
ENGINE 6-21
CAUTION: Support cover
•
at sealing area.
(Tool J-971 may be used as support.)
Without Cover
Removal
1.
With crankshaft pulley and nub or torsional damper
removed, pry old seal out of cover from the front
with a large screw driver, being careful not to dam-
age the seal surface on the cover.
2.
Install new seal so that open end of seal is toward the
inside of cover and drive it into position with Tool
J-8340 (fig. 13L).
CAMSHAFT
Measuring Lobe Lift
NOTE: Procedure is similar to that used for
checking valve timing.. If improper valve
operation is indicated, measure the lift of each
push rod in consecutive order and record the
readings.
1.
Remove valve mechanism as outlined.
2.
Position indicator with ball socket adapter on push
rod (fig. 14L).
3.
Rotate the crankshaft slowly in the direction of rota-
tion until the lifter is on the heel of the cam lobe.
At this point, the push rod will be in its lowest
position.
4.
Set dial indicator on zero, then rotate the crankshaft
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
damaged grounding circuit in the ignition switch.
Fig.
15L - Timing Gear Marks
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 crankcase front cover as outlined.
3.
Remove radiator as outlined in Section 13.
4.
Remove grille as outlined in Section 13.
5.
Remove fuel pump as outlined in Section 6M.
6. Align timing gear marks then remove the two cam-
shaft thrust plate bolts by working through holes in
Fig.
ML - Measuring Camshaft Lobe Lift
Fig.
16L - Checking Camshaft Gear Runout
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-25
refer to Section 6 of the Chassis Overhaul Manual.
Because of the interchangeability and similarity of
many engines, engine sub-assemblies and engine parts,
regardless of which passenger vehicle they are used in,
typical illustrations and procedures are used except
where specific illustrations or procedures are necessary
to clarify the operation. Although illustrations showing
bench operations 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
battery.
3.
Remove hood as outlined in Section 11.
4.
Remove radiator and shroud as outlined in Sec-
tion 13.
5. Remove fan blade and pulley as outlined in Sec-
tion 6K.
6. Disconnect wires at:
• Starter solenoid
• Delcotron
• Temperature switch
• Oil pressure switch
• Coil
7. Disconnect:
• Accelerator linkage at pedal lever.
• Exhaust pipes at manifold flanges.
• Vacuum line to power brake unit at manifold (if
so equipped),
• Power steering pump lines at pump end (if so
equipped).
• Fuel line (from tank) at fuel pump.
• Engine cooler lines (if so equipped).
• Oil pressure gauge line (if so equipped).
8. Raise vehicle and place on jack stands.
9. Remove propeller shaft.
NOTE:
If plug for propeller shaft opening
in transmission is not available, drain
transmission.
10.
Disconnect:
• Shift linkage at transmission.
• Speedometer cable at transmission.
• Transmission cooler lines (if so equipped).
11.
On synchromesh equipped vehicles, disconnect clutch
linkage at cross-shaft then remove cross-shaft en-
gine bracket.
12.
Remove rocker arm covers as outlined, then attach
engine lifting adapter at the proper cylinder head bolt
locations.
13.
Remove front mount bolts.
14.
Attach lifting device and raise engine to take weight
off front mounts, then remove rear mount bolts.
15.
Raise engine to take weight off rear mount, then re-
move crossmember.
NOTE:
On Chevrolets it will be necessary to
remove mount from transmission before cross-
member can be removed.
16.
Remove engine-transmission assembly from vehicle
as a unit.
17.
Remove transmission (and clutch):
Synchromesh Transmission
a. Remove clutch housing cover plate screws.
b.
Remove bolts attaching the clutch housing to en-
gine block then remove transmission and clutch
housing as a unit.
NOTE:
Support the transmission as the last
mounting bolt is removed, and as it is being
pulled away from the engine (to prevent damage
to clutch disc).
c. Remove starter and clutch housing rear cover
plate.
d. Loosen clutch mounting bolts a turn at a time (to
prevent distortion of clutch cover) until the spring
pressure is released. Remove all bolts, clutch
disc and pressure plate assembly.
Automatic
Transmission
a. Lower engine, secured by the hoist, and support
engine on blocks.
b.
Remove starter and converter housing underpan.
c. Remove flywheel-to-converter attaching bolts.
d. Support transmission on blocks.
e. Remove transmission-to-engine mounting bolts.
f. With the hoist attached, remove blocks from the
engine only and slowly guide the engine from the
transmission.
18.
Mount engine in stand.
Installation
1.
Attach lifting device to engine and remove engine
from engine stand.
2.
