1973 OPEL GT-R engine

ENGINE MECHANICAL AND MOUNTS6A- 17
seating and to prevent turning.The ends of she//s
must never be tiled flush with parting surface of
crankcase or bearing cap.Crankshaft bearings are the precision type which do
not require reaming to size. Shims are not provided
for adjustment since worn bearings are readily re-
placed with new bearings of proper size. Bearings for
service replacement are furnished in standard size
and undersizes. Under no circumstances should
crankshaft bearing caps be tiIed to adjust for wear in
old bearing.After removal of oil pan, pipe and screen assembly,
perform the following removal, inspection and in-
stallation operations on each crankshaft bearing in
turn so that the crankshaft will be well supported by
the other bearings.
If crankshaft has been removed to check straightness
the following procedure is suggested. Rest crank-
shaft on “V-blocks” at number one and number live
main bearing journals. Check indicator runout at
No. 3 main bearing journal. Total indicator reading
should not exceed
.C012”.1. Since any service condition which affects the
crankshaft bearings may also affect the connecting
rod bearings, it is advisable to inspect connecting rod
bearings
first. If crankpins are worn to the extent
that crankshaft should be replaced or reground, re-
placement of crankshaft bearings only will not be
satisfactory.
If replacement of cylinder block or crankshaft is re-
quired, always check main bearing clearance with
plastic-type gauge to obtain specified limits.
2. Remove one bearing cap, then clean and inspect
lower bearing shell and the crankshaft journal. If
journal surface is scored or ridged, the crankshaft
must be replaced or reground to insure satisfactory
operation with new bearings. Slight roughness may
be polished out with tine grit polishing cloth
thoroughly wetted with engine oil, and burrs may be
honed off with a tine stone.
3. If condition of lower bearing shell and crankshaft
journal is satisfactory, check the bearing clearance
with a plastic-type gauge.
4. When checking a crankshaft bearing with plastic-
type gauging material, turn crankshaft so that oil
hole is up to avoid dripping of oil on the gauge
material. Place paper shims in lower halves of adja-
cent bearings and tighten cap bolts to take the weight
of crankshaft
off the lower shell of beating being
checked.5. If bearing clearance exceeds
.C03”, it is advisable
to install a new bearing; however, if bearing is in
good condition and is not being checked because ofbearing noise, it is not necessary to replace the bear-
ing.6. Loosen all crankshaft bearing cap bolts
l/2 turn,
and remove cap of bearing to be replaced.
7. Remove upper bearing shell by inserting Bearing
Shell Remover and Installer J-8080 in oil hole in
crankshaft, then slowly turning crankshaft so that
the tool rotates the shell out of place by pushing
against the end without the tang. See Figure
6A-27.When turning crankshaft with rear bearing cap
removed hold oil seal to prevent it from rotating out
of position in crankcase.
8. The crankshaft journal cannot be measured with
an outside micrometer when shaft is in place; how-
ever, when upper bearing shell is removed the jour-
nal may be checked for out-of-round by using a
special crankshaft caliper and inside micrometer.
Figure 6A-27 Removing and Installing Crankshaft
Bearing Upper Shell
The caliper should not be applied to journal in line
with oil hole.
If crankshaft journal is more than
.M)12” out-of-
round, the crankshaft should be replaced since the
full mileage cannot be expected from bearings used
with an excessively out-of-round crankshaft.
9. Before installation of bearing shells make sure that
crankshaft journal and the bearing seats in crankcase
and cap are thoroughly cleaned.
10. Coat inside surface of upper bearing shell with
engine oil and place shell against crankshaft journal
so that tang on shell will engage notch in crankcase
when shell is rotated into place.
11. Rotate bearing shell into place as far as possible
by hand, then insert Installer J-8080 in crankshaft oil
hole and rotate crankshaft to push shell into place.
Bearing shell should move into place with very little

