Page 111
214-10
Cylinder Head and Valve Mechanism
Fig. 20. Valve stem oil seals being removed using special pliers.
Fig. 21. Black camshaft bearing cap bolts are specially drilled and
must always be installed on the spark plug side of the cap.
stem oil seals, tapping them in using an appropriate drift and a
plastic hammer. Be sure to install the lower valve spring seat
before installing the valve stem oil seals.
CAUTION
When installing the camshafts, place the cylinder head on
wooden blocks to prevent damaging the valves as the camshaft bearing caps are tightened down. Tighten all caps evenly in three or four stages.
Always refit the cam followers in their original positions.
Make sure the numbers on the camshaft bearing caps align
with their numbers on the cylinder head, if applicable. Install
the black camshaft bearing cap bolts on the spark plug side of
the cap.
CAUTION
The black camshaft bearing cap bolts must always be fitted to
the spark plug side of the bearing cap. These bolts are drilled
to provide oil passages to the hydraulic cam followers. See
Fig. 21.
Fig. 22. Oil spray bar fittings correctly installed for proper lubrication
to the camshafts and cam followers.
Tightening Torques
NOTE
Bearing caps marked with numbers 1 through 5 are used on
the intake camshaft and 6 through 10 are used on the exhaust
camshaft.
If applicable, replace any worn or faulty O-rings for the oil
spray bar fittings. To ensure proper lubrication, make sure the
holes in the spray bars align with the holes in the fittings. See
Fig. 22.
VALVE MECHANISM
• camshaft bearing caps
to cylinder head
15 Nm (11 ft-Ib)
28 Nm (21 ft-Ib)
• spark plugs to cylinder head
63 Nm (46 ft-Ib)
• camshaft sprocket to camshaft
• intake manifold to cylinder head
18 Nm (13 ft-Ib)
• exhaust manifold to cylinder head
turbo models
25 Nm (18 ft-Ib)
normally-aspirated models
20 Nm (15 ft-Ib)
• timing chain cover
to cylinder head
20 Nm (15 ft-Ib)
15 Nm (11 ft-Ib)
• valve cover to cylinder head
• ignition distributor to cylinder head .. 20 Nm (15 ft-Ib)
Page 112
Cylinder Head and Valve Mechanism
214-11
VALVE MECHANISM RECONDITIONING
For anyone with the proper equipment and basic experience in cylinder head reconditioning, this section provides the
necessary specifications and special reconditioning information.
Cylinder Head Assembly
The disassembled cylinder head should be carefully inspected for warpage, cracks, and wear. Check the valve
guides and valve seats for wear as described below under
Valve Guides and Valves and Valve Seats.
Always decarbonize and clean the head before inspecting
it. A high quality straight edge can be used to check for
warpage. Visually inspect the cylinder head for cracks. If a
cracked cylinder head is suspected and no cracks are detected through the visual inspection, have the head further tested
for cracks by an authorized Saab dealer or a qualified machine shop. A cracked cylinder head should be replaced.
A warped cylinder head can be machined provided the minimum cylinder head height is not exceeded. If further machining is required, the head should be replaced. Removing more
than this amount will reduce the size of the combustion chamber and adversely affect engine performance.
CAUTION
If the cylinder head has been machined, make sure all sharp
edges and burrs are removed from the combustion chamber.
Lightly smooth the edges all around the combustion chamber
and remove any imperfections.
Always check the total height of the cylinder head prior to
machining. See Fig. 23. A maximum amount of 0.4 mm (0.016
in.) can be removed from a new cylinder head. If the cylinder
head has been previously machined, it probably cannot be
machined again. Cylinder head dimensions and minimum resurfacing height specifications are listed below.
Cylinder Head Height (dimension A)
140.5±0.1 mm (5.531 ±0.004 in.)
140.1 ±0.1 mm (5.516±0.004 in.)
0.4 mm (0.0016 in.)