Install transmission (and clutch):
Synchromesh Transmission
a. Install the clutch on flywheel as outlined in Sec-
tion 7.
b.
Install clutch housing rear cover and starter.
c. Install transmission and clutch housing as out-
lined in Section 7.
d. Install clutch housing cover screws and tighten
securely.
Automatic
Transmissions
a. Position engine adjacent to the transmission and
align the converter with the flywheel.
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 bolts and torque to specifications.
5. Raise engine enough to install rear crossmember,
then install crossmember, install rear mount, lower
engine and torque rear mount to specifications.
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-36
Fig.
23V - Installing Crankshaft Sprocket
(283,
327
and
350)
8* Draw camshaft sprocket onto camshaft, using the
three mounting bolts. Torque to bolt specifications.
9. Lubricate timing chain with engine oil.
10.
Install crankcase front cover and torsional damper
as outlined.
CAMSHAFT
Measuring Lobe Lift
NOTE: Procedure is similar to that used for
checking valve timing. If improper valve opera-
tion is indicated, measure the lift of each push
rod in consecutive order and record the
readings.
1.
Remove valve mechanism as outlined.
2.
Position indicator with ball socket adapter on push
rod (fig. 26V).
3.
Rotate the crankshaft damper slowly in the direction
of rotation until the lifter is on the heel of the cam
lobe.
At this point, the push rod will be in its lowest
position.
Fig.
25V- Installing Timing Chain
Fig.
24V - Installing Crankshaft Sprocket
(396 and 427)
Fig.
26V - Measuring Camshaft Lobe Lift
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-2
are indicative of exhaust gases leaking into the coolr
ing system.
Periodic Maintenance
Periodic service must be performed to the engine cool-
ing system to keep it in efficient operating condition.
These services should include a complete cleaning and
reverse flushing as well as a reconditioning service.
In the course of engine operation, rust and scale ac-
cumulate in the radiator and engine water jacket. The
accumulation of these deposits can be kept to a minimum
by the use of a good rust inhibitor but it should be
remembered that an inhibitor will not remove rust al-
ready present in the cooling system.
Two common causes of corrosion are: (1) air suction--
Air may be drawn into the system due to low liquid level
in the radiator, leaky water pump or loose hose con-
nections; (2) exhaust gas leakage—Exhaust gas may be
blown into the cooling system past the cylinder head
gasket or through cracks in the cylinder head and block.
Cleaning
A good cleaning solution should be used to loosen the
rust and scale before reverse flushing the cooling
system. There are a number of cleaning solutions avail-
able and the manufacturer's instructions with the particu-
lar cleaner being used should always be followed.
An excellent preparation to use for this purpose is GM
Cooling System Cleaner. The following directions for
cleaning the system applies only when this type cleaner
is-used.
1.
Drain the cooling system including the cylinder block
and then close both drain plugs.
2.
Remove thermostat and replace thermostat housing.
3.
Add the liquid portion (No. 1) of the cooling system
cleaner.
4.
Fill the cooling system with water to a level of about
3 inches below the top of the overflow pipe.
5. Cover the radiator and run the engine at moderate
speed until engine coolant temperature reaches 180
degrees.
6. Remove cover from radiator and continue to run the
engine for 20 minutes. Avoid boiling.
7. While the engine is still running, add the powder
portion (No. 2) of the cooling system cleaner and
continue to run the engine for 10 minutes.
8. At the end of this time, stop the engine, wait a few
minutes and then open the drain cocks or remove
pipe plugs. Also remove lower hose connection.
CAUTION: Be careful not to scald your hands.
NOTE:
Dirt and bugs may be cleaned out of
the radiator air passages by blowing out with air
pressure from the back of the core.
Reverse Flushing
Reverse flushing should always be accomplished after
the system is thoroughly cleaned as outlined above.
Flushing is. accomplished through the system in a direc-
tion opposite to the normal flow. This action causes the
water to get behind the corrosion deposits and force
them out.
Radiator
1.
Remove the upper and lower radiator hoses and re-
place the radiator cap,
2.
Attach a lead-away hose at the top of the radiator.
3.
Attach a new piece of hose to the radiator outlet
connection and insert the flushing gun in this hose.
4.
Connect the water hose of the flushing gun to a water
outlet and the air hose to an air line.
5. Turn on the water and when the radiator is full, turn
on the air in short blasts, allowing the radiator to
fill between blasts of air.
CAUTION: Apply air gradually as a clogged
radiator will stand only a limited pressure.
6. Continue this flushing until the water from the lead-
away hose runs clear.
Cylinder Block and Cylinder Head
1.
