ENGINE 6-26
6. Remove lifting device and lifting adapter then install
rocker arm covers 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.
• Transmission cooler lines (if so equipped).
9. Install propeller shaft.
10.
Remove jack stands and lower vehicle.
11.
Connect: \ '
Power steering pump lines (if so equipped).
Vacuum line to power brake unit (if so equipped).
Exhaust pipes at manifold flanges.
Accelerator linkage at pedal lever.
Fuel line at fuel pump.
Engine cooler lines (if so equipped).
Oil pressure gauge lines (if so equipped).
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.
INTAKE MANIFOLD
Removal
1.
Drain radiator and remove air cleaner.
2.
Disconnect:
Battery cables at battery.
Upper radiator and heater hose at manifold.
Accelerator linkage at pedal lever.
Fuel line at carburetor. ;
Wires at temperature sending switch and coil
(both sides).
Power brake hose at carburetor base.
Spark advance hose at distributor.
Crankcase ventilation hoses (as required).
3.
Remove distributor cap and mark rotor position with
chalk. Remove distributor clamp and distributor,
then position distributor cap rearward clear of
manifold.
4.
Remove coil.
5.
Remove manifold-to-head attaching bolts, then re^
move manifold, (with carburetor on) from engine and
discard gaskets and seals.
6. If manifold is to be replaced,,transfer:
Carburetor and carburetor mounting studs.
Temperature sending switch.
Water outlet and thermostat (use new gasket).
Heater hose adapter.
Choke coil.
Installation
1.
Clean gasket and seal surfaces of manifold, cylinder
heads and block.
2.
Install manifold end seals on block as shown (fig.
2V).
3.
Install side gaskets on cylinder heads using sealing
compound around water passages (fig. 2V).
4.
Install manifold bolts, and torque to specifications in
the sequence outlined on the Torque Sequence Chart.
5.
Install coil.
6. Install distributor with the rotor pointing at the chalk
mark, then install distributor cap.
NOTE:
If the crankshaft has been rotated while
the distributor was removed, time distributor to
number 1 cylinder as outlined in Section 6Y.
7.
Connect:
Battery cables at battery.
Upper radiator and heater hose at manifold.
Accelerator linkage at pedal lever.
Fuel line at carburetor.
Wires at temperature sending switch and coil
(both sides)!
Power brake hose at carburetor base.
Spark advance hose at distributor.
Crankcase ventilation hoses (as required).
Fill with coolant, start engine, check for leaks and
adjust timing and carburetor idle speed and mixture.
EXHAUST MANIFOLD
Removal
NOTE:
If equipped with "Air Injection Reactor
System", remove air manifold and tubes as out-
lined in Section 6T.
1.
Disconnect battery ground cable.
-
2.
Disconnect and remove Delcotron (as required).
3.
On 396 and 427 cu. in. engines, remove spark plugs
Fig. 2V - Intake Manifold Gasket and Seal Location
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-2
ROCHESTER
BV
IDLE
SPEED
IDLE
MIXTURE
ROCHESTER
2GV
HOLLEY 2300C
(PRIMARY)
IDLE
MIXTURE
SPEED
HOLLEY 2300
(SECONDARY)
IDLE IDLE
MIXTURE SPEED
MANUAL
CHOKE CART
R YF
AUTOMATIC CHOKE
IDLE
SPEED
IDLE
MIXTURE
IDLE
MIXTURE
IDLE
SPEED
ROCHESTER
4MV
IDLE
SPEED
IDLE
MIXTURE
SIDE INLET
HOLLEY
4150
CENTER INLET
IDLE
MIXTURE
IDLE
MIXTURE
IDLE
SPEED
HOLLEY
4160
IDLE
MIXTURE
IDLE
SPEED
APPLICATION
CARBURETOR
U
IN LINE
153
90
194
120
230
140
250
155
V-8
283
195
210
327
275 300 325 350
350
295
396
325 350
427
385 390 400 425 435
ROCH.
BV
1234
ROCH
2GV
1234
ROCH
4MV
1234
1-2
CARTER
YF
Man.
