1967 CHEVROLET CAMARO battery

SECTION 6

ENGINE

CONTENTS
OF
THIS SECTION

Page

Engine Tune Up
6-1
Torque Sequence

Engine Mechanical
(In
Line)
6-12
Special Tools
. .

Engine Mechanical (V8)
6-24
Page

6-39

6-40

ENGINE TUNE UP

INDEX

Page

General Description
. 6-1

Mechanical Checks and Adjustments
6-1

Spark Plug Removal
6-1

Test Compression
6-1

Service and Install Spark Plugs
6-2

Service Ignition System
6-3

Service Battery
and
Battery Cables
6-5

Service Delcotron
and
Regulator
6-5

Service
Fan
Belt
6-5

Service Manifold Heat Valve
6-5

Tighten Manifold
6-5

Service Fuel Lines
and
Fuel Filter ..........
6-6

Service Cooling System
6-6

Check and Adjust Accelerator Linkage
6-6

Service Crankcase Ventilation
6-6

Service
Air
Injection Reactor System
6-6

Choke Adjustment
6-7
Page

Instrument Cheek-Out
6-7

Instrument Hook-Up.
. 6*7

Check and Adjust Dwell
6-7

Check Dwell Variation
6-7

Check and Adjust Timing
6-8

Adjust Idle Speed
and
Mixture
6-8

Additional Checks and Adjustments
. 6-8

Testing Crankcase Ventilation Valve
. 6-8

Testing Cranking Voltage
6-8

Cylinder Balance Test
. 6-8

Battery
6-8

Ignition
; 6-8

Carburetor
6-11

Fuel Pump
6-11

Cooling System
. 6-11

Cylinder Head Torque and Valve Adjustment
..... 6-11

GENERAL DESCRIPTION

The engine tune up
is
important
to the
modern automo-

tive engine with
its
vastly improved power and perform-

ance.
The
higher compression ratios, improved electri-

cal systems
and
other advances
in
design, make today1 s

engines more sensitive
and
have
a
decided effect
on

power, performance and fuel consumption.

It
is
seldom advisable
to
attempt
a
tune up
by
correc-

tion
of one or two
items only. Time will normally
be

saved
and
more lasting results assured
if the
technician

will follow
a
definite
and
thorough procedure
of
analysis

and correction
of all
items affecting power, performance

and economy.

The tune
up
will
be
performed
in
two parts.
The
first

part will consist
of
visual and mechanical checks and
ad-

justments;
the
second part will consist
of
an instrument

checkout that
can be
performed with
any one of the
units
of service equipment available
for
this purpose. Always

follow
the
instructions provided
by the
manufacturer
of

the particular equipment
to be
used.

Additional checks
and
adjustments
are
included
in the

latter part
of
this section
for use as
required. Many
of

these operations
can be
used
to
isolate and correct trou-

ble located during
the
tune up. Where conditions
are
UB-

covered requiring major corrective action, refer
to the

appropriate section
of
this manual
or the
Passenger

Chassis Overhaul Manual
for
detailed service informa-

tion.

Typical illustrations
and
procedures
are
used except

where specific illustrations
or
procedures
are
necessary

to clarify
the
operation. Illustrations showing bench
op-

erations
are
used
for
clarification however
all
operations

can
be
performed
on the
vehicle.

MECHANICAL CHECKS
AND
ADJUSTMENTS

Spark Plug Removal

Remove any foreign matter from around spark plugs
by

blowing
out
with compressed
air,
then disconnect wires

and remove plugs.

Test Compression
(Fig. 1)

The compression check
is
important because
an
engine

with
low or
uneven compression cannot
be
tuned success-
fully.
It is
essential that improper compression
be cor-

rected before proceeding with
the
engine tune
up.

1.
Remove
air
cleaner
and
block throttle
and
choke
in

wide open position.

2.
Hook
up
starter remote control cable
and
insert

compression gauge firmly
in
spark plug port.

CAUTION: Whenever
the
engine
is
cranked

CHEVROLET
C*
IS SERVICE MANUAL

ENGINE
6-3

(ROUND) Y~~fll^H

CENTRIFUGAL
A ^k

ADVANCE--jflgKpl

MECHANISM
UB|

CAM
KSK^2

LUBRICATOR
VlSMi

REPLACEMENT
^BK

-^ADJUST
SQUARELY

AND
JUST

TOUCHING
LOBE

OF
CAM
/ROTOR

HBB
__

I^BH^F
?
(SOUARE)

^K^ I /—
CAM

jKft^J / LUBRICATOR

H^T^
CAUTION!

