the
valve
stem
If
the
clearance
ex

ceeds
hnuts

replace
the
worn

parts
or
both

ENGINE
49

Cylinder
Block

1
Check
the

cylmder
block
for
defects
such

as

cracks

leaky
soft

plugs
and

blocked
water

pass

ages
Blowout
all

passages
With

compressed
air

2
Measure
the
surface
of
the

cylinder
block

that
mates
with
the

cyhnder
head
for

warpage

Use
a

straight
edge
and
feeler

gauge
to
measure

clearance
as
shown

m

Figure
42
Surface
flat

ness
clearance
should
be
less
than
0
0020
m

0
05mm
Maxunum
allowable
is
0
0039
in

010mm
Resurface
the

cyhnder
block
if

beyond
hnnts

@

3
Use
a

bore

gauge
as
shown
m

Figure
43
to

measure
the
bore
of

each

cyhnder
Measure
near

the

top
at
the
center
and

near
the
bottom
If

excessive
wear

taper
or
out
of
round
exists

rebore
the

cyhnders
or

replace
the

cylinder

hners
Maxunum
wear
hnnt
of
a

cyhnder
bore
IS

o
0079
m
0

2mm
Standard
bore
IS
3
2677

0
0020
m
83
000
0
050mm
The
al

@
lowable
error
m
the

cyhnder
bore

taper
is

0
0006
in
0015mm
The
difference
between

the
four

cyhnder
bores
should
not
exceed
0
0020

in
0
05mm

NOTE
When

any
cylmder
needs
re

boring
all

foUT
must
be
rebored

4
If
the

cyhnder
bores
are
Wlthm
tolerances

use
a

ndge
reamer
to
remove
the

ndge
at
the

top
of
the

cyhnder
bores
and
then
hone
the

cyhnder
walls
to

complete
the

recolllhuonmg

Measure
the

cyhnder
bores
when

honmg
has

been
finished
to

venfy
that
allowable
tolerances

have
not
been
exceeded

Measuring
Bore

Below
is
a
method
for

checking
cntical
clear

ance
between

piston
and

cylinder
wall
Unless

you
are
familiar
With
such

work
call
m
an

expert
Clearance
should
be
between
0
0010
and

0
0018
m
0025

thrQugh
0
045mm

1
Insert
the

pISton
without

rings

upside
down

in
the

cyhnder
bore

2
Use
a
feeler

gauge
between
0
0010
and

00018
mches
thick

Insert
It
between
the

pISton

and
the

cylinder
wall
as
shown

m

Figure
and

attach
a

spring
gauge
as
illustrated

@

ENGINE
51

8

Figure
48
shows
the

pm
bemg
mserted
to

make
certam
that

It
can
be

pressed
m
at
room

temperature
by
hand
Piston

pm
clearance
to

piston
pm
should
be
between
0
0003
and
0
0004

m
0008
and
0
01Omm

NOTE
The

piston
pin
IS

fitted
to
the

connecting
rod
with
a

fitting
force
of

from
1
to
3
tons

of

pressure

Connecting
Rod

1

Inspect
all

connectmg
rods
for
flaws
or

obVIOUS

damage

2
Check
for

proper
alignment
as
shown

m

Fig

ure
49

RealIgn
as

necessary
ThIS
can
be
done

by
an
automotive
maclune

shop
Maxrmum

allowable
bend

m
the

connecting
rods
IS
0
0020

m
0
05mm

per
3
94

m
of

connecting
rod

length

@
3
Defects
m
the

piston
pm
hole

reqwre
replace

ment

of
the

connectmg
rod
Select
new
ones
so

that

weight
dIfference
between
new
and
old
IS

wlthm
0212
oz
6

gr

4
Install

beanngs
m
the
crankshaft
end
of
all

rods
Mount
the
rods
on
the
crankshaft
and

replace
beanngs
and
rod

caps
Install
bolts
and

tighten
Use
a
feeler

gauge
to
measure
end

play

between
the

connecting
rods
and
the
crankshaft

Figure
50
The
standard
measurement
should

be
between
00079
and
0
0118
m
02
and

0
3mm
Maximum
allowable
wear
IS
00118
m

0
3mm

Crankshaft

1
Check
the
crankshaft

journal
and
crank

pm

1
1

for
cracks
obVIOUS
wear
and
scratcheS

Repair

or

replace
defective

parts
I

2
Check
the
crankshaft
for
bend
If
the
bend

at
the
center