• new
• after machining
• machining limit
Check the camshaft followers and the follower bores for
wear. Replace the cam followers or the cylinder head if any
signs of wear are visible or if any part does not meet the specifications listed below.
Fig. 23. Front view of cylinder head showing minimum resurfacing dimension (A). Measure between valve cover gasket surface
and cylinder head gasket surface.
Cam followers
• diameter
• height.
• bore in cylinder head
32.96-32.98 mm
(1.2976-1.2984 in.)
26 mm
(1.02 in.)
33.000-33.016 mm
(1.2992-1.2998 in.)
Camshafts
Camshaft wear is usually caused by insufficient lubrication.
Engine oil dilution, extended oil drain intervals, or high mileage are all additional causes of camshaft wear. Checking the
camshaft for wear and runout requires precision measuring
equipment.
Visually inspect the camshaft lobes and journals for wear.
Lightly lubricate the camshafts and place them in the cylinder
head. Install and tighten the bearing caps. Check that the
camshaft turns smoothly. Using a feeler gauge, check the
camshaft axial play (end float) between the camshaft flange
and the thrust surface on the front of the cylinder head.
Camshaft
• axial play (end float)
maximum permissible
0.08 to 0.35 mm
(0.0031 to 0.0138 in.)
• camshaft bearing diameter ..... 28.922-28.935 mm
(1.1387-1.1392 in.)
VALVE MECHANISM RECONDITlONING
Page 113
214-12
Cylinder Head and Valve Mechanism
Valve Guides
I
Valve guide specifications are listed below. Check valve
guide wear with a new valve as shown in Fig. 24. inspect the
valve seats to ensure that the cylinder head can be reconditioned before installing new valve guides.
I
Valve Guides
• length
• outside diameter
• bore for valve guide
in cylinder head
.49.00 mm
(1.929 in.)
12.039-12.050 mm
(0.4740-0.4744 in.)
12.000-12.018 mm
(0.4724-0.4731 in.)
J
i
Removal
87025
" - - - - - - - - _ .
Fig. 25. Saab special tools for removing and installing valve guides.
Valve guide removal/installation special tools
• jack screw (1)
tool no. 83 90 494
• pull rod (2)
tool no. 83 93 811
• spacer sleeve (3)
tool no. 83 93 829
tool no. 8393837
• stop (4)
• special nut(5)
tool no. 83 93 845
• mandrel (6)
tool no. 83 90379
To replace valve guides
1. Flush the cylinder head with hot water.
Fig. 24. Valve guide wear being checked. Raise valve 3 mm (0.12
in) from its seat and rock the valve head to check for play.
(Saab 8-valve cylinder head shown.)
Valve guide wear
(clearance between valve guide and valve stem)
• maximum permissible
0.5 mm (0.02 in.)
CAUTION
Always heat the head with hot water prior to removing and installing the valve guides. Failure to the heat the head may result in damage to the cylinder head casting.
2. Working from the camshaft side of the cylinder head,
insert the special tools. See Fig. 26 and Fig. 27. Withdraw the valve guide by turning the jack screw.
Saab special tools should be used to replace worn valve
guides. See Fig. 25. Always finish replacement valve guides
using a 7.0 mm (H7) reamer.
NOTE
The Saab special tools are recommended to replace the valve
guides, although conventional methods can also be used.
Fig. 26. Valve guide being removed uSing speCial tools.
VALVE MECHANISM RECONDITIONING
Page 114
Cylinder Head and Valve Mechanism
214-13
B7028-S2/441
Fig. 28. Cutaway view of special tools used to install valve guide.
Draw valve guide (6) in using jack screw (1), pull rod (2), stop
(3), centering mandrel (4), and special nut (5).