QV NEVER
OIL

•L-^
CAM LUBRICATOR-

REPLACE
WICK

WHEN
NECESSARY
LATERAL

MISALIGNMENT
PROPER

LATERAL ALIGNMENT

Fig.
4- Distributor (V8)

CAUTION: Use extreme care
-when
using tap to

prevent cross threading. Also crank engine sev-

eral times to blow out any material dislodged

during cleaning operation.

7. Install spark plugs with new gaskets and torque to

specifications.

NOTE:
The following are some of the

greatest causes of unsatisfactory spark plug

performance.

•
Installation of plugs with insufficient torque to

fully seat the gasket.

•
Installation of the plugs using excessive torque

which changes gap settings.

•
Installation of plugs on dirty gasket seal.

•
Installation of plugs into corroded spark plug hole

threads.

8^ Connect spark plug wiring.

Service
Ignition System

1.
Remove distributor cap, clean cap and inspect for

cracks, carbon tracks and burned or corroded ter-

minals. Replace cap where necessary.

2.
Clean rotor and inspect for damage or deterioration.

Replace rotor where necessary.

3.
Replace brittle, oil soaked or damaged spark plug

wires.
Install all wires to proper spark plug. Proper

positioning of spark plug wires in supports is impor-

tant to prevent cross-firing.

4.
Tighten all ignition system connections.

5. Replace or repair any wires that are frayed, loose or

damaged.
Us
CORRECT
LATERAL MISALIGNMENT BY

j BENDING
FIXED CONTACT SUPPORT

[NEVER
BEND BREAKER LEVER

Fig.
5 - Point Alignment

Magnetic
Pulse(Breakerless)
Distributor

There are no moving parts in the ignition pulse ampli-

fier, and the distributor shaft and bushings have perma-

nent type lubrication, therefore no periodic maintenance

is required for the magnetic pulse ignition system. Refer

to Section 6Y for an analysis of problems and/or repair

procedures encountered on the Transistorized (Magnetic

Pulse) ignition system.

Standard
(Breaker Point) Distributor
(Figs.
3 or 4)

1.
Check the distributor centrifugal advance mechanism

by turning the distributor rotor in a clockwise direc-

tion as far as possible, then releasing the rotor to

see if the springs return it to its retarded position.

If the rotor does not return readily, the distributor

must be disassembled and the cause of the trouble

corrected.

2.
Check to see that the vacuum spark control operates

freely by turning the movable breaker plate counter-

clockwise to see if the spring returns to its retarded

position. Any stiffness in the operation of the spark

control will affect the ignition timing. Correct any

interference or binding condition noted.

3.
Examine distributor points and clean or replace if

riecessary.

DO
NOT SUCK

IN
TOO MUCH

ELECTROLYTE

TAKE
READING

AT
EYE LEVEL

Fig.
6 - Testing Specific Gravity of Battery

CHEVROtET
CHASSIS SERVICE MANUAL

ENGINE
6-5

Service Battery and Battery Cables

1.
Measure the specific gravity of the electrolyte in

each cell (fig. 6). If it is below 1.230 (corrected to

80°F.) recharge with a slow rate charger, or if de-

sired, further check battery.

2.
Connect a voltmeter across the battery terminals and

measure the terminal voltage of the battery during

cranking (disconnect the coil primary lead at the

negative terminal during this check to prevent engine

from firing). If the terminal voltage is less than 9.0

volts at room temperature, approximately 80°

±
20°
F.,
the battery should be further checked. See

Section 6Y for further tests.

3.
Inspect for signs of corrosion on battery, cables and

surrounding area, loose or broken carriers, cracked

or bulged cases,- dirt and acid, electrolyte leakage

and low electrolyte level. !Fill cells to proper level

with distilled water or water passed through a

"demineralizer".

The top of the battery should be clean and the bat-

tery hold-down bolts properly tightened. Particular

care should be taken to see that the top of the battery

is kept clean of acid film and dirt. When cleaning

batteries, wash first with a dilute ammonia or soda

solution to neutralize any acid present and then flush

off with clean water. Keep vent plugs tight so that

the neutralizing solution does not enter the cell. The

hold-down bolts should be kept tight enough to prevent

the battery from shaking around in its holder, but

they should not be tightened to the point where the

battery case will be placed under a severe strain.