6A- 18 1973 OPEL SERVICE MANUAL
pressure. If heavy pressure is required, shell was not
started squarely and will be distorted if force into place.
12. Place lower bearing shell in bearing cap, then
check clearance
with plastic-type gauge, as previ-
ously described.
13. The desired clearance with a new bearing is
.0009” to .0025”. If this clearance cannot be obtained
with a standard size bearing, insert an undersize
bearing and check again
w&h plastic-type gauge
material.
14. When the proper size bearing has been selected,
clean out all plastic gauge material, oil the lower
shell and reinstall bearing cap. Clean the bolt holes
and lube bolts, then torque cap bolts to 72 lb. ft. The
crankshaft should turn freely at flywheel rim; how-
ever, a very slight drag is permissible if an undersize
bearing is used.
15. If the thrust bearing shell is disturbed or replaced
it is necessary to line up the thrust surfaces of the
bearing shell before the cap bolts are tightened. To
do this, move the crankshaft fore and aft the limit of
its travel several times (last movement fore) with the
thrust bearing cap bolts finger tight.
16. After bearing is installed and tested, loosen all
bearing cap bolts
l/2 turn and continue with other
bearings. When bearings have been installed and
tested, tighten all bearing cap bolts to 72 lb. ft.
17. Replace rear bearing oil seals.
18. Install pipe and screen assembly and oil pan.
Installation of Rear Bearing Oil
Seals (Engine in Vehicle)
1. Remove transmission, bell housing and clutch.
Refer to appropriate section for removal procedures.
Figure 6A-28 Removing Rear Main Oil Seal
2. Remove flywheel.
3. Punch a hole into oil seal and screw in a sheet
metal screw and pull out oil seal. See Figure
6A-28.
4. To insure proper sealing, lubricate seal with a
suitable protective grease and install on taper ring
J-22928. Turn seal to ensure lip of seal is not turned
back. See Figure
6A-27.
OIL SEAL’6A-29
Figure
6A-29 Installing Oil Seal on Tool J-22928
5. Place tapered ring with oil seal on crankshaft
flange and move lip of seal
over rear of crankshaft.
Be careful not to tilt seal.
Figure 6A-30 Installing Rear Main Bearing Oil Seal
6. Drive in oil seal using Tool J-22928-2. See Figure
6A-30.
7. Install flywheel, clutch, bell housing and transmis-
.

ENGINE MECHANICAL AND MOUNTS6A- 19
sion. When replacing flywheel use new bolts and
torque to 43 lb.ft.
PISTON, RINGS AND CONNECTING RODS
Removal and Disassembly of Piston
and Rod Assemblies
1. Drain oil.
2. Remove oil pan. 3. Remove cylinder head.
4. Examine the cylinder bores above the ring travel.
If bores are worn so a ridge exists, remove the ridges
with a ridge reamer to avoid damaging rings or
cracking ring lands in pistons during removal.
5. Mark the cylinder number on all pistons, connect-
ing rods and caps. Starting at the front end of the
crankcase, the cylinders are numbered l-2-3-4,
6. Remove cap and bearing shell from number 1
connecting rod.
7. Push the piston and
rod assembly up and out of
top cylinder. Then reinstall cap and bearing shell on
rod.
0
-J-23436-4
J-23436-2+
J-6047
Figure
6A-3 1 Piston Pin Removal Tool Layout - 1 .S
Engine
8. Remove other rod and piston assemblies in the
same manner.
9. Remove compression rings and oil rings.
10. Remove piston pin in following manner:
a. Position base support J-6047 on hydraulic press.
b. Place tool J-23436-2 in base support with large
diameter bore facing upward. See Figure
6A-31.
c. Position piston and rod assembly on tool
J-
23436-2 making certain the pin is aligned on tool.
d. Position tool J-23436-4 in opposite end of piston
pin and press pin out.
Inspection of Cylinder Bores
Inspect cylinder walls for scoring, roughness, or
ridges which indicate excessive wear. Check cylinder
bores for taper and out-of-round with an accurate
cylinder gage at top, middle and bottom
ofbore, both
parallel and at right angles to the centerline of the
engine. The diameter of the cylinder bores at any
point may be measured with an inside micrometer or
by setting the cylinder gauge dial at “0” and measur-
ing across the gauge contact points with outside mi-
crometer while the gauge is at the same “0” setting.
If a cylinder bore is moderately rough or slightly
scored but is not out-of-round or tapered, it is possi-
ble to repair the bore by honing to accept a standard
service piston. If cylinder bore is very rough or deeply scored, it may be necessary to rebore the cyl-
inder to fit an oversize piston in order to insure satis-
factory results.
If a cylinder bore is tapered
.ooO5” or more, or is
out-of-round
.0005” or more, it is advisable to hone
or rebore for the smallest possible oversize piston and
rings.
Visual Inspection of Pistons, Rings, and Pins
Clean carbon from piston surfaces and under side of
piston heads. Clean carbon from ring grooves with a
suitable tool and remove any gum or varnish from
piston skirts with suitable solvent.
Carefully examine pistons for rough or scored bear-
ing surfaces, cracks in skirt, head cracked or broken
ring lands, and chipping or uneven wear which
would cause rings to seat improperly or have exces-
sive clearance in ring grooves. Damaged or faulty
pistons should be replaced.
Fitting Pistons to Cylinders
The pistons are cam ground, which means that the