Fig. 27. Cutaway view of special valve guide removal tools. Withdraw
valve guide (5) using jack screw (1), pull rod (2), spacer sleeve
(3), and special nut (4)
3. Flush the new guide with cold water and fit the guide
into the cylinder head. Working from the combustion
chamber side of the cylinder head, insert the special
tools. See Fig. 28. Draw the valve guide into the head
until the stop is fully seated.
4. Finish the guide using a 7.0 mm undersize reamer
(Saab tool no. 83 93 944). Then Follow up with a 7.0
mm H7 valve guide reamer.
Valves and Valve Seats
Valve and valve seat specifications vary between turbo and
non-turbo models. Exhaust valves are sodium-filled and stellite-coated and should be hand-lapped only. Refacing exhaust valves by grinding will remove this coating and render
the valve useless. Valve and valve seat dimensions are
shown below in Fig. 29.
Whenever work is done on the valves or valve seats, the
valve stem height must be checked. This measurement is crit
ical to proper hydraulic cam follower operation. A special tool
(Saab tool no. 83 93 753) is available to make the measurement, although precision measuring equipment can be substituted.
With the valves installed and the camshafts and cam followers removed, measure the distance between the end of the
valve stem and lowest part of the camshaft bearing surface as
shown in Fig. 30.
NOTE
When using the special Saab stepped tool, lay the tool across
the camshaft bearings so that the long and short legs are directly above the end of the valve stem. See Fig. 31. Check
that the shorter step does not touch the valve (maximum valve
height) and that the longer step raises the tool off the bearing
surface (minimum valve height).
If any fault is found, either grind the end of the valve stem
(valve stem too high) or machine the valve seat (valve stem
too low). If the valve stem is worn, replacing the valve is also
an alternative to valve seat grinding.
VALVE MECHANISM RECONDITIONING
Page 115
214-14
Cylinder Head and Valve Mechanism
--------------------
6.955-6.980 mm
(0.2738-0.2748 in.)
t
I
1.5mm
(0.06 in.)
approx.
•
29.0 mm
(1.14 in.)
JI-
I
Exhaust valve
44.5"
~
t
6.960-6.975 mm
(0.2740-0.2746 in.)
I
32.0 mm
(1.26 in.)
,I
•
1.5 mm
~~::=---~~~~~~7
(0.06 in.)
\:
approx.
JI-
"
1
B7029
Intake valve
Fig. 29. Valve and valve seat dimensions.
Fig. 30. Working range of hydraulic cam follower (valve stem height).
---_.~~-----Scrapping Sodium Filled Valves
C ) C)
CJO
-
All of the fuel injected cars covered by this manual use sodium-filled exhaust valves. The sodium contained in the hollow
stems of the valves is considered Hazardous Waste under the
resource Conservation and Recovery Act. Disposal of used
sodium-filled valves must be done in accordance with local,
state, and federal regulations.
WARNING
Discarded sodium-filled exhaust valves should never, under
any circumstances, be mixed with normal scrap metal as they
are liable to explode when melted down.
To scrap sodium-filled exhaust valves
1. Drill a hole through the center of the valve and into the
sodium compound. See Fig. 32.
VALVE MECHANISM RECONDI170NING
B70SS
Fig. 31. Valve stem height being checked using Saab special tool no,
8393 753.
2. Drill another hole into the stem or cut off the stem approximately 25 mm (1.0 in.) from the end of the stem.
WARNING
When drilling or cutting, keep clear of any water to avoid an
explosion.
3. Throw the valve into a bucket of water and quickly
move at least 10 feet away. See Fig. 33.
Page 116
Cylinder Head and Valve Mechanism
214-15
To quickly check the springs, line them all up in a row. Place
a straight edge across the top of the springs. Any spring that is
significantly shorter than the others (more than 1/16 in.) is
worn and should be replaced. As a finai check, measure the
free height of the spring. Spring specifications are listed below.