To insure good contact, the battery cables should

be tight on the battery posts. Oil battery terminal

felt washer. If the battery posts or cable terminals
are corroded, the cables should be cleaned separately

with a soda solution and wire brush. After cleaning

and before installing clamps, apply a thin coating of

petrolatum to the posts and cable clamps to help

retard corrosion.

If the battery has remained undercharged, check

for loose or defective fan belt, defective Delcotron,

high resistance in the charging circuit, oxidized

regulator contact points, or a low voltage setting.

If the battery has been using too much water, the

voltage output
is-
too high.

Service Deicotron and Regulator

The Delcotron and regulator tests during tune up con-

sist of the above battery tests; the condition of the battery

indicating further tests and adjustments as outlined in

Section 6Y.

Service Belts (Fig. 7)

Inspect belt condition.

Check and adjust if necessary for correct tension of

belt, as follows:

• Using a strand tension gauge, check the belt tension.

• Adjust belt until the specified tension is reached.

(See Tune Up Chart.)

Service Manifold Heat Valve (Figs. 8 or 9)

Check manifold heat control valve for freedom of oper-

ation. If shaft is sticking, free it up with GM Manifold

Heat Control Solvent or its equivalent.

NOTE: Tap shaft end to end to help free it up.

Tighten Manifold

Tighten intake manifold bolts to specifications in the

FLAME

ARRESTOR
FLAME

ARRESTOR

NON-VENTED\

CAP
V\ VALVE

CLOSED
POSITIVE (283 & 327)

POSITIVE
(IN LINE)

POSITIVE
(327)

POSITIVE
(396 & 427)

Fig.
10 -
Crank case
Ventilation Systems

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-8

Check
and
Adjust Ignition Timing
(Fig. 13)

1.
Disconnect
the
distributor spark advance hose
and

plug
the
vacuum source opening.

2.
Start engine
and run at
idle speed
(see
tune
up
chart).

3.
Aim
timing light
at
timing
tab.

NOTE:
- The
markings
on the
tabs
are in 2°

increments
(the
greatest number
of
markings
on

the
"A"
side
of the "O"). the "O"
markings
is

TDC
of
#1 cylinder
and all
BTDC settings fall
on

the
"A"
(advance) side
of "O".

4.
Adjust
the
timing
by
loosening
the
distributor clamp

and
,
rotating
the
distributor body
as
required, then

tighten
the
clamp.

5.
Stop engine
and
remove timing light
and
reconnect

the spark advance hose.

Adjust Idle Speed
and
Mixture
(Fig. 14)
(Except when

equipped with
Air
Injection Reactor System)

1.
As a
preliminary adjustment, turn idle mixture

screws lightly
to
seat
and
back
out 2
turns.

CAUTION:
Do not
turn idle mixture screw

tightly against seat
or
damage
may
result.

2.
With engine running
at
operating temperature (choke

wide open) adjust idle speed screw
to
bring idle

speed
to
specified
rpm
(automatic transmission
in
drive, manual transmission
in
neutral).

3.
Adjust idle mixture screw
to
obtain highest steady

idle speed
(1/4
turn
out
from lean roll).

4.
Repeat Steps
2 and 3 as
needed
for
final adjustment.

5.
Shut down
the
engine, remove gauges
and
install
air

cleaner.

Adjust Idle Speed
and
Mixture
(Fig. 14)
(With
Air

Injection Reactor System)

The recommended adjustment procedure
for Air
Injec-

tion Reactor System equipped engines
is as
follows:

1.
As a
preliminary adjustment, turn idle mixture

screws lightly
to
seat
and
than back
out 3
turns.

CAUTION:
Do not
turn idle mixture screw

tightly against seat
or
damage
may
result.

2.
With engine running
at
operating temperature, choke

wide open,
and
parking brake applied, adjust idle

specified idle speed (automatic

"drive"-manual transmission
in
to

in
screw

transmission

"neutral").

;3.
Adjust idle mixture screw (turn
in) to
"lean roll"

position; then turn screw
out 1/4
turn
(1/4
turn rich

from "lean roll").
The
definition
of
"lean roll" point

is
a 20 to 30 rpm
drop
in
engine speed, obtained
by

leaning
the
idle mixture.

