1973 OPEL GT-R service

6A- 24 1973 OPEL SERVICE: MANUAL
on front side of timing chain to permit reinstallation
in original position.
Timing Chain Cover and Timing
Chain installation
Reinstall timing chain cover by reversing removal
procedures, pay particular attention to the following
points.
1. Clean all parts, check for wear and replace as
required. The Parts Department supplies either the two sprockets complete with chain or the chain
alone. It is not permissible to replace sprockets alone.
The chain tensioner is, with the, exception of the
tensioner body, only available as a complete unit.
2. Turn crankshaft so that key for sprocket is on top
and vertical. Assemble chain’, with camshaft
sprocket, then put chain on crankshaft sprocket al-
ready installed. Be sure paint dot
on chain is in front
so that chain moves in same direction as prior to
disassembly.
3. Make sure camshaft sprocket mark is in alignment
with mark on support and chain in parallel with
damper block.
4. To install new timing case oil seal, drive out oil
seal from the rear using a drift. Coat circumference
of oil seal sparingly with suitable sealer and press seal
in, using tool J-22924. Take care not to damage tim-
ing case. See Figure
6A-40. 5. Inspect chain tensioner for proper operation and
reusability.
6. Install timing case rubber gaskets to cylinder
block. Stick on with grease as necessary. Gaskets will
somewhat overlap with oil pan gasket.
7. Position timing cover onto guide pin in upper left
corner of cylinder block and insert centering bolt
through timing chain cover into lower right corner
of cylinder block. See Figure
6A-40A. No sealing is
required.
SA-40.4
Figure 6A-40A Installing Timing Chain Cover
INSTALLER
Figure 6A-40 Installing Timing Cover Oil Seal onProtector
It is not necessary to use crankshaft bolt to install
seal when cover is off engine. 8. Install cylinder head
After sprocket has been attached to camshaft, re-
check alignment
LO see that chain has not slipped. At
this time both No.
1 and No. 4 pistons will be at TDC
position. No. 4 piston will be in tiring position and
No. 1 piston up on exhaust stroke. To time engine to
fire on No. 1 cylinder, rotate crankshaft 360 degrees.
This will position the timing mark 180 degrees from
original alignment of camshaft sprocket and support
bracket, and will completely close No. 1 intake and
exhaust valves. Also, the timing mark on the fly-
wheel
(ball) and cylinder block (pointer) will coin-
cide. See Figure
6A-41.
Replacing Timing Cover Oil Seal
(Engine Installed)
1. Remove fan belts.
2. Remove crankshaft pulley bolt and remove pulley. 3. Insert screwdriver behind seal and rest screw-
driver on crankshaft pin. Pry out oil seal.

6A- 261973 OPEL SERVICE MANUAL
rear of cylinder head. Remove camshaft toward
front, supporting camshaft with one hand through
access hole and taking care not to damage bearing
surfaces. See Figure 6A-43.12345 6
I. OLD PRESSURE
4. COVER GASKET
RELIEF
~~- \SSEMBLY5. COVER 8 VALVE
ASSEMBLYVALVE I
2. TIMING CASE
6. COVER ATTACHING
3. OIL PUMP GEARS
SCREWS
123” 45Figure 6A-44 Oil Pump Components
1.CAMSHAFT
2. FRONT ACCESS HOLE
3. LATERAL ACCESS HOLE
4. CYLINDER HEAD
5. REAR ACCESS HOLEISA-43
Figure 6A-43 Removing Camshaft
Installation
1. Liberally lubricate camshaft journals and install
camshaft from front into cylinder head. Support
shaft through access hole in left side of head to pre-
vent damaging bearings.
2. Reinstall valve lifters, rocker arms and self- lock-
ing rocker arm nuts.
3. Install rear and side access plates.
4. Reinstall cylinder head.
OIL PUMP COVER AND GEARSRemoval and Installation of Oil Pump
Cover and Gears
1. Remove screws attaching oil pump cover assembly
to timing chain cover. Remove cover assembly and
slide out oil pump gears. See Figure 6A-44.