Journal
exceeds
0
0020

m

0
05mm
have
the
crankshaft

prOfeSSIOnally

straightened
or

replace
It

3
Check
crankshaft

Journals
and
crank

pms
for

out
of
round
and

taper
Figure
51
lIsts

speci

fications

Regnnd
the
crankshaft
1f
the

specIfica

tions
are
exceeded

by
more
than
00012

m

0
03mm

4

Replace
the

connecting
rod
and
mam
bear

mgs
With

proper
undersIZe

beanngs
If
the
crank

shaft
IS

reground
The

followmg
table

prOVides

data
for

beanng
replacement
based

on
the

final

sIZe
of
the
crankshaft

Journals
and
crank

pIllS

ENGINE
53

the
mam

beanng
cap
and
the

cyhnder
block

beanng
recess
and

tighten
the

cap
bolts
to
the

proper
torque
WIth
a

torque
wrench

Tig
temng

torque

Main

bearings
506
to
57
8
It
Ib

70to80kg
m

195
to
23
9
It
Ib

27
to3
3

kg
m
Rod

beanngs

9
Loosen
the

cap
bolt
on
one
Side
and
measure

the
clearance

Figure
53
between
the

cap
and

block
Side
Clearance
should
be
WIthm
the
fol

lowmg
specmcatIons
Mam

beanngs
0

through

o

0024
m
0
to
0
06mm
rod

beanngs
00012

through
0
0032
m
0
030
to
0
0024mm

Weight
@

10
If

beanng
crush
IS
not
m
tolerance

replace

the

beanngs

Crankshaft
and
Camshaft

Sprockets

1
Check
for

damaged
teeth

Replace
sprocket

1f

necessary

2
Install
the

camshaft

sprocket
and
check
for

runout
as
shown
m

Figure
54
If
over
0
04331

m
0
Imm

replace
the

sprocket
Check
for

thrust
deViation
at
the
same
tIme
Thrust
deVia

tIOn

should
be
between
0
0031
and
0
0150
m

008
to
0
38mm

3
Check
the
chain
for

damage
severe
wear

and
stretch
at
the
roller
hnks

Replace
the
cham

1f
defects
or
exceSSIve
stretch
IS
found

4
Check
the
cham
tenslOner
and
the
cham

gwdes
for
wear
and

damage

Flywheel

1
Check
the
clutch
disc
contact
surface
of
the

flywheel
for
wear
and

damage
@

2

Measure
deviation
of
the
clutch
disc
contact

surface

usmg
a
dial

gauge
If
deVIation
exceeds

004331
m
O
lmm

replace
the

flywheel

3
Check

flywheel
teeth
for

damage
Consult
a

dealer

Or
machIne

shop
1f
m
doubt

ENGINE
ASSEMBLY

This
section
covers

assembly
of
the

engme

after
corrective
mamtenance
has
been
com

pleted
SpecificatIons
and

torque
informatIon

are

given
at
the
end
of
the
sectIon
The

followmg

general
precautions
should
be
followed
m

assembhng
the

engme

1
Make
certam

all

parts
are

thoroughly
clean

and
that
all
011
and
water

passages
are
free
from

foreign
matenal

2
All

parts
that

slIde
mto
or

through
other

parts

should
be
coated
With
a
thm
film
of
new

engme

011
before

assembly

3
Don
t
reuse

gaskets
packIng
and
011
seals

Complete
lats
are
aVlUlable
for
the
entire

engme

and
for
the

cyhnder
head
and
block
assemblIes

4

Keep
tools
and
work
benches
clean
to
aVOid

contammatlon
of
delIcate

parts

5
Be

sure
to
follow

specmed
torque
tIghtenmg

values
and
order

of

tlghtenmg
where

given

6

Unless

complete
rebwld

of
the

engme
has

been
done
valves
and
associated

parts
bear

ings
pistons
and

connectIng
rods
should
be

remstalled
where

they
were
taken
from

CYLINDER

HEAD

Valve
and
Valve

Spring
Assembly

1
Insert
valve
from
bottom
of
block

54

CHAP1ER
SIX

2
Set
the
valve

spnng
seat

m

position
on
the

top
of
the
block
and

over
the

valve
stem

3
Place
the
oil
seal
over
the

valve
stem

4
Place
the

mner
and

outer
valve

spnngs
over

the
valve
stem

S

Place
the

spnng
retamer