4.
Repeat Steps
2 and 3 as
needed
for
final adjustments.

ADDITIONAL CHECKS
AND
ADJUSTMENTS

Testing Crankcase Ventilation Valve
(Fig. 15) 0

1.
Connect tachometer
and
vacuum gauge
as for
idle

speed
and
mixture adjustment.

2.
Set
parking brake, start engine
and
adjust idle speed

and mixture.

3.
Disconnect ventilation hose
at
valve, block opening
of

valve
and
read engine
rpm
change.

4.
A
change
of
less than
50 rpm
indicates
a
plugged

ventilation valve
-
replace
the
valve.

Cylinder Balance Test
(Fig. 16)

It
is
often difficult
to
locate
a
weak cylinder.
A com-

pression test,
for
example, will
not
locate
a
leaky intake

manifold,
a
valve
not
opening properly
due to a
worn

camshaft,
or a
defective spark plug.

With
the
cylinder balance test,
the
power output
of one

cylinder
may be
checked against another, using
a set of

grounding leads. When
the
power output
of
each cylinder

is
not
equal,
the
engine will lose power
and run
roughly.

Perform
a
cylinder balance test
as
follows:

1.
Connect
the
tachometer
and
vacuum gauge.

2.
Start engine
and run at 1500 rpm.

3.
Ground large clip
of
grounding leads
and
connect
in-

dividual leads
to all
spark plugs except
the
pair being

tested.

Divide
the
firing order
in
half
and
arrange
one
half

over
the
other.
The
cylinders
to be
tested together
ap-

pear
one
over
the
other.

L4 Firing Order
V8 Firing Order

1-8-4-3-6-5-7-2

1-6, 8-5, 4-7, 3-2

1-3-4-2
= 1-3

4-2

L6 Firing Order

1-5-3-6-2-4
=
=
1-4. 3-2

1-5-3

6-2-4
1-6, 5-2, 3-4
1-8-4-3

6-5-7-2

4.
Operate engine
on
each pair
of
cylinders
in
turn
and

note engine
rpm and
manifold vacuum
for
each pair.

A variation
of
more than
1
inch
of
vacuum
or 40 rpm

between pairs
of
cylinders being tested indicates that

the cylinders
are off
balance.

Battery

The battery should
be
checked with special testing

equipment
and to the
equipment manufacturers specifica-

tions.
See
Section 6Y
for
complete information
on
battery

tests.

Ignition

The following additional ignition checks
may be
made

with
any of
several pieces
of
equipment available
for un-

covering
the
source
of
engine difficulties.
The
specific

operating instructions
of the
equipment manufacturer

should
be
followed:

Cranking voltage

Ignition switch

Distributor resistance

Secondary resistance

Ignition output
and
secondary leakage

Cranking Voltage
(Fig. 17)

1.
Disconnect coil primary lead
at the
coil negative

terminal
to
prevent engine from firing during

cranking.

2.
Connect voltmeter between primary terminal
of coi|

(resistance wire side)
and
ground.

3.
Operate starting motor.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-10

Fig.
15 - Crank case Ventilation Valve

a. If voltage is 9 volts or more and cranking speed

is satisfactory, the battery, starter, cables,

starter switch and ignition circuit to coil (by-

passing resistance wire) are in good condition.

b.
If below 9 volts, check circuit until difficulty is

located.

Meter reading below specification—Weak bat-

tery; defective cables, connections, switch or

starter; defective ignition circuit to coil.

Cranking speed below normal--Excessive re-

sistance in cables or starting motor; excessive

mechanical drag in engine.

Uneven cranking speed—Uneven compression,

defective starter or starter drive.

Ignition Switch

With voltmeter connected as described for the Cranking

Voltage Test, turn ignition switch to ON. Voltage should

drop to 5 to 7 volts as current is now passing through

high resistance wire connected between ignition switch

and (+) positive terminal of coil. If battery voltage of

12 volts is obtained, the starter solenoid is by-passing

the high resistance wire connected between ignition

switch and (+) positive terminal of coil, thus the starter

solenoid is not functioning properly to bypass the ignition

resistance wire or the ignition circuit is incorrectly

wired.

Distributor Resistance

Use equipment as directed by manufacturer.

