1967 CHEVROLET CAMARO check oil

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

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CAUTION!

QV NEVER
OIL

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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 6-6

CHOKE VALVE

COMPLETELY

CLOSED

PULL UPWARD ON

ROD TO END OF

TRAVEL

BEND ROD

TO ADJUST
ROD IN BOTTOM

OF SLOT

BOTTOM OF

ROD SHOULD

EVENWITH

TOP OF

HOLE
CHOKE VALVE

CLOSED

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF HOLE

TOP OF ROD

SHOULD BE EVEN

WITH BOTTOM

OF HOLE (CHOKE

CLOSED)

^..BEND ROD TO

ADJUST

_PULL DOWNWARD

ON ROD TO CON-

TACT STOP

L6 (TYPICAL)

V8 327-275 HP

V8 350-295 HP
BEND ROI

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
11 - Remote Choke Adjustment

sequence outlined on Torque Sequence Chart. A slight

leak at the intake manifold destroys engine performance

and economy.

Service Fuel Lines and Fuel Filter

1.
Inspect fuel lines for kinks, bends or leaks and cor-

rect any defects found, • • •

2.
Inspect filter and replace if plugged.

NOTE:
If a complaint of poor high speed per-

formance exists on the vehicle, fuel pump tests

described in Section 6M should be performed.

Service Cooling System

1.
Inspect cooling system for leaks, weak hoses, loose

hose clamps and correct coolant level, and service

as required.

NOTE:
A cooling system pressure test, as de-

scribed in "Additional Checks and Adjustments"

in this section, may be performed to detect

internal or external leaks within the cooling

system.

Check and Adjust Accelerator Linkage

1.
Disconnect accelerator rod at carburetor throttle

lever.

2.
Hold carburetor throttle lever in wide position.

3.
Pull accelerator rod to wide open position. (On ve-

hicles equipped with automatic transmission, pull

through detent).

4.
Adjust accelerator rod to freely enter hole in carbu-

retor throttle lever.'

NOTE:
Accelerator linkage is outlined in de-

tail in Section 6M.
5. Connect accelerator rod at throttle lever.

Service Crankcase Ventilation (Fig. 10}

All engines have either "Positive" or "Closed Positive"

ventilation systems utilizing manifold vacuum to draw

fumes and contaminating vapors into the combustion

chamber where they are burned. Since it affects every

part of the engine, crankcase ventilation is an important

function and should be understood and serviced properly.

In both "Positive" and "Closed Positive" ventilation,

air is drawn through the engine, (through a regulating

valve) into the manifold, drawing' crankcase vapors and

fumes with it to be burned. "Positive" ventilation uses a

vented-meshed cap for clean air intake to the engine,

while . "Closed Positive" ventilation system draws the

clean air from the carburetor air cleaner and has a

nonvented oil filler cap.

1.
Ventilation valve may be checked as outlined under

"Additional Checks and Adjustments".

2.
Inspect for deteriorated or plugged hoses.

3.
Inspect all hose connections.

4.
On closed positive ventilation systems, remove flame

arrestor and wash in solvent then dry with com-

pressed air.

Service Air Injection Reactor System

Inspect air injection reactor system for evidence of

leaks,
deteriorated hoses, cracked air manifolds or tubes

and loose hose clamps. Inspect air injection pump belt

condition and tension. Make all necessary repairs as

outlined in "Section 6T".

Because of the relationship between "Engine Tune Up"

and "Unburned Exhaust Gases", the condition of Engine

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 6-11

Fig.
18 - Cooling System Pressure Test

Carburetor

Refer to Section 6M to perform adjustments such as

idle vent, float level, pump rod and secondary valve.

Fuel Pump

If the owner has complained of poor high speed per-

formance, the fuel pump may be at fault. Too low a

pump pressure or volume will cause a high speed "miss"

because of lack of fuel delievered to the carburetor,

while too high a pressure will cause carburetor flooding.

Check fuel pump as outlined in Section 6M.

Cooling System

The following test may be performed with pressure

testing equipment available commercially for this pur-

pose.
This test provides an excellent means of detecting

internal or external leaks within the cooling system.

1.
Remove radiator cap.

2.
Apply a test pressure of 3 pounds higher than the ra-

diator cap (fig. 18). i.e. 18 pounds for a 15 pound

cap.

3.
If the pressure will not hold, there is either an

internal or external leak in the system.

Cylinder Head Torque and Valve Adjustment

Retorquing the cylinder head bolts is not necessary

unless a gasket has been replaced, or a leak is suspected.

Valve lash must always be adjusted after the head has

been torqued.

Before adjusting the valve lash, it is extremely impor-

tant that the engine be thoroughly warmed up to normal-

ize the expansion of all parts. This is very important

because during the warm-up period, the valve clearances

will change considerably.

Hydraulic

1.
After the engine has been normalized, remove rocker

arm covers and gaskets.

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.

2.
With the engine running at idle, back off valve rocker

arm nut until the valve rocker arm starts to clatter.

3.
Turn rocker arm nut down slowly until the clatter

just stops. This is the zero lash position.

4.
Turn nut down 1/4 additional turn and pause 10 sec-

onds until engine runs smoothly* Repeat additional

1/4 turns, pausing 10 seconds each time, until nut

has been turned down 1 full turn from the zero lash

position.