With the thermostat removed, attach a lead-away
hose to the water pump inlet and a length of new hose
to the water outlet connection at the top of the engine.
NOTE:
Disconnect the heater hose when re-
verse flushing engine.
2.
Insert the flushing gun in the new hose.
3.
Turn on the water and when the engine water jacket
is full, turn on the air in short blasts.
4.
Continue this flushing until the water from the lead-
away hose runs clear.
Hot Water Heater
1.
Remove water outlet hose from heater core pipe.
2.
Remove inlet hose from engine connection.
3.
Insert flushing gun and flush heater core. Care must
be taken when applying air pressure to prevent
damage to the core.
Fan Belt
Adjustment
1.
Loosen bolts at Delcotron slotted bracket.
2.
Pull Delcotron away from engine until desired ten-
sion reading is obtained with a strand tension gauge.
Refer to Section 6, "Engine Tune-Up".
3.
Tighten all Delcotron bolts securely.
Thermostat
The thermostat consists of a restriction valve actuated
by a thermostatic element. This is mounted in the hous-
ing at the cylinder head water outlet above the water
pump,
thermostats are designed to open and close at
predetermined temperatures and if not operating properly
should be removed and tested as follows.
Replacement
1.
Remove radiator to water outlet hose.
2.
Remove thermostat housing bolts and remove water
outlet and gasket from thermostat housing (fig. 2).
3.
Inspect thermostat valve to make sure it is in good
condition.
4.
Place thermostat in hot water 25° above the temper-
ature stamped on the thermostat valve.
5. Submerge the valve completely and agitate the water
thoroughly. Under this condition the valve should
open fully.
6. Remove the thermostat and place in water 10° below
temperature indicated on the valve.
7. With valve completely submerged and water agitated
thoroughly, the valve should close completely.
8. If thermostat checks satisfactorily, re-install, using
a new housing gasket.
9. Refill cooling system.
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-3
Fig.
2— Replacing Thermostat
Water Pump
Removal
1.
Drain radiator and break loose the fan pulley bolts.
2.
Disconnect heater hose, lower radiator hose and
by pass hose (as required) at water pump.
3.
Loosen Delcotron and remove fan belt then remove
fan bolts, fan and pulley.
4.
Remove pump to cylinder block bolts and remove
pump from engine.
NOTE:
On in line engines, pull the pump
straight out of the block first, to avoid damage
to impeller.
Installation
1.
Install pump assembly on cylinder block and tighten
bolts securely. Use on new pump to block gasket(s).
2.
Install pump pulley and fan on pump hub and tighten
bolts securely.
NOTE:
A guide stud (5/16"-24 x 1-1/2" bolt
with the head removed) installed in one hole of
the fan hub will aid in aligning hub, pulley and
fan.
Remove stud after starting the remaining
three bolts.
3.
Connect hoses and fill cooling system.
4.
Install fan belt and adjust as previously outlined.
5. Start engine and check for leaks.
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-9
4.
Wash body with cleaning solvent and wip dry.
5. Wash filter element by sloshing up and down in
cleaning solvent.
6. Dry filter unit with an air hose or let stand until
dry.
7. Fill body of cleaner to full mark with SAE 50 engine
oil. If expected temperatures are to be consistently
below freezing, use SAE 20 engine oil.
8. Assemble filter and cover assembly to body of
cleaner.
9. Install cleaner, making sure it fits tight and is set
down securely. \
OIL
WETTED
PAPER
ELEMENT
Replacement
1.
Remove wing nut, washer and cover.
2.
Remove paper element and discard.
3.
Remove bottom section of air cleaner and gasket
on air horn of carburetor. Discard air horn gasket.
4.
Clean bottom section of air cleaner and cover pieces
thoroughly, to remove dust and grime.
NOTE:
Check bottom section of air cleaner
seal for tears or cracks.
5. Install a new gasket on carburetor air horn and set
bottom section of air cleaner on carburetor.
6. Install new paper element on bottom section of air
cleaner with either end up.
NOTE:
Plastisol seal is the same material on
both ends.
7. Install cover, washer and wing nut.
Testing (Fig. 5A)
Tool J-7825, is designed to check paper element air
cleaners to determine whether the element has ma-
terially decreased in efficiency arid should be replaced
or has only slightly increased air restriction and is
suitable for further service. In combination with a
tachometer, this instrument will quickly and accurately
determine the air cleaner element condition.
VENT HOLE
TOWARD DASH
NOTE:
t Before testing, inspect for holes or
breaks in the element, as these defects re-
quire immediate replacement. If no holes or
breaks exist, proceed as follows:
1.