Excessive
(t n ti ft

Fig.
16 - Cylinder Balance Test
Fig.
17 - Testing Cranking Voltage

resistance in primary circuit must be eliminated before

continuing with test procedure.

Secondary Resistance

Use equipment as dire6ted by manufacturer.

• Uniform "normal readings" as specified by manu-

facturer indicate all secondary circuit components

are in good condition.

• If all readings are "below normal," check for cor-

roded coil tower terminal, poorly connected or

broken coil wire, center cap electrode or rotor tip

burned, or an open secondary in coil.

• If readings are "higher than normal" at two or more

plugs adjacent in firing order, cross firing is oc-

curring in distributor cap or between spark plug ca-

bles concerned.

• If meter reads off scale to left, the coil polarity is

reversed. Check for reversed coil primary wires,

wrong coil or reversed vehicle battery connections.

Ignition Output and Secondary Leakage

Use equipment as directed by manufacturer.

• GOOD readings indicate both ignition output and

secondary insulation are good.

• If all readings are BAD or if ignition test calibrator

cannot be adjusted to Set Line, check for high re-

sistance in primary circuit, defective distributor

points, coil or condenser.

e If readings are BAD when certain plug wires are

lifted off, check for cracks or carbon tracks in dis-

tributor cap or defective insulation on those plug

wires being lifted off.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-12

ENGINE
MECHANICAL

IN LINE

INDEX

Page

General Description . „ 6-12

Component Replacement and Adjustment 6-12

.Engine Assembly 6-12

Removal 6-12

Installation 6-13

Manifold Assembly 6-14

Removal . 6-14

Installation 6-14

Rocker Arm Cover . 6-14

Removal 6-14

mstallation . . . 6-14

Valve Mechanism
......
1 6-14

Removal 6-14

Installation and Adjustment . 6-14

Valve Lifters
..............
6-15

Locating Noisy Lifters
„.;....
6-15

Removal
.'.*...•
6-15

Installation . 6-15

Valve Stem Oil Seal and/or Valve Spring . 6-16

Replacement . 6-16

Cylinder Head Assembly . 6-16

Removal 6-16

Installation . 6-16

Oil Pan . » 6-17

Removal . . . ; . . 6-17

Installation
.........
. 6-17

Oil Pump . 6-18
Page

Removal . 6-18

Installation . 6-18

Oil Seal (Rear Main) . 6-19

Replacement 6-19

Crankshaft Pulley and Hub 6-19

Removal 6-19

Installation 6-19

Torsional Damper 6-19

Removal 6-19

Installation 6-19

Crankcase Front Cover . 6-20

Removal . 6-20

Installation 6-20

•
Oil Seal (Front Cover) 6-20

Replacement 6-20

Camshaft 6-21

Measuring Lobe Lift . ... .
.-.••.-.
6-21

Removal 6-21

Installation 6-22

Timing Gears
..••••.............••• 6—22

Replacement
6-22

Flywheel
6-22

Removal
* 6-22

Installation
6-22

Engine
Mounts
6-23

Replacement
(Front)
6-23

Replacement
(Rear)
. 6-23

GENERAL DESCRIPTION

The
In
Line engines
(fig. 1L)
covered
in
this section

are
the 1H3 cu. in. L4, the 194,
230
and
250
cu. in. L6,

regardless
of
which passenger vehicle they
are
used
in.

This section covers
the
removal
and
installation
of en-

gine assemblies;
the
removal, installation
and
adjustment

of some sub-assemblies
and
replacement
of
some
com-

ponents.
For
service
to all
components
and
sub-assem-

blies (after removal)
and
removal
of
some sub-assem-

blies,
refer
to
Section
6 of the
Chassis Overhaul Manual.
Because
of the
interchangeability
and
similarity
of

many engine sub-assemblies
and
engine parts, regardless

of which passenger vehicle they
are
used
in,
typical illus-

trations
and
procedures
are
used except where specific

illustrations
or
procedures
are
necessary
to
clarify
the

operation. Although illustrations showing bench opera-

tions
are
used, most single operations, when
not
part
of a

general overhaul, should
be
performed
(if
practical) with

the engine
in the
vehicle.

COMPONENT REPLACEMENT
AND
ADJUSTMENT

ENGINE ASSEMBLY

Removal

1.
Drain cooling system
and
engine
oil.

2.
Remove
air
cleaner
and
disconnect battery cables
at 7.

battery.

