light CHEVROLET CAMARO 1967 1.G Chassis Repair Manual

ENGINE 6-7

Tune Up should be checked whenever the Air Injection

Reactor System seems to be malfunctioning. Particular

care should be taken in checking items that affect fuel-air

ratio such as the crankcase ventilation system, the car-

buretor and the carburetor air cleaner. Carburetors and

distributors for engines with the Air Injection Reactor

System are designed, particularly, for these engines;

therefore, they must not be interchanged with or replaced

by a carburetor or distributor designed for an engine

without the Air Injection Reactor System.

Choke Adjustment (Fig. 11)

With Remote Choke

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke r*od at choke lever.

Check choke adjustment as follows:

On all except 275 hp 327 cu. in. engines, hold

choke valve closed and pull rod up against stop. The

top of choke rod end should be 1/2 - 1 rod diameter
4.

5.
above top of hole in choke valve lever.

On 275 hp 327 cu. in. engines, hold choke valve

closed and push rod down against stop on thermostat

bracket. The top of the choke rod should be 1/2 - 1

rod diameter below the top of the hole in the choke

lever.

If necessary, adjust rod length by bending rod at off-

set. (Bend must be such that rod enters choke lever

hole freely and squarely.)

Connect rod at choke lever and install air cleaner.

3.
With Manual
Choke

1.
Remove air cleaner.

2.
Push hand choke knob in to within 1/8" of instrument

panel.

3.
Loosen choke cable at carburetor bracket and adjust

cable through the clip until the choke valve is wide

open.

4.
Tighten cable clamp at carburetor bracket and check

operation of choke valve to ensure full closed and

wide open positions.

INSTRUMENT CHECK-OUT

Instrument Hook Up

Connect vacuum gauge, dwell meter, tachometer and

timing light as recommended by the manufacturer of the

equipment being used.

Check and Adjust Dwell

1.
Start engine then ch^ck ignition dwell.

.2.
If dwell is not within specifications, adjust dwell as

follows:

V8 ENGINES

• With engine running at idle, raise the adjustment

screw window-and insert an Allen wrench in the

socket of the adjusting screw (fig. 12).

• Turn the adjusting screw as required until a dwell

reading of 30° is obtained. A 2° variation is al-

lowable for wear.

• Close access cover fully to prevent the entry of

dirt into the distributor.

NOTE: If a dwell meter is not available, turn
adjusting screw clockwise until engine starts to

misfire, then turn screw one-half turn in the op-

posite direction to complete adjustment.

IN LINE ENGINES

• Remove distributor cap and recheck point setting.

If dwell is still not within specifications check the

distributor as outlined in Section 6Y.

Check Dwell Variation

Slowly accelerate engine to 1500 rpm and note dwell

reading. Return engine to idle and note dwell reading. If

dwell variation exceeds specifications, check for worn

distributor shaft, worn distributor shaft bushing or loose

breaker plate.

WINDOW

"HEX" TYPE

WRENCH

Fig.
12 - Setting Point Dwell (V8)
Fig.
13 - Ignition Timing Marks

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 6-16

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

ENGINE 6-19

OIL SEAL (REAR MAIN)

Replacement

The rear main bearing oil seal can be replaced (both

halves) without removal of the crankshaft.

NOTE:
Always replace the upper and lower

seal as a unit. Install with the lip facing toward

the front of the engine.

1.
With the oil pan removed, remove the rear main

bearing cap.

2.
Remove oil seal from the groove by lifting the end

tab (fig. 7L) then clean seal groove.

3.
Lubricate the lip and O.D. of a new seal with engine

oil. Keep oil off the parting line surface. Insert

seal in cap and roll it into place with finger and

thumb,
using light pressure so beads on seal O.D.

are not cut by seal groove at cap parting line. Be

sure tabs on seal are properly located in cross

grooves.

4.
To remove the upper half of the seal, use a small

hammer to tap a brass pin punch on one end of seal

until it protrudes far enough to be removed with

pliers (fig. 8L).