2. Wash off gears and inspect for wear, scoring, etc.
Replace any gears not found serviceable. Discard
pump covers scored by gear action. If pump housing
or distributor drive shaft bushing are worn (this is
only possible after a long service life), the timing case
together with all exchangeable pump parts have to be
discarded.In isolated cases, timing cases are installed in pro-
duction having
.008 in. oversize bores for pump gears
and shafts. Oversize bores may exist either for one or
both gears; these timing cases are identified by the
number “0.2” stamped into pump flange on left and-
/or right-hand side. Oversize replacement gears
should be selected according to Part Catalog specifi-
cations.
3. Liberally lubricate spindles and gear teeth and use
new cover gasket. Install oil pump cover.
If new gears are installed, their end clearance in a dry
pump housing should be checked with a straight
edge and a feeler gauge. The gears must not protrude
more than X04 in. over pump housing. See Figure6A-45.
FEELER
AUGESTRAIGHTIEDGE
Figure 6A-45 Checking Oil Pump Gear End Clearance

6A- 28 1973 OPEL SERVICE MANUAL
Part
ConnectingRod Bolts..........................................................
Crankshaft Main Bearing Bolts
..........................................
FlywheeltoCrankshaft AttachingBolts..........................
Cylinder Head Attaching Bolts....Cold 72 -Warm 58
Camshaft Sprocket Attaching Bolts................................
Generator Bracket to Cylinder Block
Attaching Bolts ..................................................................
Generator Bracket to Timing Case Attaching Bolts
....
Crankshaft Pulley Attaching Bolts ....................................
Rocker Arm Stud in Cylinder Head ..................................
Spark Plugs ........................................................................\
....
Clutch Housing to Cylinder Block Attaching Bolts
......
Timing Case to Cylinder Block AttachingBolts ............
Water Pump to Timing Case AttachingBolts................
Engine Support to Cylinder Block Attaching Bolts
......
Rear Engine Suspension to Transmission Rear Bearing Retainer Bolts ....................................................
Transmission to Clutch Housing Attaching Bolts
........
Starter to ClutchHousing AttachingBolts....................
Support to Starter Attaching Nut
....................................
Intake and Exhaust Manifold to Cylinder Head Attaching Bolts ..................................................................
Unless Otherwise Noted:
10
@i Bolt (15 MM Hall.....................................................................- -
36
72
43
18
;i
72
29
30
36
14
11
40
22
29
40
4
33 ............30
8 MM Bolt (13 MM Head)........................................................................\
........................................................................\
........................................15
6 MM Bolt (10 MM Head)
30 Lb.In.
Torque
Lb.Ft.
GENERAL SPECIFICATIONS
Type - No. of Cylinders
Valve Arrangement........................................................................\
........................................................................\
......................................................I;nlinzai
Bore and Stroke Piston Displacement Cu. In.
........
3.66 x1:;:;
Compression Ratio......................................................................................\
........................................................................\
........................................................................\
........................................
\fô\
²…..............7.6:1Octane Requirement........................................................................\
..........
Firing Order........................................................................\
........................
Regular - Lo;-?::
....................Cylinder Block Material....... ...............................................................................\
..............................................Cast Iron
Crankshaft Bearings Number and Type 5 Removable Steel Backed
In-Metal Babbitts
Bearing Which Takes End Thrust
........................................................................\
...................5
Connecting Rod Bearing Material
........................................................................\
..................
Steel Backed Tri-Metal Babbttts
Piston Material and Surface Aluminum Alloy, Lead Coated
Piston Pin Offset
........................................................................\
............,031 In. to the RightCompression Rings Material and Surface Treatment
No.
1....... ........... ............... ........ ............. ................Chrome-plated, Cast Iron
- Rectangular
No. 2
........................................................................\
..............................Cast Iron - Tapered
Oil Ring
........................................................................\
..................Chrome-plated, Cast Ir?n
Location of All Piston Rings
........................................................................\
Above Ptston Pm
Camshaft Material
........................................................................\
....................Alloy Cast Iron
Camshaft Drive........................................................................\
........................................Chajn
Number and Type of Camshaft Bearings 4 Steel-Backed Babbttt
Valve Lifter Type
..............................................................................................\
..........................................~..........Hydraulic
Oiling System Tvoe........................................................................\
Circulatmg High Pressure
Oil
&ppiied to: - .