3.
Remove hood
as
outlined
in
Section 11.

4.
Remove radiator
and
radiator shroud
as
outlined
in

Section 13.

5.
Remove
fan
blade
and
pulley
as
outlined
in
Section

6K.

6. Disconnect wires
at:

• Starter Solenoid
8.

• Delcotron
9.
Temperature Switch

Oil Pressure Switch

Coil

Disconnect:

Accelerator linkage
at
manifold bellerank.

Exhaust pipe
at
manifold flange.
.

Fuel line (from tank)
at
fuel pump.

Vacuum line
to
power brake unit
at
manifold
(if

so equipped).

• Power steering pump lines
at
pump
end (if so

equipped).

Raise vehicle
and
place
on
jack stands.

Remove propeller shaft.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-14

b.
Bolt transmission to engine, then raise engine and

transmission assembly and install flywheel to

converter attaching bolts.

c. Install converter
housing*
underpan and starter.

3.
Tilt and lower engine and transmission assembly into

the chassis as a unit, guiding engine to align front

mounts with frame supports.

4.
Install front mount through bolts and torque to

specifications.

5.
Raise engine enough to install rear crossmember,

then install crossmember, install rear mount, lower

engine and torque bolts to specifications.

6. Remove lifting device and lifting adapter then install

rocker arm cover as outlined.

7.
On synchromesh equipped vehicles, install clutch

cross shaft engine bracket, then adjust and connect

clutch as outlined in Section 7.

8. Connect:

• Speedometer cable.

• Shift linkage at transmission.

9; Install propeller shaft.

10.
Remove jack stands and lower vehicle.

11.
Connect:

Power steering pump lines (if disconnected).

Vacuum line to power brake unit (if disconnected).

Fuel line at fuel pump.

Exhaust pipe at manifold flange.

Accelerator linkage at manifold bellcrank.

12.
Connect wires at:

Coil

Oil pressure switch

Temperature switch

Delcotron

Starter solenoid

13.
Install pulley, fan blade and fan belt as outlined in

Section 6K.

14.
Install radiator and shroud as outlined in Section 13.

15.
Install and adjust hood as outlined in Section 11.

16.
Connect battery cables.

17.
Fill with coolant, engine oil and transmission oil,

then start engine and check for leaks.

18.
Perform necessary adjustments and install air

cleaner.

MANIFOLD ASSEMBLY

Removal

1.
Remove air cleaner.

2.
Disconnect both throttle rods at bellcrank and re-

move throttle return spring.

3.
Disconnect fuel and vacuum lines at carburetor.

Disconnect choke cable on \A engines.

4.
Disconnect crankcase ventilation hose at rocker arm

cover.

5.
Disconnect exhaust pipe at manifold flange and dis-

card packing.

6. Remove manifold attaching bolts and clamps then

remove manifold assembly and discard gaskets.

7.
Check for cracks in manifold castings.

8. If necessary to replace either intake or exhaust

manifolds, separate them by removing one bolt and

two nuts at center of assembly. Reassemble mani-

folds using a new gasket. Tighten finger tight and

torque to specifications after assembly to cylinder

head. Transfer all necessary parts.
Installation

1.
Clean gasket surfaces on cylinder head and

manifolds*

2.
Position new gasket over manifold end studs on head

and carefully install the manifold in position making

sure the gaskets are in place.

3.
Install bolts and clamps while holding manifold in

place with hand.

4.
Torque bolts to specifications.

NOTE: On L6 engines center bolt and end bolt

torque differ.

5.
Connect exhaust pipe to manifold using a new

packing.

6. Connect crankcase ventilation hose at rocker arm

cover.

7.
Connect fuel and vacuum lines at carburetor.

8. On L4 engines connect choke cable and adjust as out-

lines in Section 6M.

9. Connect throttle rods at bellcrank and install throttle

return spring.

10.
Install air cleaner, start engine, check for leaks and

adjust carburetor idle speed and mixture.

ROCKER ARM COVER

Removal

1.
Disconnect crankcase ventilation hose(s) at rocker

arm cover.

2.
Remove air cleaner.

3.
Disconnect temperature wire from rocker arm cover

clips.

4.
Remove rocker arm cover. '

CAUTION: Do Not pry rocker arm cover loose

Gaskets adhering to cylinder head and rocker

arm cover may be sheared by bumping end of

rocker arm cover rearward with palm of hand or

a rubber mallet.