NOTE:
Always clean crankshaft surface re-

moving all foreign deposits before installing a

new seal. Also clean seal groove.

5. Lubricate the lip and O.D. of a new seal with engine

oil. Keep oil off the parting line surface. Gradually

push with a hammer handle, while turning crank-

shaft, until seal is rolled into place. (Similar to in-

stalling a main bearing.) Be careful that seal bead

on O.D. is not cut. Compress seal towards crank-

shaft as much as possible.

6. Install the rear main bearing cap (with new seal) and

torque to specifications. Be sure cross seal tabs

are in place and properly seated.

CRANKSHAFT PULLEY AND HUB

(Chevy II with L4 Engine)

Removal

1.
Drain radiator and disconnect upper and lower radi-

ator hoses at radiator.

2.
Remove radiator core as outlined in Section 13.

3.
Remove fan belt. Remove crankshaft pulley from

pulley hub.

4.
Install puller Tool J-6978 to pulley hub with two

3/8"
x 2" and one 5/16" x 2" bolts and remove hub

then remove puller tool.

Installation

1.
Coat oil seal contact area on hub with engine oil

position hub over crankshaft and key and start hub

into position with a mallet. Using Tool J-5590 drive

onto crankshaft until it bottoms against crankshaft

gear.

NOTE:
Crankshaft extends slightly through hub

and a tool is necessary to drive hub completely

into bottomed position.

2.
Install pulley onto hub.

NOTE:
There are two 3/8" holes and one

5/16" hole that must be matched on hub in order
Fig.
9L - Removing Torsional Damper

to properly position timing mark.

3.
Install fan belt and adjust using strand tension gauge.

4.
Install radiator as outlined in Section 13.

TORSIONAL DAMPER

Removal

1.
Remove radiator core, as outlined in Section 13.

2.
Remove fan belt and (if so equipped) accessory drive

pulley and belt.

3.
Install Tool J-6978 to damper and turn puller screw

to remove damper (fig. 9L). Remove tool.

Installation

1.
Coat front cover oil seal contact area of damper with

engine oil.

CAUTION: It is necessary to use installer

Tool J-22197 to prevent the inertia weight sec-

Fig.
10L - Installing Torsional Damper

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-29

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 ab-

normal stickiness.

b.
(Sailing or "pick-up" 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-rThis

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, disassembled, cleaned

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

If dirt, corrosion, 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 intake manifold as outlined.

2.
Remove valve mechanism as outlined.

3.
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 intake manifold as outlined.

3.
Install and adjust valve mechanism as outlined.

VALVE STEM OIL SEAL AND/OR VALVE SPRING

Replacement

1.
Remove rocker arm cover(s) as outlined.

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

cylinders to be serviced.

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

tl*e 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 plug and assem-

ble as shown (fig. 6V).
Fig.
6V - Air Adapter Tool

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

move the valve locks, valve cap, and valve spring and

damper (fig. 7V).

5.
Remove valve stem oil seal.

6. Remove as follows:

283, 327 and 350 eu. in.
Engines

a. 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.

b.
Compress the spring with Tool 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.

Fig.
7V - Compressing Valve Spring

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-32

Fig.
1GV - Removing Oil Seal (Lower Half)

bearing cap, aligning slot on top end of extension

shaft with drive tang on lower end of distributor

drive shaft.

2.
Install pump to rear bearing cap bolt and torque to

specifications.

NOTE:
Installed position of oil pump, screen

is with bottom edge parallel to oil pan rails.

3.
Install oil pan as outlined.

OIL SEAL (REAR MAIN)

Replacement

The rear main bearing oil seal can be replaced (both

halves) without removal of the crankshaft.
Fig.
12V - Removing Torstonal Damper

NOTE:
Always replace the upper and lower

seal as a unit.. Install with the lip facing toward

the front of the engine.

With the oil pan and oil pump removed, remove the

rear main bearing cap.

Remove oil seal from the groove by prying from the

bottom with a small screw driver (fig. 10V).