Use a high-quality square to check the springs maximum
out-of-square. Place the spring against the square and turn
the spring one full rotation to obtain the largest gap. Measure
the gap between the spring and the square. See Fig. 34.
r-----------;::::::;:::,----------
Fig. 32. Hole being dnlled into sodium-filled exhaust valve.
Fig. 33. Sodium-filled valve being dropped into bucket of water to
neutralize sodium.
4. After about two minutes, the reaction should die down.
Remove the valve from the bucket and dispose of the
valve in the normal way.
Valve Springs
Fig. 34. Valve spring being checked for out-of-square. Make measurement at arrows.
Valve Springs
• out-of-square (maximum)
Valve springs should be checked for squareness and fatigue. Accurately checking for worn springs requires special
spring testing equipment to compress the valve under a specified pressure. Always replace a spring that fails to meet any
specification.
• free height
• height when compressed
with pressure of 131-141 Ibs
1.75 mm
(0.07 in.)
45.0±1.5 mm
(1.77±0.06 in.)
28.4 mm
(1.12in.)
VAL VE MECHANISM RECONOITIONING
Page 117
Camshaft Timing Chain
215-1
215 Camshaft Timing Chain
General
215-1
Camshaft Timing Chain
215-1
Checking Camshaft Timing Chain
Replacing Camshaft Timing Chain
and Tensioner.
To replace camshaft timing chain
215-2
215-2
215-1
GENERAL
The overhead camshafts are driven by a single row chain.
The chain is tensioned using a hydraulic chain tensioner system, which is mounted in the side of the cylinder head. See
Fig. 1. The timing chain and its related components normally
do not require maintenance. If either the chain, the lower
guides or the crankshaft sprocket are worn and need to be replaced, the engine will have to be removed from the car.
CAUTION
The camshafts must always be properly timed to the crankshaft
or the pistons may contact the valve heads resulting in engine
damage. Do not alter the position of the crankshaft or camshafts once the timing chain is removed from its sprockets.
To check the timing chain and its components, remove the
valve cover as described in 214 Cylinder Head and Valve
Mechanism. Then using a wrench on the crankshaft pulley
mounting bolt, turn the engine over in the direction of normal
engine rotation until the camshafts and the flywheel are set to
TDC (OOTDC). See Fig. 2.
CAUTION
Do not tum the engine over using the flats on the camshaft.
NOTE
Normal engine rotation is counterclockwise when viewing the
engine from the front of the car,
Fig. 1. Timing chain and related components used on 16-valve
engines,
CAMSHAFT TIMING CHAIN
Checking Camshaft Timing Chain
The camshaft timing chain and its components can be quickly checked to determine if the chain, sprockets, or guides are
worn or if the chain is incorrectly positioned on it sprockets.
Fig. 2. Camshaft sprocket and crankshaft TDC marks set at OOTDC
Both camshaft marks and the flywheel mark should be exactIyaligned,
CAMSHAFT TIMING CHAIN
Page 118
215-2
Camshaft Timing Chain
If all three marks are not perfectly aligned, either the timing
chain is severely worn or the chain is incorrectly installed. See
Fig. 3 for camshaft sprocket diagnosis. Remove and install
the chain as described to below.
Exhaust
Inlet
camshaft sprockets, the chain tensioner, and the upper chain
guide can all be replaced with the engine installed.
To replace camshaft timing chain
1. Remove the engine as described in 201 Engine Re
moval and Installation.
2. Remove the valve cover and align the camshaft and
the flywheel at TDC as shown above.
3. Remove the oil pump from the timing chain cover as
described in 220 Lubrication System.
4. Disconnect the lower hose from the coolant pump.
5. Remove the alternator with its support bracket.
Correct
6. Remove the bolts from the timing chain cover and remove the cover from the engine. See Fig. 4.
Wom chain
or chain retarded one tooth
Fig. 4. Camshaft timing chain cover being removed.