Bearing Surfaces, Crankshaft, Camshaft and Connecting Rods............................Pressure
Piston, Pins
........................................................................\
............................................Vapor
Cvlinder Walls........................................................................\
..........................Nozzle Spray
Rocker Arms _,,,..,,....,._..___.,,..,,..............,,,,...,.......,..,,,.,.,,.....\
....,,...,.,.................~...... Pressure
Oil Reservoir Capacity
- Quarts .,,,...,,__.,,..,..,,..,...,..,,,...,,..............,,,... 3 l/4 With Dry Fdter
Oil Filter
- Type ,,....,__.,,...,....,....,,..,,,..,,...........,........................\
............ Throw Away Element

GA. xl1973 OPEL SERVICE MANUAL
Valve Seat and Correction Angle in Cylinder Head
Intake
Valve Seat Angle ..,._,..__....,,..,,,..,.,.,.,..............,............................................................... 45”Outer Correction
.,,,.,,._.,._..___,,,.,,,,,.......,,.,..,...,,..,..,,..,,..,,,.............................................. 30”
Exhaust
Valve Seat Angle
,,,.,,.__,.__..___.,..,,..,...,,....,..,..,..,,..,..,...,..,,,...,,......................................... 45”
Outer Correction
.,,..,,...,._.,.__....,,,.....,,,........................................................................... 30”
Valve Face Angle
,,..,,,..,.__..__.._..,,,..,,...,,......,.,..,..,..,,.,,,..,..,,,..,,,..,,,...,,................................ 44”Valve Seat Width in Cylinder Head
Intake
. . . . . . . . . . .._..._._.................,,..,.....,,..,............,...,..,,,..,,..,,...,,...,,,..,..................049-,059 In.
Exhaust
.,..,,,..,,.___..,,..,,...,..,,,..,,...,,...,,...............,,..,,..........,,....,,...,..................... .063-,073 In.Valve Head Contact Area
,,..,,,..,,___.__.,,..,,..,.,,..........,...,,..,,............,,,...,....... Aim at Centricity
Valve Clearance at 176°F. Coolant and 140°F. to 176”
Oil Temperature
Intake and Exhaust
_.,,..,,,,,,..,,....,...,,,.,.,,,.,..........................,,,..,,,,.... Zero Plus One Turn
Cranking MechanismMax. Permissible Out-of-Roundness of Connecting Rod Bearing
Journals
.....................................................................................................................OC02 In.
Max. Permissible Taper of Connecting Rod and Crankshaft Bearing
Journals
.....................................................................................................................ooO4 In.
Max. Permissible Radial Runout of Center Main Bearing
JournalsWhenSupportedinEndBearings
...........................................................0012In.Max. Permissible UnparalYelism of Connecting Rod Bearing
Journals When Crankshaft is Placed in V-Blocks so That
Main Bearing Journals Next to Each Other Are Supported
................................0005 In.
Max. Permissible Runout of Crankshaft to Flywheel
Contact Area
...........................................................................................................0008 In.
Crankshaft End Play
.........................................................................................GOl7-.CO61 In.
MainBearingClearance
.....................................................................................ooO9-.@I25In.Connecting Rod Bearing Clearance
.................................................................ooO6-.0025 In.
Connecting RodEnd PlayonBearing Journal
...............................................0043-.0095In.Connecting Rod Bearing Length
.......................................................................7785-.7992 In.
CrankshaftThrustBearingLength
..............................................................................1.08In.
Valve MechanismCamshaft Bearing Clearance
.................................................................................OOl-,003 In.
Camshaft End Play
...............................................................................................004-038 In.
Max. Permissible Radial Runout of Camshaft Center Bearing
- Camshaft Supported in Outer Bearings................................................................,001 In.
ValveLifter Clearance in Cylinder HeadBore
...............................................0003-.OOl3In.
Engine Lubricating SystemOil Pump Gear Backlash
......................................................................................0%.008 In.
Oil Pump Gear End Play in Housing
........................................Gears Protruding Over Edge
of Housing: Not More Than
,004 In.
Clearance of Spindle in Bore of Oil Pump Driven
Gear
...............................................................................................................OCO3-.0015 In.
Clearance Between Oil Pump Drive Gear and
Bushing
.........................................................................................................00035-.OOl5 In.
Oil Pump Relief Valve Spring Pressure at a Spring Length
of
.8 In..................................................................................................................44-.66 Lbs.