Lubricate the lip of a new seal with engine oil. Keep

oil off the parting line surface as this is treated with

glue. Insert seal in cap and roll it into place with

finger and thumb, using light pressure so seal tangs

at parting line do not cut bead on back of seal.

To remove the upper half of the seal, use a small

hammer to tap a brass pin punch on one end of seal

until it protrudes far enough to be removed with

pliers (fig. 11V).

NOTE:
Always wipe crankshaft surface clean

before installing a new seal.
1.

2.

3.

5.

Fig.
1IV - Removing Oil Seal (Upper Half)
Lubricate the lip of a new seal with engine oil. Keep

oil off the parting line surface as this is treated with

glue. Gradually push with a. hammer handle, while

turning crankshaft, until seal is rolled into place.

(Similar to installing a main bearing.) Be careful

that seal tangs at parting line do not cut bead on back

of seal.

6. Install the rear main bearing cap (with new seal) and

torque to specifications.

TORSIONAL DAMPER

Removal

1.
Remove fan belt, fan and pulley as outlined in Sec-

tion 6K.

2.
Remove the radiator and shroud as outlined in Sec-

tion 13.

NOTE:
If additional operations such as cam-

shaft removal are not being performed, the radi-

ator will not have to be removed
.on
Chevrolets

and Corvettes equipped with 396 and 427 cu. in.

engines.

. 3. On Corvettes equipped with 427 cu. in. engines, re-

move engine front mount through-bolts and raise

front of engine enough for torsional damper to clear

frame crossmember.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-35

Fig.
19V - installing Oil Seal (Cover Installed)

396 and 427

TIMING CHAIN AND/OR SPROCKETS

Replacement

1.
Remove torsionai damper and crankcase front cover

as outlined.

2.
Crank engine until marks on camshaft and crankshaft

sprockets are in alignment (fig. 20V).

3.
Remove three camshaft sprocket to camshaft boltg.

4.
Remove camshaft sprocket and timing chain together.
Fig.
21V - Removing Crankshaft Sprocket

(283,
327 and 350)

NOTE: Sprocket is a light press fit on cam-

shaft. To dislodge, tap lightly on lower edge of

camshaft sprocket with a plastic hammer.

5.
If crankshaft sprocket is to be replaced, remove

sprocket using Tool J-5825 on 283, 327 and 350

cu. in. engines (fig. 21V) or Tool J-1619 on 396 and

427 cu. in. engines (fig. 22V). Install new sprocket

using Tool J-5590 on 283, 327 and 350 cu. in. engines

- (fig. 23V) or Tool J-21058 on 396 and 427 cu. in.

engines (fig. 24V).

6. Install timing chain on camshaft sprocket. Hold the

sprocket vertical with the chain hanging below, and

orient to align marks on camshaft and crankshaft

sprockets (fig. 20V).

7.
Align dowel in camshaft with dowel hole in camshaft

sprocket and install sprocket on camshaft (fig. 25V).

NOTE: Do not attempt to drive cam sprocket

on shaft as welsh plug at rear of engine can be

dislodged.

WASHER

(TORSIONAL DAMPER)

Fig.
20V - Timing Sprocket Marks
Fig.
22V - Removing Crankshaft Sprocket (396 and 427)

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-37

Fig.
27V—Removing Camshaft

4.
Set dial indicator on zero, then rotate the damper

slowly, or attach an auxiliary starter switch and

"bump" the engine over, until the push rod is in the

fully raised position.

CAUTION: The primary distributor lead must

be disconnected from the negative post on the

coil and the ignition switch must be in the on

position. Failure to do this will result in a dam-

aged grounding circuit in the ignition switch.

5.
Compare the total lift recorded from the dial indica-

tor with specifications.

6. Continue to rotate the crankshaft until the indicator

reads zero. This will be a check on the accuracy of

the original indicator reading.

7.
If camshaft readings for all lobes are within specifi-

cations, remove dial indicator assembly.