Installation

1.
Clean gasket surfaces on cylinder head and rocker

arm cover with degreaser then, using anew gasket,

install rocker arm cover and torque bolts to

specifications.

2.
Connect temperature wire at rocker arm cover clips.

3.
Install air cleaner.

4.
Connect crankcase ventilation hoses.

VALVE MECHANISM

Removal

1.
Remove rocker arm cover as outlined.

2.
Remove rocker arm nuts, rocker arm
balls,
rocker

arms and push rods.

NOTE:
Place rocker arms, rocker arm balls

and push rods in a rack so they may be rein-

stalled in the same location.

Installation and Adjustment

NOTE:
Whenever new rocker arms and/or

rocker arm balls are being installed, coat bear-

ing surfaces of rocker arms and rocker arm

balls with Molykote or its equivalent.

1.
Install push rods,

socket.
Be sure push rods seat in lifter

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-16

5.
Adjust ignition timing and carburetor idle speed and

mixture.

VALVE STEM OIL SEAL AND/OR VALVE SPRING

Replacement

1.
Remove rocker arm cover as outlined.

2.
Remove spark plug, rocker arm and push rod on the

cylinder(s) to be serviced.

3.
Apply compressed air to the spark plug hole to hold

the valves in place.

NOTE: A tool to apply air to the cylinder is

available through local jobbers or may be manu-

factured. In manufacturing this Tool a AC-46N

Spark Plug or its equivalent is recommended.

This will make the Tool universal for all

Chevrolet engines. Chisel the spark plug as

shown, then drive the porcelain out of the plug

by tapping the center electrode against a hard

block. Using a 3/8" pipe tap, cut threads in the

remaining portion of the spark ^>lug and assem-

ble as shown (fig. 3L).

4.
Using Tool J-5892 to compress the valve spring, re-

move the valve locks, valve cap, valve shield and

valve spring and damper (fig. 4L).

5.
Remove the valve stem oil seal.

6. To replace, set the valve spring and damper, valve

shield and valve cap in place. The close coiled end

of the spring is installed against the cylinder head.

Compress the spring with
Too^
J-5892 and install oil

seal in the lower groove of the stem, making sure the

seal'is flat and not twisted.

NOTE: A light coat of oil on the seal will help

prevent twisting.

7.
Install the valve locks and release the compressor

tool, making sure the locks seat properly in the

upper groove of the valve stem.

NOTE: Grease may be used to hold the locks

in place while releasing the compressor tool.

8. Install spark plug, using a new gasket, and torque to

specifications.

9. Install and adjust valve mechanism as outlined.

CYLINDER HEAD ASSEMBLY

Removal

1.
Remove manifold assembly as. outlined.

2.
Remove valve mechanism as outlined.

3.
Drain cooling system (block).

4.
Remove fuel and vacuum line from retaining clip at

water outlet then disconnect wires from temperature

sending units.

5.
Disconnect upper radiator hose at water outlet hous-

ing and battery ground strap at cylinder head.

6. Remove coil (L6 engines only).

7.
Remove cylinder head bolts, cylinder head and gas-

ket. Place cylinder head on two blocks of wood to

prevent damage.

Installation

CAUTION: The gasket surfaces on both the

head and the block must be clean of any foreign
matter and free of nicks or heavy scratches.

Cylinder bolt threads in the block and threads

on the cylinder head bolt must be cleaned. (Dirt

will affect bolt torque.) Do not use gasket sealer

on composition steel asbestos gasket.

Fig. 3L -
AIF
Adapter Tool

1.
Place the gasket in position over the dowel pins with

the bead up.

2.
Carefully guide cylinder head into place over dowel

pins and gasket.

3.
Coat threads of cylinder head bolts with sealing com-

pound and install finger tight.

4.
Tighten cylinder head bolts a little at a time in the

sequence shown on the torque sequence chart until

the specified torque is reached.

5.
Install coil (if removed).

6. Connect upper radiator hose and engine ground strap.

7.
Connect temperature sending unit wires and install

fuel and vacuum lines in clip at water outlet.

8. Fill cooling system.
•

9. Install manifold assembly as outlined.

10.
Install and adjust valve mechanism as outlined.

Fig.
4L
- Compressing Valve Spring

CHEVROLET CHASSIS SERVICE MANUAL