Auto.
2-4
1234
HOLLEY
4150
Side
Center
HOLLEY
4160
HOLLEY
2300
C Prim.
Sec.
Fig.
1C
—Carburetors
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
ENGINE FUEL 6M-4
Fig.
3C-Fuel Level Sight Plug
2.
Push hand choke knob in to within 1/8" of instru-
ment panel.
3.
Loosen choke cable clamp 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.
5. Install air cleaner.
Float Adjustment
Ho/fey (Model 4150
Center
Inlet & Model 2300)
1.
Remove air cleaner then remove the fuel level sight
plugs (Fig. 3c)
2.
With parking brake on, and transmission in neutral,
start the engine and allow it to idle.
3.
With the car on a level surface, the fuel level should
be on a level with the threads at the bottom of the
sight plug port (plus or minus 1/32 inch).
NOTE:
No float drop adjustment is required
on this carburetor.
4.
If necessary to adjust (either or both bowls), loosen
inlet needle lock screw and turn the adjusting nut
clockwise to lower or counter-clockwise to raise
fuel level, then tighten lock screw.
NOTE:
1/6 turn of adjusting nut equals ap-
proximately 1/16" fuel level change.
5. Allow a minute for fuel level to stabilize then re-
check the level at sight plug.
6. Readjust, if necessary, until proper level is obtained,
then install sight plug and air cleaner.
NOTE:
To assure proper secondary float level
setting it is advisable to accelerate primary
throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary
fuel level.
Additional Adjustments
The following adjustments may be made without re-
moving the carburetor from the engine. For procedure
refer to Section 6M of the Overhaul Manual under the
carburetor being serviced.
Rochester BV
• Float
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
Rochester 2GV
• Float
• Accelerator Pump
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
• Secondary Throttle Opening
• Secondary Throttle Lockout
Rochester 4MV
• Float
• Accelerator Pumj)
• Idle Vent
• Air Valve
• Choke Rod
• Choke Vacuum Break
• Choke Unloader
• Air Valve Lockout
• Secondary Opening
• Secondary Lockout
Carter YF
• Float
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
Holley 4160 and 4150
(Except End
Inlet)
• Float
• Air Vent Valve
• Accelerator Pump
• Choke Vacuum Break
• Choke Unloader
Holley 2300 and 4150
(End
Inlet)
• Air Vent Valve (except 2300)
• Accelerator Pump
• Choke Vacuum Break
• Choke Unloader
Removal
Flooding, stumble on acceleration and other perform-
mance complaints are, in many instances, caused by the
presence of dirt, water, or other foreign matter in the
carburetor. To aid in diagnosing the cause of the com-
plaint, the carburetor should be carefully removed from
the engine without draining the fuel from the bowl.
The contents of the fuel bowl may then be examined for
contamination as the carburetor is disassembled.
1.
Remove air cleaner and gasket.
2.
Disconnect fuel and vacuum lines from carburetor.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-5
3.
Disconnect choke rod or choke cable.
4.
Disconnect accelerator linkage.
5.
If equipped with Automatic transmission, discon-
nect TV linkage.
6. Remove carburetor attaching nuts and/or bolts and
remove carburetor.
Test Before Installation -
It is good shop practice to fill the carburetor bowl
before installing the carburetor. This reduces the strain
on the starting motor and battery and reduces the pos-
sibility of backfiring while attempting to start the engine.
A fuel pump clamped to the bench, a small supply of fuel
and the necessary fittings enable the carburetor to be
filled1 and the operation of the float and'intake needle and
seat to be checked. Operate the throttle several times
and check the discharge from the pump jets before in-
stalling the carburetor.
Installation
1.
Be certain throttle body and intake manifold sealing
surfaces are clean.
2.
Install new carburetor to manifold flange gasket (if
required).
3.
Install carburetor over manifold studs.
4.
Start vacuum and fuel lines at carburetor.
5.
Install attaching nuts and/or bolts and tighten
securely.