over
the

springs

compress
spnngs
With

spring
compressor
Figure

55
and
mstall
valve
collets
around
valve
stem

so
that

they
lock
onto
stem

6
Release

spnng
compressor
If
collets
are
firm

ly
locked
onto
the

groove
m
the

valve
stem

assembly
IS

complete

7
Install
the
rocker

guIde
on

top
of
the

valve

stem
when

assemblmg
the
rocker

pivot
assembly

VaIve
Rocker
Pivot

Assembly

1
Thread
lock
nut
onto
valve
rocker

pivOt
and

place
rocker
retaIner
over
the
valve
rocker

pivOt

2
Thread
the
above

assembly
mto
the
rocker

bushIng
protrudIng
from
the

head

Camshaft

Assembly

1
Mount
the

locatIng
plate
on
the
front
of
the

head
as

shown
m

FJgIlI
1
56

2
From
the
back
of
the
head

carefully
InSert

the
camshaft

through
the

four
camshaft

beanngs

being
ca
efu1
not
to
move
or

damage
the
bear

ings

NOTE
Install
the

CQJ7IShaft

sprocket

onto
the

camshaft
so
that

the
three

locating
holes
are

at
the

top
left
and

bottom
h

1
3

Install
the

camshaft

sprocket
and
fuel

pump

cam
onto

the
front
of
the

camshaft
and

torque

to

specificatIon

4
Check
the
camshaft
for
end

play
using
a

feeler

gauge
as

preViously
described

Rocker
Pivot

Assembly

1
Push
down
on
valve

spnng
with
screwdriver

and
insert
rocker

piVOt
arm
between
camshaft

and
valve
stem

Insert
rocker
valve

guide
onto

top
of

valve
stem

at
this
time

2
Install
valve

rocker

springs
over

top
of
rocker

pivot
arm

Piston
and

Connecting
Rod

Assembly

1

Assemble
the
four

pistons

pms
and
connect

mg
rods
Secure

piston

pm
The

connecting
rod

IS

press
fitted
onto
the

pISton
pin
With
from
1
to

3
tons
of
force

NOTE
The

pistons
are

marked
with

an
F
which

should

point
toward
the

front
of
the

engine
The

connecting

rods

must
be
installed
so

that
the
011

Jet
In
the

large
end

IS

positioned
to

ward
the

right
Side

of
the

tnglne
The

center

of
the

piston
pin
IS

oD
set
In

relation
to
the

center

of
the

piston
so

correct

assembly
is
cntical

2
Use
a

nng
expander
to
install
the

rings
onto

the

pistons
Install
the

top
and
rmddle

nngs

with
the
marks

up

3

Lubncate
the

rod

bearings
hghtly
and
mstall

them
into

their

respective

connectIng
rods
and

rod

caps

ENGINE
55

Cylinder
Block

Assembly

1
PositIon
all
crankshaft

parts
on
a
work
bench

ThIS
mcludes
the
crankshaft
main

beanngs

rear
011

seal
woodruff

keys
crankshaft

gear

011

pump
gear
011
thrower
bolts
and

bearing

caps
Figure
57
shows
the

arrangement

@

2
Insert
maIO

beanngs
mto

appropnate
cy1m

der
block
holders

NOTE
The
center
No
3

beanng
IS

the

only
flanged
type
of
thrust
bear

Ing
Bearings
No
2
and
No
4
are

Identical
No
1
and
No
5

Jaring
ap

pear
identical
but
No
1
as
an
011

hole
All

bearings
except
No
1
are

Interchangeable
as
to

upper
and
lower

half

3

LIghtly
lubncate
the

crankshaft
and

beanng

matmg
surfaces
then
mstall

beanngs
10
mam

beanng
caps

4
Install
the
crankshaft

5
Install
mam

beanng
caps
over

crankshaft

msert
mam

cap
bolts
and

tighten
hghtly
The

mam

beanng
caps
have
an
arrow
marked
on

each
one
These
must

pomt
to
the
front
of
the

engme

6

Gently
move
the
crankshaft
10
an
aXIal
drrec

don

toward
the
front
of
the

engme
to

venfy
that

the
mam

beanng
caps
are

properly
alIgned
and

seated
7
Use
a

torque
wrench
to

tighten
the

cap
bolts

to