NOTE: This 1 turn preload adjustment must be

done slowly to allow the lifter to adjust itself to

prevent the possibility of interference, between

the inlet valve head and top of piston, which

might result in internal damage and/or bent push

rods.
Noisy lifters should be replaced.

5.
Repeat Steps 2, 3 and 4 to adjust the rest of the

valves.

6. Clean gasket surfaces on cylinder heads and rocker

arm covers with degreaser then install rocker arm

covers, using new gaskets, and torque bolts to

specifications.

Mechanical

1.
Normalize the engine.

2.
Remove rocker arm covers and gaskets.

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.

3.
Use a socket wrench on self-locking rocker arm stud

nut and adjust as needed to obtain valve lash (see

tune up chart) measured between rocker arm and

valve stem with a leaf type feeler gauge.

4.
Stop engine, clean gasket surfaces on cylinder heads

and rocker arm covers with degreaser then install

rocker arm covers, using new gaskets, and torque

bolts to specifications.

Fig.
19
- Oil Deflector Clips Installed

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 6-15

2.
Install rocker arms, rocker arm balls and rocker

arm
nuts.
\
Tighten rocker arm nuts until all lash is

eliminated. .

3.
Adjust valves when lifter is on base circle of cam-

shaft lobe as follows:

a. Mark distributor housing, with chalk, at each cyl-

inder position (plug wire) then disconnect plug

wires at spark plugs and coil and remove distri-

butor cap and plug wire assembly (if not previ-

ously done).

b.
Crank engine until distributor rotor points to

number one cylinder position and breaker points

are open. Both valves on number one cylinder

may now be adjusted.

c. Back out adjusting nut until lash is felt at the push

rod then turn in adjusting nut until all lash is re-

moved. This can be determined by checking push

rod side play while turning adjusting nut (fig. 2L).

When play has been removed, turn adjusting nut

in one full additional turn (to center lifter

plunger).

d. Adjust the remaining valves, one cylinder at a

time,
in the same manner.

4.
Install distributor cap and spark plug wire assembly.

5.
Install rocker arm cover as outlined.

6. Adjust carburetor idle speed and mixture.

VALVE LIFTERS

Hydraulic valve lifters very seldom require attention.

The lifters are extremely simple in design readjustments

are not necessary, and servicing of the lifters requires

only that care and cleanliness be exercised in the han-

dling of parts.

Locating Noisy Lifters

Locate a noisy valve lifter by using a piece of garden

Fig.
2L - Valve Adjustment
hose approximately four feet in length. Place one end of

the hose near the end of each intake and exhaust valve

with the other end of the hose to the ear. In this manner,

the sound is localized making it easy to determine which

lifter is at fault.

Another method is to place a finger on the face of the

valve spring retainer. If the lifter is not functioning

properly, a distinct shock will be felt when the valve

returns to its seat.

The general types of valve lifter noise are as follows:

1.
Hard Rapping Noise--Usually caused by the plunger

becoming tight in the bore of the lifter body to such

an extent that the return spring can no longer push

the plunger back up to working position. Probable

causes are:

a. Excessive varnish or carbon deposit causing

abnormal stickiness.

b.
Galling or "pickup" between plunger and bore of

lifter body, usually caused by an abrasive piece

of dirt or metal wedging between plunger and

lifter body.

2.
Moderate Rapping Noise--Probable causes are:

a. Excessively high leakdown rate.

b.
Leaky check valve seat.

c. Improper adjustment.

3.
General Noise Throughout the Valve Train—This

will, in almost all cases, be a definite indication of

insufficient oil supply, or improper adjustment.

4.
Intermittent Clicking—Probable causes are:

a. A microscopic piece of dirt momentarily caught

between ball seat and check valve ball.

b.
In rare cases, the ball itself may be
out-of-

round or have a flat spot.

c. Improper adjustment.

In most cases where noise exists in one or more lifters

all lifter units should be removed, disasssmbled, cleaned

in a solvent, reassembled, and reinstalled in the engine.

If dirt, varnish, carbon, etc. is shown to exist in one unit,

it more than likely exists in all the units, thus it would

only be, a matter of time before all lifters caused trouble.

Removal

1.
Remove valve mechanism as outlined.

2.
Mark distributor housing, with chlak, at each cylin-

der position (plug wire) then disconnect plug wires at

spark plugs and coil and remove distributor cap and

plug wire assembly.

3.
Crank engine until distributor rotor points to number

one position, then disconnect distributor primary lead

at coil and remove distributor.

4.
Remove push rod covers (discard gaskets).

5.
Remove valve lifters.

NOTE: Place valve lifters in a rack so they

may be reinstalled in the same location.

Installation

1.
Install valve lifters.

NOTE:
Whenever new valve lifters are being

installed, coat foot of valve lifters with Molykote

or its equivalent.

2.
Install push rod covers, using new gaskets, and

torque bolts to specifications.

3.
Install distributor, positioning rotor to number one

cylinder position, then connect primary lead at coil.

4.
Install and adjust valve mechanism as outlined.

CHEVROLET CHASSIS SERVICE MANUAL