8. Install and adjust valve mechanism as outlined.

Removal

1.
Remove valve lifters as outlined.

2.
Remove crankshaft front cover as outlined.

3.
Remove grille as outlined in Section 13.

4.
Remove fuel pump push rod as outlined * in Sec-

tion 6M.

5.
Complete camshaft removal as follows:

CAUTION: All camshaft journals are the same

diameter and care must be used in removing

camshaft to avoid damage to bearings.

Remove camshaft sprocket to camshaft bolts then

remove sprocket and timing chain together. Sprocket

is a light fit on camshaft. If sprocket does not come

off easily a light blow on the lower edge of the

sprocket (with a plastic mallet) should dislodge the

sprocket.

Install two 5/16" - 18 x 4" bolts in camshaft bolt

holes then remove camshaft (fig. 27V).

Installation

NOTE: Whenever a new camshaft is installed
CONVERTER

BOLT AREA -

DEPRESSED

SYNCHROMESH
RING

GEAR

TRANS.,

AUTOMATIC

Fig.
28V - Flywheel Installation (Typical)

coat camshaft lobes with Molykote or its

equivalent.

1.
Lubricate camshaft journals with engine oil and in-

stall camshaft.

2.
Install timing chain on camshaft sprocket. Hold the

sprocket vertical with the chain hanging down, and

orient to align marks on camshaft and crankshaft

sprockets. Refer to Figure 20V.

3.
Align dowel in camshaft with dowel in hole in cam-

shaft sprocket then install sprocket on camshaft.

Refer to Figure 25V.

4.
Draw the camshaft sprocket onto camshaft using the

mounting bolts. Torque to specifications.

5.
Lubricate timing chain with engine oil.

6. Install fuel pump push rod as outlined in Section 6M.

7.
Install grille as outlined in Section 13.

8. Install crankcase front cover as outlined.

9. Install valve lifters as outlined.

FLYWHEEL

Removal

With transmission and/or clutch housing and clutch

removed from engine, remove the flywheel.

Installation

1.
Clean the mating surfaces of flywheel and crankshaft

to make certain there are no burrs.

2.
Install flywheel on crankshaft and position to align

dowel hole of crankshaft flange and flywheel (fig.

28V).

NOTE: On Automatic Transmission equipped

engines, the flywheel must be installed with the

flange collar to transmission side (fig. 33V).

ENGINE MOUNTS

Engine mounts (fig. 34V) are the nonr adjustable type

and seldom require service. Broken or deteriorated

mounts should be replaced immediately, because of the

added strain placed on other mounts and drive line

components.

Front Mount Replacement

1.
Remove nut, washer and engine mount through-bolt.

2.
Raise engine to release weight from mount.

3.
Remove mount from engine.

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 6M

ENGINE FUEL

CONTENTS OF THIS SECTION

Page

Carburetors 6M-1 Fuel Pumps .

Air Cleaners 6M-7 Special Tools
Page

6M-10

6M-12

CARBURETORS

INDEX

Page

General Description 6M-1

Service Procedures 6M-1

Preliminary Checks 6M-1

Idle Speed and Mixture Adjustment ........... 6M-1

Fast Idle Adjustment .................. 6M-3

Choke Adjustment 6M-3

Float Adjustment 6M-4
Page

Additional Adjustments 6M-4

Removal 6M-4

Test Before Installation 6M-5

Installation 6M-5

Fuel Filter Maintenance 6M-5

Choke Coil Replacement 6M-5

Throttle Linkage Adjustment . . 6M-6

GENERAL DESCRIPTION

Various carburetors (fig. lc) are used with Chevrolet,

Chevelle, Chevy II, Camaro and Corvette passenger

vehicles. These carburetors are designed to meet the

particular requirements of engines, transmissions and

vehicles, therefore carburetors that look alike are not

always interchangeable. (Refer to carburetor part num-

ber and/or specifications.)

Because many service procedures for the various

carburetors are similar, typical illustrations and pro-

cedures are used except where specific illustrations or
procedures are necessary to clarify the operation.