66.321973 OPEL SERVICE MANUAL
COOLING SYSTEM
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Cooling System and Water Pump
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Checking and Filling Cooling System
. . . . . . . . . . . . . . . . . . . . . . . .Draining
andFlushingCoolingSystem. . . . . . . . . . . . . . . . . . . . . .Conditioning the Cooling System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Using and Testing Anti-Freeze Solutions
. . . . . . . . . . . . . . . . . .Fan Belt Adjustment or Replacement
. . . . . . . . . . . . . . . . . . . . . . . .Radiator Thermostat Inspection and Test
. . . . . . . . . . . . . . . .MAJOR REPAIR:
Water Pump Removal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Radiator
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Cooling System Capacities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.
68-32
6B-32
68-32
68-33
68-33
68-33
68-33
68-34
68-34
6B-35
DESCRIPTION AND OPERATION
COOLING SYSTEM AND WATER PUMPThe coiling system is of the conventional pressurized
type. A centrifugal pump arranged in timing case
serves to circulate the coolant.
When the thermostat is closed, the coolant will re-
turn to the pump via a by-pass for swift and uniform
warming up of the engine the coolant circulates
through the radiator, only when the engine has
reached normal operating temperature.
The heater system branches off the cooling system
ahead of thermostat in flow direction so that the
heater is in operation before engine has reached full
operating temperature.
MAINTENANCE AND ADJUSTMENTS
Checking and Filling Cooling SystemThe coolant level should be checked only when the
engine is cold and only enough coolant should be
added to bring the level halfway between core andtank top. It is unnecessary and undesirable to remove
the radiator cap and check the coolant level each
time the car stops at a filling station for gasoline or
oil, since the engine is usually hot at such times.
WARNING: Never remove the radiator cap quickly
when engine is HOT Sudden release of cooling
sys-
tern pressure may cause the coolant to boil and some
of it may be ejected from the radiator
filler neck,
resulting in
inl’ury to persons or damage to the car
finish.If it is necessary at any time to remove the radiator
cap when engine is hot, rotate the cap counterclock-
wise until first stop is reached. Leave cap in this
position until all pressure in cooling system has been
released, then turn cap past the first stop and remove
it.
Draining and Flushing
Cooling SystemThe cooling system should be completely drained
and the recommended coolant installed every two (2)
years.To drain the cooling system, remove radiator cap,
remove lower radiator hose from the lower tank and

6B- 341973 OPEL SERVICE MANUAL
test by partially draining the cooling system and dis-
connecting the water outlet housing from the ther-
mostat housing which is mounted on the right front
side of cylinder head.
The standard thermostat valve should start to open
at 189 degrees F and fully open at approximately 212
degrees F. If thermostat does not operate at specified
temperatures, it should be replaced as it cannot be
repaired.MAJOR REPAIR
WATER PUMP REPAIRSThe water pump bearing outer race is shrunk fit into
the water pump cover. For this reason the cover,
shaft bearing, and hub are not repairable.
Water Pump RemovalOpel radiators do not have a drain plug. Drain radia-
tor by first, loosening radiator cap, then remove
lower hose from lower radiator tank.
1. Drain coolant into a clean container. Remove
radiator and shroud.
2. Remove fan belt.
3. Remove fan blade and pulley on water pump shaft.
4. Disconnect inlet hose and heater hose from water
pump. Remove bolts, pump assembly and gasket
from timing chain cover.
5. Check pump shaft bearing for end play or rough-
ness in operation. If bearings are not in serviceable
condition, the assembly must be replaced.
Water Pump Installation1. Make sure the gasket surfaces on pump and timing
chain covers are clean. Install pump assembly with
new gasket. Bolts must be tightened uniformly.
Torque to 11 lb. ft.
2. Install radiator and shroud. Connect radiator hose
to pump inlet and heater hose to nipple.
3. Install fan pulley and fan blade, tighten attaching
bolts securely. Install belts and adjust for proper
tension.4. Fill cooling system and check
,for leaks at pump
and hose joints.
RADIATOR REMOVAL AND INSTALLATION
RemovalI. Loosen radiator cap, then remove lower radiator
hose and drain radiator coolant into suitable con-
tainer.
2. On vehicles with automatic transmission, unscrew
oil lines from connectors on lower radiator tank and
plug lines. On GT models with automatic transmis-
sion the lines have to be disconnected at the coupling
before removing from the tank. It is essential that no
dirt enters the oil lines. When unscrewing oil lines,
hold connectors on lower radiator tank with pliers to
avoid leakages. Ensure that no dirt enters oil cooler.