ENGINE MECHANICAL AND MOUNTS6A- 21
2.. Expand a telescope gage to fit the cylinder bore at
right angles to the piston pin 2-l/2” from top. See
Figure 6A-33.cylinders, the glazed cylinder walls should be slightly
dulled without increasing the bore diameter by
means of the finest grade honing stones.
TELESCOPE GAUGE1
Figure 6A-33 Checking Cylinder Bores
TELESCOPE/GAUGE
MICROMETER
Figure
6A-34 Measuring Telescope Gage3. Measure the piston to be installed. See Figure6A-32. The piston must be measured at right angles
to the piston pin
2-l/2” below the top of piston. The
piston must be between
.C008” and .0012” smaller
than the cylinder bore.
Both block and piston must be at approximately the
same temperature when measurements are made or
expansion errors will occur. A
dif.ference of 10 de-
grees F between parts is sufficient to produce a varia-
tion of .0005”.
Fitting New Piston RingsWhen new piston rings are installed without reboringNew piston rings must be checked for clearance in
piston grooves and for gap in cylinder bores; how-
ever, the flexible oil rings are not checked for gap.
The cylinder bores and piston grooves must be clean,
dry, and free of carbon and burrs.
To check the end gap of compression rings, place the
ring in the cylinder in which it will be used and
square it in the bore by tapping with the lower end
of a piston. Measure the gap with feeler gages.
Piston ring end gap should be
,014” - ,022” (top) and
,014” - ,022” (2nd) and the oil ring end gap should
be
.015” - ,055”.
If gap is less than specified, file the ends of rings
carefully with a smooth tile to obtain proper gap.
Install piston rings as follows:
1. Upper ring is chrome plated and can be installed
either way up. Number two (2) ring has to be in-
stalled with the marking “top” up. Oil ring can be
installed either way
up. See Figure 6A-35.
1. PISTON
2. NO.
I COMPRESSION RING - INSTALLED
WITH EITHER SIDE UP.
3. NO. 2 COMPRESSION RING - INSTALLED
WITH “TOP” MARKING TOWARDS THE TOP.
4. UPPER AND LOWER STEEL BAND RING
-
INSTALLED WITH EITHER SIDE UP.5. INTERMEDIATED RING
- INSTALLED WITH
EITHER SIDE UP.
6A-35
Figure 6A.35 Arrangement of Piston Rings2. Install piston rings so gaps are positioned as shown
in Figure 6A-36.

6A- 221973 OPEL SERVICE MANUALI. NO. I COMPRESSION - GAP IN FRONT
2. NO. 2 COMPRESSION - GAP IN REAR
3. UPPER STEEL BAND -
I - 2 IN.TOWARDS
THE LEFT OF INTERMEDIATE RING GAP
4. INTERMEDIATE RING - GAP IN FRONT
5. LOWER STEEL BAND -
I - 2 IN.TOWARDS
THE RIGHT OF INTERMEDIATE RING GAP.‘A” VERTICAL LINE FOR PISTON AND RINGS, FRONT
6A-36Figure 6A-36 Location of Piston Ring Gaps
With rings installed on piston, check clearance in
grooves by inserting feeler gages between each ring
and its Iower land. Any wear that occurs forms a
step at inner portion of the lower land. If the piston
grooves have worn to the extent that relatively high
steps exist on the lower lands, the piston should be
replaced since steps will interfere with the operation
of new rings causing ring clearances to become exces-
sive. Piston rings are not furnished in oversize widths
to compensate for ring groove wear.
When fitting new rings to new pistons, the side clear-
ance of the compression rings should be X024”
-
.1X34” (top) and .0013” - .OO24” (2nd), and the oil
ring clearance should be
.OO13” - .0024”.
Assembly of Piston and Connecting Rod
NOTE:Connecting rods may be out of alignment
due to shipping or
hand/i& Always check a new
rod before installing piston and pin.Inspect piston pin bores and piston pins for wear.
Piston pin bores and piston pins must be free of
varnish or scuffing when being measured. The piston
pin should be measured with a niicrometer and the
piston pin bore should be measured with a dial bore
gage or an inside micrometer. If clearance is in excess
of the
,001” wear limit, the piston and piston pin
assembly should be replaced.
1. Lubricate piston pin holes in piston and connect-
ing rod to facilitate installation of pin.
2. Install pin in following manner:
a. Position base support J-6047 on hydraulic press.b. Place tool J-23436-l in support J-6047 with small
diameter bore facing upward.
c. Place small end of tool J-23436-3 in bore of tool
J-23436- 1.d. Position piston, rod, and pin guide J-23436-3.
e. Line up pin on piston, and using tool J-23436-4
press pin into piston. See Figure 6A-37.
Ii-J-23436-4
J-23436-3--,J-23436-1
--cJ-6047
Figure 6A-37 Piston Pin Installation Tool Layout
- 1.9
Engine
3. Remove installer from connecting rod and piston
assembly and check piston for freedom of movement
on piston pin.
4. Make sure cylinder bores, pistons, connecting rod
bearings and crankshaft journals are absolutely
clean, then coat all bearing surfaces with engine oil.
5. Before installation of a piston and rod assembly in
its bore, position the crankpin straight down.
6. Remove connecting rod cap.
7. Make sure the gap in the oil ring rails and the gaps
of the compression rings are positioned correctly.
8. Lubricate the piston and rings and install in bore