This section covers removal, installation and adjust-

ments (on engine) of carburetors. Also covered in this

section are maintenance procedures for choke coils,

throttle linkage and fuel filters. For carburetor .over-

haul procedures and additional adjustments (bench), re-

fer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Specifications for carburetors are located in the back

of this manual.

SERVICE PROCEDURES

Preliminary Checks

1.
Thoroughly warm-up engine. If the engine is cold,

allow to run for at least 15 minutes.

2.
Inspect torque of carburetor to intake manifold bolts

and intake manifold to cylinder head bolts to exclude

the possibility of air leaks.

3.
Inspect manifold heat control valve (if used) for free-

dom of action and correct spring tension.

Idle Speed and Mixture Adjustment (Except Air Injection

Reactor System)

NOTE:
This adjustment should be performed

with engine at operating temperature and park-

ing brake applied.

1.
Remove Air Cleaner.

2.
Connect tachometer and vacuum gauge to engine, then

set hand brake and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 1-1/2 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result.

4.
With engine running (choke wide open) adjust idle
speed screw to specified idle speed, (automatic

transmission in drive, synchronized transmission in

neutral).

5. Adjust idle mixture screw to obtain highest steady

vacuum at specified idle speed.

NOTE:
On air conditioned vehicles, turn air

conditioning to the "on" position and hold the

hot idle compensator valve closed while adjust-

ing idle speed and idle mixture screws.

NOTE:
On Rochester BV carburetors the idle

mixture screw should be turned out 1/4 turn

from the "lean roll" position. The definition

of "lean roll" point is a 20 to 30 rpm drop

in engine speed obtained by leaning the idle

mixture.

6. Repeat Steps 4 and5 as needed for final adjustment.

NOTE:
If necessary, final adjustment of the \

carburetor may be made with the air cleaner

installed.

7. Turn engine off, remove gauges and install air

clearer.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-3

Idle Speed and Mixture Adjustment (With Air Injection

Reactor System)

The following is the recommended procedure for Air

Injection Reactor System equipped engines.

NOTE: This adjustment should be performed

with engine at operating temperature and parking

brake applied.

1.
Remove air cleaner.

2.
Connect tachometer to engine, then set hand brake

and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 3 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result."

4.
With engine running (choke wide open) adjust idle

speed screw to specified idle speed. (Automatic

transmission in dirve, synchronized transmission in

neutral).

5.
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.

NOTE: On air conditioned vehicles, turn air

conditioning "OFF" on in-line, 283, 327, and'

350 cu. in. engines, and turned "ON" and hot

idle compensator held closed on 396 and 427 cu.

in. engines.

6. Repeat Steps 4 and 5 as needed for final adjustment.

NOTE: If necessary, final adjustment of the
carburetor may be made with air cleaner

installed.

7.
Shut down the engine, remove gauges and install air

cleaner. *

Fast Idle Adjustment

Rochester
4MV and Holley

With fast idle lever on high step of cam and choke valve

open (engine warm) set fast idle to give specified engine

rpm. Adjust sejrew on Rochester 4MV and bend fast

idle lever *pn Holley. .

Choke Adjustment

With Remote Choke (Fig. 2c)

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke rod at choke lever.

3.
Check choke adjustment as follows:

On all except 275 and 300 h.p. 327 cu. in. engines,

hold choke valve closed and pull.rod up against stop.

The top of choke rod end should be 1/2-1 rod diame-

ter above top of hole in choke valve lever.

On 275 and 300 h.p. 327 cu. in. engines, hold choke

valve closed and push rod down against stop on ther-

mostat bracket. The top of the choke rod should be

1/2-1 rod diameter below the top of the hole in the

choke lever.

4.
If necessary, adjust rod length by bending rod at

offset bend. (Bend must be such that rod enters

choke lever hole freely and squarely).

5.
Connect rod at choke lever and install air cleaner.

With Manual Choke (Carter YF)

1.
Remove air cleaner.

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

BE EVEN WITH

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 ROD

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
2C—Remote Choke Adjustment

CHEVROLET CHASSIS SERVICE MANUAL