3. Remove lower attaching nut and slide radiator
upward and out of engine compartment.
Installation1. Install radiat,or into engine compartment and se-
cure lower attaching nut.
2. On vehicles with automatic transmissions, fasten
oil cooler lines to lower radiator tank. It is essential
that no dirt enters the oil lines. When tightening oil
lines, hold connectors on lower radiator tank with
pliers to avoid leakages. Ensure that no dirt enters oil
cooler. Torque to 1 I-15
lbs.ft.3. Install lower radiator hose and add collected coo-
lant.
All Opels are provided with a radiator initial fill of
an antifreeze solution containing corrosion inhibitor.
The antifreeze has either a glycol or glycerin base
and protects the engine against freezing, down to
minus 22 degrees F. (minus 30 degrees C.). Before
the start of the cold season, coolant must be checked
with a hydrometer and if necessary, brought to the
necessary specific gravity by adding anti-freeze with
a glycol or glycerin base. As the specific gravities of
all anti- freeze solutions having a glycol or glycerin
base are practically the same, the hydrometer can be
used for all these types. Because of the tolerances of
the hydrometer, or slight differences in specific
gravity, variations of plus or minus 5 degrees can be
expected. Coolant must be checked at a temperature
of plus 68 degrees F. (plus 20 degrees C.)

6C- 361973 OPEL SERVICE MANUAL
FUEL SYSTEM
ALL MODELS
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Fuel Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .Evaporation Control System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS:
(Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Cleaning Fuel Pump Strainer.,....................................
*.Evaporation Control System
. . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Fuel Tank
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Fuel Lines and Fuel Tank Gauge Units
. . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Fuel System Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.6C-366C-376C-376C-386C-396C-416C-41
DESCRIPTION AND OPERATION
FUEL PUMPThe 1.9 liter engine uses a push rod type fuel pump.
The push rod is actuated by an eccentric on the
distributor shaft. The push rod is held in contact
with the eccentric at all times by a push rod spring.
Each time the push rod is on the high part of the
eccentric, the lighter diaphragm spring will push the
diaphragm to replace any fuel used in the carburetor.
The diaphragm seldom operates through a full
stroke; under normal driving conditions, the dia-
phragm moves only a few tenths of an inch.
Fuel pump pressure is determined by the compres-
sion of the diaphragm spring. Low pressure or pres-
sure leak- down generally indicates a leaky
diaphragm or check valves.
Two holes in the lower part of the fuel pump serve
to ventilate the space below the diaphragm and to
drain any fuel which may have entered. If any fuel
comes from these holes, this indicates a defective
diaphragm.When replacing the fuel pump, make sure the asbe-
stos spacer is in place with a gasket on each side. See
Figure 6C- 1. Because of the location of the fuel pump
eccentric on the distributor shaft, the fuel pump
Figure
6C-1 Installing Push Rod Type Fuel Pump

6C- 381973 OPEL SERVICE MANUALCAUTION:Because the fuel pump is below fuel tank
level, fuel
will drain from the tank. when the supply
hne is disconnected from the fuel pump.1. Pull fuel supply line and rubber connector from
fuel pump. Plug rubber connector to prevent fuel
loss.2. Remove fuel pump cap, gasket and plastic
strainer.
3. Cover center opening in sediment bowl with finger
and blow out sediment bowl with compressed air.
4. Wash plastic strainer in solvent; if strainer does
not clean-up or is damaged, replace strainer.
5. Install clean parts, noting the following:
(a) Strainer must be properly seated with projections
facing upward.(b) A new cap gasket must be positioned over
strainer.
(c) Sealing ring must be in place on cap retaining
screw.6. Reconnect fuel supply line. Start engine and check
for leaks.
EVAPORATION CONTROL SYSTEMProper performance of the system requires the use of
a non-vented fuel tank cap, hose connections be leak-
free, and all hoses routed correctly to avoid a
pinched or blocked line.
Maintenance requirements demand only that the ac-
cumulator purge air tilter, an oiled foam filter assem-
bled in the bottom of the canister, be replaced at
12,CKO mile intervals. Under extremely dusty condi-
tions, more frequent attention may be required.
Figure
W-4 Exploded View of Opel 1900 and Manta Fuel Tank