Remove all hoses and plug all openings except air
cleaner inlet.
2.
Install air cleaner, using Tool J-7825 in place of the
wing nut. Screw Tool J-7825 onto the stud until it
seals tightly against the air cleaner cover. Rotate
the entire tool so that the scale can be read from
the left side of the car. Be sure the vent hole is
toward the dash.
3.
Connect a tachometer and place it so that it may be
read simultaneously with Tool J-7825.
4.
Zero oil level in the inner tube by pulling inner tube
upward until the rubber seal is above the vent hole,
then raise or lower as' required until the inner tube
oil level is exactly to the "0" mark.
5. Start engine. If engine is cold, allow to run for 2 to
3 minutes. The automatic choke must be fully open.
6. Accelerate the engine slowly until the inner tube oil
level of Tool J-7825 just reaches the 1/4 mark.
Allow engine speed to stabilize and note tachometer
(rpm) reading. Decelerate engine.
7. If the tachometer reading is at or below the follow-
ing, the oil wetted paper air cleaner element is re-
stricted beyond the allowable limit and should be
replaced. If testing indicates that the element
restriction is satisfactory at 12,000 miles, the ele-
ment need not be replaced but should be retested
every 6,000 miles thereafter until replaced.
Engine
Displacement
283 cu.
in.
327 cu.
in.
350 cu. in.
396 cu.
in.
427 cu.
in.
Horsepower
195
210
275
300
325
350
295
325
350
385
390
425
Minimum
Allowable
RPM
2300
2100
210Q
2600
2600
1550
1950
1850
1850
2140
Fig.
5A—Testing Air Cleaner
8. Remove tachometer and Tool J-7825 from vehicle
and push down inner tube until seal is below vent
hole to prevent oil loss.
Tool J-7825
FiHing
Tool
Tool J-7825 is shipped dry and must be filled with the
red gauge oil (specific gravity .826) provided.
Pull the knurled inner tube completely out of the gauge
and add oil to the reservoir until the oil level is between
CHEVROLET CHASSIS SERVICE /MANUAL

ENGINE FUEL 6M-11
dripping fuel, but a leak on the suction would not be ap-
parent except for its effect of reducing volume of fuel on
the pressure side.
1.
Tighten any loose line connections and look for bends
or kinks in lines.
2.
Disconnect fuel pipe at carburetor. Disconnect dis-
tributor to coil primary wire so that engine can be
cranked without firing. Place suitable container at
end of pipe and crank engine a few revolutions. If
little or no gasoline flows from open end of pipe then
fuel pipe is clogged or pump is inoperative. Before
removing pump disconnect fuel pipe at gas tank and
outlet pipe and blow through them with an air hose
to make sure they are clear. Reconnect pipes and
retest while cranking engine.
CAUTION: Whenever the engine is cranked re-
motely at the starter, with a special jumper
cable or other means, 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 damaged grounding circuit in the
ignition switch.
3.
If fuel flows from pump in good volume from pipe
at carburetor, check fuel delivery pressure to be
certain that pump is operating withint specified limits
as follows:
a. Attach a fuel pump pressure test gauge to dis-
connect end of pump to carburetor pipe.
b.
Run engine at approximately 450-1,000 rpm (on
gasoline in carburetor bowl) and note reading on
pressure gauge.
c. If pump is operating properly the pressure will
be within specifications and will remain constant
at speeds between 450-1,000 rpm. If pressure
is too low, too high, or varies materially at dif-
ferent speeds, the pump should be replaced.
Removal
1.
Disconnect fuel inlet and outlet pipes at fuel pump.
Fig.
2P-Installing 283, 327, 350 V8 Engine Fuel Pump
2.
Remove fuel pump mounting bolts and remove pump
and gasket.
3.
On V8 engines; if push rod is to be removed, remove
pipe plug then remove push rod (396 and 427 cu. in.
engines), remove fuel pump adapter and gasket then
remove push rod (283 and 327 cu. in. engines).
4.
If a new fuel pump is to be installed, transfer
fittings.
Installation
1.
On V8 engines; if removed, install fuel pump push
rod and pipe fitting or fuel pump adapter. Use.
gasket sealer on gasket or pipe fitting.
2.
Install fuel pump using a new gasket and tighten
securely. Use sealer on fuel pump mounting bolt
threads.
NOTE:
On V8 engines, a pair of mechanical
fingers may be used to hold fuel pump push rod
up while installing fuel pump (fig. 2P).
3.
Connect fuel pipes to pump.
4.
Start engine and check for leaks.
CHEVROLET CHASSIS SERVICE MANUAL