7. Remove the upper chain guide from above the camshaft sprockets.
Chain advanced one tooth
87068-5211099
8. While holding the camshaft stationary, loosen the two
camshaft sprocket mounting bolts. Use a 19 mm
wrench on the camshaft flats to hold the camshaft. See
Fig. 5.
Fig. 3. Camshaft alignment marks.
9. Remove the chain tensioner from the side of the cylinder head. See Fig. 6.
Replacing Camshaft Timing Chain
and Tensioner
Replacing the timing chain or any of the components behind the timing chain cover will require that the engine assembly be removed from the car. The camshaft timing chain cover
cannot be properly removed with the engine installed. The
CAMSHAFT 77MING CHAIN
10. Remove the camshaft sprockets and the chain. See
Fig. 7.
Page 119
Camshaft Timing Chain
215-3
87071-821258
Fig. 5.
Camshaft sprocket mounting bolt being loosened while camshaft is held stationary.
Fig. 7. Camshaft sprocket being removed from camshaft.
CAUTION
Make sure that the chain is centered on the guides.
14. Preset the tensioner so that it will not tension the chain
when installed. Then install and tighten the tensioner to
the cylinder head.
Fig. 6. Camshaft timing chain tensioner being removed,
CAUTION
The camshafts must always be correctly timed to the crankshaft
or the pistons may contact the valve heads resulting in engine
damage. Do not alter the position of the crankshaft or camshafts once the timing chain is removed from its sprockets.
11. Inspect the chain sprockets, the chain guides, and the
chain tensioners. Replace any sprocket that is visibly
worn. Replace any guide that is deeply scored.
12. With all TOG (timing) marks aligned, install the timing
chain and the exhaust-side camshaft sprocket, making
sure there is no chain slack between the cam sprocket
and crankshaft sprocket.
13. Install the intake-side camshaft sprocket, keeping the
chain tight between the sprockets. Hand tighten the
sprocket mounting bolts.
NOTE
• Two types of tensioners are used on 16-valve engines and
are preset differently. The early-style tensioner can be preset
by fully pressing the spring-loaded piston in and turning it until
it locks. The late-style tensioner, which has a ratcheting mechanism, can be preset by removing the small bolt and spring in
the end of the tensioner. Lift up on the ratcheting pawl and
push the lever all the way in. See Fig. 8.
• The late-type ratcheting tensioner can be retrofitted on all
16-valve cars with the early-style tensioner.
Tightening torque
• timing chain tensioner
to cylinder head
63 Nm (47 ft-Ib)
15. Tension the camshaft timing chain by either installing
the center bolt and spring (late-style tensioner) or by releasing the tensioner piston by pressing on the guide
rail. See Fig. 9.
CAMSHAFT TIMING CHAIN
Page 120
215-4
Camshaft Timing Chain
NOTE
New late-style tensioners come with a safety pin installed. Removing the safety pin will release the tensioner arm. Do not
remove the pin until the tensioner is installed.
Early style
Tightening torque
• camshaft timing chain center
tensioner plug (bolt) to tensioner ... 22 Nm (16 ft-Ib)
~style
Fig. 9. Early-style camshaft timing chain tensioner being released by
pressing on guide rail with blunt object.
16. Rotate the crankshaft by hand in the direction of normal
engine rotation two full revolutions. Recheck that the
TOC marks are all correctly aligned. If any faults are
found reset the timing chain.
CAUTION
Recheck all timing marks carefully. It is very easy to be off one
tooth.
I
87073·S2I1428
J
Fig. 8. Early and late style camshaft timing chain tensioners being
preset prior to installation,
CAMSHAFT TIMING CHAIN
17. Remove the camshaft sprocket bolts one at a time, coat
them with Loctite, and reinstall. Tighten the bolts while
holding the camshaft stationary as shown in Fig. 10.
I
CAUTION
Hold the camshaft steady using a 19 mm wrench on the camshaft flats when tightening the camshaft sprocket bolts. Do not
allow the tensioner or the chain to take this load.