the
hmlts

speCIfied
The

t1ghtenmg
operatIon

should
be
done

gradually
10
three

or
four

sep

arate

stages
starting
10
the
center
and

workmg

outward

to
each
end

8
Rotate
the
crankshaft
to
make
certain
it
isn
t

bmding

9
Use
a
feeler

gauge
to
check
the
end

play
at

the
center

No
3

beanng
Figure
58

10
Install
the
SIde
oll
seals
into
the
rear
mam

cap
and

cy1mder
block
as
shown
10

Figure
59

@

11
Install
the
rear
011
seal
WIth
Datsun
tool

ST49370000
or

equIvalent

12
Install
the
rear
end

plate

13
Install
the

flywheel
WIth

proper
bolts
and

lock
washers
and

torque
as

specified

56

CHAPTER
SIX

NOTE
Lubncate
the

cylinder
walls

with
new

engine
oil

prior
to
insertIOn

of
pistOns
Make

certain
that
the

ring

gaps
are
not
In
line

wIth
one
another

Place

the

gaps
180

degrees
from
each

other

and
not

posltloned
either

front

to
back
or

dIrectly
in
line
with

the

piston
pIns

CAUTION

Use
extreme
care
when

Inserting
pzs

tons
so
as
to
avoId

crankshaft

damage

14
With
the
aid
of

a

nng
compressor
illStaIl

the

pISton
and

connectmg
rod
assembhes
into

the

cyhnder
block

as
shown
in

Figure
60
Make

certain
the

proper
piston
IS
mserted
mto
the

proper
hner
and
the
F
on
each

pISton
faces

forward

@

15
Install

beanngs
mto
the

connectIng
rod

caps

after

lubncatmg
them

hghtly

16

Gently
push
connecting
rods
With

beanngs

installed
down
the

cyhnder
until
contact

IS
made

with
the
crankshaft

17
Set

connectIng
rod

caps
over
crankshaft
and

insert

COnnectIng
rod
bolts
Make
certam
that
the

numbers
on
the
rods

and
the
rod

caps
face
in

the
same
direction

18

Tighten
rod
bolts
to
the

proper
torque
speci

ficatIon

as
shown

m

Figure
61

I
J

@v

N

i

19
Check
the

connecting
rod
end

play
With
a

feeler

gauge
as

previously
described

Cylinder
Head
Installation

1

Spread
a
suitable

gasket
seahng
agent
on
the

top
of
the

cylinder
block
and

position
a
new
head

gasket

2

Spread
seahng
agent
on

top
of
the

gasket

CAUTION

PositIon
the

crankshaft
so
that
no

pzston
IS
at

top
dead
center

Before

installing
head

point
the

keys
on
the

camshaft
and

crankshaft

straight
up

Once

the
head
zs

Installed
do
not

rotate
the

camshaft
and

crankshaft

separately
as

damage
to
the

piston

tops
might
result

3
Place
the

cyhnder
gently
onto
the
head

gask
et

NOTE
Three

dIfferent

types
of
bolts

are
used

to
hold
down
the
head

Make

certain
the

proper
ones
are
used

In

the

proper
places

4
Insert
head
bolts

through
holes
ill
head
and

thread
them
mto
the

cyhnder
block

5

Refemng
to

Figure
62

use
a

torque
wrench

and
Datsun
tool
ST49010000
or

equivalent
to

tIghten
the
head
bolts
to

specIficatIon
Tighten

them

gradually
m
three
or
four

stages
wlnle
fol

lOWIng
the

sequence
diagram
Torque
values
are

hsted

m
the

specIfication
table

FUEL
SYSTEM
71

Dash
Pot

Adjustment

The

adjustment
of
the
dash

pot
IS
done

by

warmmg
up
the

engme
properly
and

checkIng
If

the
throttle
lever
touches
th
dash

pot
stem
as

the

engine
reaches
1
800
and
2
000

rpm
under

no
load
conditIons

Proper
contact
between
the

throttle
lever
and
the
dash

pot
stem

produces
a

normal
dash

pot
performance
Should
a
normal

mcrease
m

engme
speed
not
occur

adjust
the

dash

pot
as
follows

1
Loosen
the
dash

pot
locknuts

2
Rotate
the
dash