ENGINE MECHANICAL AND MOUNTS6A- 231. NOTCH IN PISTON HEAD
POINTING TOWARD THE FRONT
2. OIL HOLE IN CONNECTING ROD
POINTING TOWARD THE RIGHT
(MANIFOLD SIDE)
3. NOTCH IN CONNECTING ROD
CAP POINTING TOWARD THE
REAR6A-36
Figure
6A-39 Piston and Rod Assemblyby oompressing the rings with a “wrap around” com-
pressor.9. Select a new connecting rod bearing, if necessary.
Otherwise install cap with bearing lower shell on rod
and tighten bolt nuts to 36
lb.ft. torque.
10. Install all other piston and rod assemblies in same
manner. When piston and rod assemblies are prop
erly installed, the oil spurt holes in the connecting
rods will be facing right.
11. Check end clearance between connecting rods in
each crankpin using feeler gages. Clearance should
be between
.0043” and .0095”.
12. Install cylinder head. Torque 10 cylinder head
bolts to 72 lb.ft (cold), and 2 cylinder head to timing
chain cover bolts to 17
lb.ft.13. Install new oil pan gasket by first installing flange
gasket with tabs in slots in rear main bearing cap and
engine front cover. Then install rubber strips in
grooves in rear main bearing cap and engine front
cover. Install oil pan, torquing bolts to 5 lb.ft.
14. Install (Opel
1900 and Manta) front suspension
assembly. (GT) Install engine suspension cross mem-
ber.After installation of new pistons and rings, care
should be used in starting the engine and in running
it for the first hour. Avoid high speeds until the parts
have had a reasonable amount of break-in so that
scuffling will not occur.
TIMING CHAIN COVER AND TIMING CHAIN
Timing Chain Cover Removal
1, Support engine in vehicle as outlined under Engine
Oil Pan Removal and Installation.
2. Remove radiator and shroud assembly
3. Remove cylinder head.
4. Remove alternator belt and remove alternator
mounting bracket.
5. Remove fuel pump
6. Remove ignition distributor.
7. Remove chain tensioner assembly out of timing
cover.8. Remove crankshaft pulley bolt and remove pulley.
9. Remove water pump assembly.
10. Remove oil pan
11. Remove timing chain cover bolts. One bolt is
covered by the water pump. See Figure 6A-39.
12. Pull off sprockets with chain. Put a paint mark
Figure 6A-39 Bolt Behind Water Pump

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.

ENGINE MECHANICAL AND MOUNTS6A- 251, CAMSHAFT SPROCKET
2. CAMSHAFT SPROCKET SUPPORT
3. LONG DAMPER BLOCK
4. CRANKSHAFT SPROCKET
5. CHAIN AND DAMPER BLOCK
IN PARALLEL
6. CRANKSHAFT KEY
7. PAINT MARK ON FRONT
8. TIMING CHAIN
9. MARK ON CAMSHAFT
SPROCKET SUPPORT
IO. MARK ON CAMSHAFT
SPROCKET
6A-41Figure 6A-4 1 Valve Timing Marks
Removal4. Lubricate new oil seal and place on installer
J-
22924.1. Remove cylinder head.
5. Place installer J-22924 on crankshaft. Using
crankshaft bolt and washer install seal into cover. See
Figure 6A-42.2. Loosen self-locking rocker arm nuts and swing
rocker arms off valve lifters.
6. Install crankshaft pulley, bolt and washer. Torque
bolt to 72
Ib.ft.3. Remove valve lifter. Place lifters in a suitable hold-
ing fixture so that they may be reinstalled in original
position.
7. Install belts and torque to proper tension 45
lb.ft.4. Remove cover from access hole on left side andFigure 6A-42 Installing Timing Chain Cover Oil Seal
Replacing Distributor Drive Gear
On Crankshaft1. Remove fan belt.
2. Remove fuel pump. Plug end of fuel line with a
suitable stop.
3. Remove spark plug wires, distributor hold down
clamp. Remove distributor.
4. Turn crankshaft so key is on top.
5. Pry oil seal out of timing chain cover.
6. Insert a screwdriver through opening for fuel
pump and push out distributor drive gear, which has
a push tit on crankshaft, through oil seal seat in
timing cover.
7. Install new gear. Be sure key tits in
keyway. When
installing components, use new gaskets as required.
8. Install new oil seal.
9. Connect parts removed in steps 1 thru 3.
CAMSHAFT