6. Tighten fuel and vacuum lines.
7.
Connect and adjust accelerator and TV linkage.
8. Connect choke tube or choke rod.
9. Adjust idle speed and mixture, then install air
cleaner. #
Fuel Filter Maintenance
1.
Disconnect fuel line connection at inlet fuel filter
nut.
2.
Remove inlet fuel filter nut from carburetor with a
1"
box wrench or socket.
3.
Remove filter element and spring (fig. 4c).
Fig. 5C-Choke Coil-L6 Engine
4.
Fig. 4C-Fuel Filter
Check element for restriction by blowing on cone
end, element should allow air to pass freely.
5.
Clean element by washing in solvent and blowing out.
Blow in opposite direction of fuel flow.
NOTE: Element should be replaced if plugged
or if flooding ocpurs. A plugged filter will
result in a loss of engine power or rough (pul-
sating) engine feel, especially at high engine
speeds.
6. Install element spring, then install element in car-
buretor so small section of cone faces out.
7.
Install new gasket on inlet fitting nut then install
nut in carburetor and tighten securely.
8. Install fuel line and tighten connector.
Choke Coil Replacement
L6 Engines (Fig. 5c)
1.
Remove air cleaner then disconnect choke rod upper
clip.
2.
Remove bolts attaching choke coil to manifold, then
remove choke coil and choke rod as an assembly.
3.
Disconnect choke rod from choke coil.
4.
Connect choke rod to new choke coil and install as-
sembly on manifold.
5.
Install bolts and tighten securely.
6. Adjust and connect choke rod as outlined.
7.
Start and warm-up the engine then check operation
of choke and install air cleaner.
V8 Engines (Fig. 6c)
1.
Remove air cleaner then disconnect choke rod upper
clip.
2.
Remove choke coil as follows:
WITH ROCHESTER 2GV CARBURETOR
• Remove the choke coil shield by prying with a
screw driver in the cut out provided then re-
move the choke rod.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-6
Fig.
6C-Choke Coil-V8 Engine
• Remove bracket and choke coil assembly.
WITH ROCHESTER 4MV AND
HOLLEY CARBURETORS
• Remove the choke coil shield by prying with a
screw driver in the cut out provided then lift
shield carefully over rod.
• Remove choke rod, bracket screw and choke
coil assembly
3.
Install a new choke coil assembly being sure the
locating tab is in the forward hole of the intake
manifold then install mounting screw.
4.
Complete installation as follows:
WITH ROCHESTER 2GV CARBURETOR
• Check that the choke rod eye of the coil is
below the stop tab on the bracket then install
the choke
ro
• Install the choke coil shield over the choke coil
and move shield to best fit along manifold.
WITH ROCHESTER 4MV AND
HOLLEY CARBURETORS
• Install the choke rod and adjust as necessary
(without choke coil shield installed).
• Disconnect choke rod upper end and lower choke
coil shield over choke rod and install over choke
coil.
• Move shield to best fit along manifold and con-
nect upper end of choke rod.
5. Be sure choke valve moves freely from full open
to full closed position.
6. Start and warm up the engine and check operation
of the choke.
7. Install the air cleaner.
Throttle Linkage Adjustment (Fig. 7c or 8c)
1.
Disconnect throttle rod swivel at throttle lever on
carburetor.
2.
On automatic transmission equipped vehicles dis-
connect TV rod at throttle lever.
3.
Hold carburetor throttle in wide open position, push
throttle rod rearward (to position accelerator pedal
at the floor mat) and adjust swivel to just enter hole
in throttle lever.
4.
Connect swivel to throttle lever and install accelera-
tor return spring.
CAMARO & CHEVY II V8
CHEVELLE & CHEVROLET
V8
CAMARO
&
CHEVY
II
V8
CHEVELLE &
CHEVROLET V8
ALL SERIES
IN LINE
ALL SERIES
INLINE
Fig.
7C—Throttle Linkage—Chevrolet, Chevelle, Chevy II and Camaro
CHEVROLET CHASSIS SERVICE MANUAL