pot
nght
and
then
left

3

Adjust
the
dash

pot
so
that
the
throttle
lever

hIts
the
stem
between
1
800
and
2
000

rpm

4
Fasten
the
lock
nuts

securely

5
The
clearance
between
the
throttle
valve
and

the
throttle
chamber
wall
should
be
0
0709
m

0
8mm

or
10

degrees
In
throttle
valve

angle

MAJOR
CARBURETOR

SERVICE
PROCEDURES

A
carburetor
m

good
operatIng
condition
will

delIver
the

pr
per
gasolme
and
aIr
ratIos
for
all

engme
runnmg
speeds
A

gradual
declme
In

smoothness

response
and

power
Will
occur
as

the
carburetor

slIps
from

adjustment
and
Its
delI

cate

parts
become

dirty
and
worn
Overhaul

should

only
be

attempted
by
an

expenenced

mechanic

Accurate
calIbratIon
of

passages
and
dIS

charge
hole

reqUIre
that

extreme
care
be
taken

In

dISassembly
cleanmg
and

reassembly
Use

only
a

hIgh
grade
carburetor
cleaner
and
com

pressed
arr
to
clean

parts
and

passages
Never

use
wire
or
other

pOInted
Instruments
for
clean

ing
CalIbratIon
of
the
carburetor
will
be
af

fected
The

procedures
below
are

generally
true

for
all
models
As
an
aId

Figures
13
and
14
are

typIcal
examples
of
the
carburetors
used

Carburetor
Removal

1
Remove
the
au
cleaner

by
dIsconnectIng
all

hoses
attached
to
It

remoVmg
the
two
bolts

holdmg
the

aIr
cleaner
to
the

support
and

loos

enmg
the
band
bolt
at
the
base
of
the
aIr
cleaner

2
DIsconnect
fuellme
vacuum
Ime
and
choke

wire
u

eqUIpped
from
the
carburetor
3
Remove
the
throttle
lever

4
Remove
four
nuts
and
washers

holdmg
car

buretor
to
manIfold

5
Lift
carburetor
off
of
manuold

6
Remove
and
dIscard
carburetor
to
manuold

gasket

7
Place
carburetor
on
clean
workbench

Carburetor

Disassembly

1
The
maIn

Jets
slow

Jets
and
needle
valves
on

both
the

pnmary
and

secondary
systenIS
are

accessIble
from
outsIde
the
carburetor
Refer
to

FIgures
13
and
14
for
locatI
n

2
The
choke
chamber
can
be
detached

by
re

mOVIng
the

connectIng
rod

pump
connectIng

rod
return

sprmg
stop
pm
and
the

set
screws

I

that
hold

It
in

place

3
The

pnmary
and

secondary
emulSIon
tubes

can
be
disassembled

by
remOVIng
the
mam
air

bleeds

on
the

respectIve
SIdes

4

To
check
the
accelerator

pump
remove
the

cylInder
cover
Be
careful
not
to
lose
the

return

spnng
and
Inlet
valve
at
the
lower

part
of
the

pIston
durmg
dIsassembly

5
Detach
the
throttle
chamber
from
the
float

chamber

by
remOVIng
the
rod

lInkIng
the
dia

phragm
WIth
the

secondary
throttle
valve
and

the
four
screws
that
hold
It
However
It
IS

preferable
to
leave
the
throttle
valve
mtact
unless

absolutely
reqUired
If

It
IS

necessary
to
dlS

assemble
the
valve
It
should
be
Installed
so
that

the

secondary
throttle
valve
will
be

gap
free

OtherwIse
stable
Idle
and

good
slow

speed

performance
will
suffer

is
To
check
the
float
the
float
chamber
cover

must
be
removed

I

7
The

dIaphragm
IS
dIsassembled

by
removing

the
set
screws

holdmg
the

dIaphragm
chamber

cover
In

reassemblIng
the

diaphragm
be
careful

not
to
turn
the

edge
of
the

dIaphragm
up

8
In

dlsassemblmg
and

reassembling
the
mter

lockIng
lInks
take
care
so
that
each

lInkage
has

a
smooth
actIon
and
that

parts
are
not
forced

mto

pOSItIon

9
For
vehIcles

equipped
With
an
automatIc

choke
remove
the
brmetal

case

by
releasmg
the

set
screws
The
bimetal

1l
extremely
senSItIve