Page 111
Deviations, Saab 99 Combi Coupe
4.3.
4.4.
Treat the joint between the outer wheel housing
and the outer side panel through the hole for the
evacuation box after the latter has been removed.
Treat the trunk lid through the lower hole in the
inner panel of the lid.
44
SUBSEQUENT TREATMENT
Dry off the oil from the oiling points along the sides of
the fenders and on the painted surfaces. Use a rag dipped
in paint thinner. Remove the masking from the brake
discs and fit the wheels. Remove the seals in the drain
holes in the scuff plate members and clean off the oil
which has run out. Put back the floor mats and fasten
the scuff plates. Note! Oil draining must have ceased
when the sealing plugs are removed. Oil which runs out
through the scuff plate member drain holes will dissolve
the insulation mat in the front and middle floor.
S 4753
DEVIATIONS, SAAB 99 COMBI COUPE
SA1'B
141-5
Page 112
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Page 113
CONTENTS
200
GENERAL
201
REMOVAL AND INSTALLATION
210
ENGINE BODY
211
CYLINDER HEAD
214
VALVE MECHANISM
215
TRANSMISSION
216
CRANK MECHANISM
221
OIL PUMP
222
OIL FILTER
223
OIL COOLER
231
CARBURETOR
232
AIR CLEANER
233
FUEL PUMP
234
FUEL TANK AND FUEL LINES
240
FUEL INJECTION
252
EXHAUST SYSTEM
254
EXHAUST EMISSION CONTROL SYSTEM
261
RADIATOR AND COOLING SYSTEM
262
WATER PUMP AND FAN MOTOR
271
THROTTLE CONTROLS
UAEI
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Page 114
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1lon1
Page 115
GENERAL
CYLINDER BLOCK
The car has a four-in-line cylinder, water-cooled overhead
camshaft engine. The crankcase ventilation is totally enclosed. The cylinder block is inclined at an angle of 45°
and the cylinder head is of the cross-flow type, i.e. with
the inlet passageson one side and the exhaust passages
on the other. The engine is mounted with the clutch towards the front of the car and with the transmission and
No. 1 cylinder towards the rear. The engine is available
in two versions: carbureted or with fuel injection.
The carburetor is a horizontal Zenith-Stromberg.
The injection system is manufactured by Bosch and has
the designation Cl. Cl (continuous injection) means that
the injection valves remain open when the engine is running. The air flow to the engine is measured continuously
and this governs the supply of fuel to the engine. The
fuel is injected into the inlet manifold upstream of the inlet valve.
The cylinder block is made of special cast iron, cast in
one piece. The cylinder bores, surrounded by cooling
jackets, are drilled straight out of the block. The block
also contains oil channels for the lubricating system.
CYLINDER HEAD AND VALVES
The cylinder head is made of aluminium. The cylinder
head is bolted to the block. The camshaft is made of special casting and it is seated in bearings in the camshaft
bearing assembly which is bolted to the cylinder head.
The valves are of steel with chromium-plated spindles and
the valve heads are induction hardened.
POWER PLANT, CARBURETED ENGINE AND MANUAL
TRANSMISSION, SEEN FROM LEFT
POWER PLANT, CARBURETED ENGINE AND MANUAL
TRANSMISSION, SEEN FROM RIGHT
POWER PLANT, INJECTION ENGINE AND AUTOMATIC
TRANSMISSION, SEEN FROM LEFT
POWER PLANT, INJECTION ENGINE AND AUTOMATIC
TRANSMISSION, SEEN FROM RIGHT
SA_MI
200-1
Page 116
S 6132
CROSS SECTION OF ENGINE, SIDE VIEW
CROSS SECTION OF ENGINE AT WATER PUMP
200-2
CROSS SECTION OF ENGINE AT DISTRIBUTOR
SA1'EI
Page 117
CRANKSHAFT AND BEARINGS
The crankshaft is forged with ground journals which have
been hardened by tenifer treatment which provides a hard
non-metallic surface giving good protection against wear.
There are five main bearings. The center bearing also acts
as an axial locating bearing. The shaft contains drilled passagesfor lubricating oil. All main bearing shells-can be replaced. The crankshaft also drives a separate idler shaft
which powers the oil pump, water pump and distributor
through cog gears and the fuel pump by a cam.
CAMSHAFT AND VALVE DEPRESSORS
OIL PUMP
The camshaft is cast and has hardened and phosphatized
cams. It is driven by a chain from the crankshaft. The
valves are directly actuated by the camshaft cam via valve
depressors and adjusting pallets.
PISTONS AND PISTON RINGS
The pistons are made of light alloy and are provided with
grooves for two compression rings and one oil scraper
ring. The upper compression ring is flat with a chromed
finish. The lower compression ring has oil-scraping characteristics and is somewhat wider than the upper one. The
actual oil scraper is a three-piece ring.
CONNECTING RODS AND PISTON PINS
The connecting rods are forged and fitted with bushings
for journaling the piston pins. The piston pin bushing
and big-end bearing halves are exchangeable.
The piston pin makes a floating fit in the piston and connecting rod. Its axial movement is restricted by lock rings
in the piston pin holes.
LUBRICATING SYSTEM, OIL FILTER
The engine has a forced lubrication system (see fig. below). Oil pressure is generated by a birotary pump driven
from the idler shaft. The pump and oil filter are mounted
on a special mounting. Its rotors force the oil through a
reducing valve in the pump itself and on through the oil
filter and oil channels to the vari_ouslubrication points.
Each connecting rod bearing has a separate oil channel
from the main bearings. The oil filter is of full-flow type,
i.e. all oil force-fed to the lubrication points goes through
the filter.
SAM!
LUBRICATING
SYSTEM
·For certain markets, where you can expect very hard driving conditions, the cars are fitted with a special oil cooler.
The oil cooler is placed in the coolant hose between the
radiator and the expansion tank. The oil lines to the oil
cooler are connected to an adapter between the oil pump
spacing piece and the oil filter.
IGNITION SYSTEM
The distributor is driven by a gear transmission from the
jackshaft. The rotor arm rotates anti-clockwise. The
order of firing is 1-3-4-2,
cylinder No. 1 being farthest
to the rear. Ignition advance in relation to engine speed
is regulated by a centrifugal governor and in relation to
load by a vacuum regulator.
200-3
Page 118
FUEL SYSTEM
Fuel tank
The fuel tank is located between the back wheels. The
fuel pump on carbureted engines, which is of diaphragm
type, is driven by a special cam on the idler shaft. The
pump is located on the left-hand side of the engine. The
fuel passesthrough a nylon filter in the pump.
Cars with injection engines are fitted with an electric fuel
pump which is mounted inside the fuel tank.
The fuel tank is designed so as to allow internal expansion
of the fuel. The expansion space is opened by a valve which
is actuated by the filler cap.
Fuel tank ventilation
When fuel is poured in, the tank (1) will not be completely filled, and instead the level rises only slightly above the
lower opening on the venting tube (3). The reason for this
is that an air cushion is formed above this level and prevents further filling of the tank.
The formation of this air cushion is due in its turn to the
fact that a spring-loaded valve (5) located in the filler pipe
(2) blocks the upper opening on the venting tube (4) frof'(I
the upper side of the tank.
When the tank cap (7) is screwed on, a lever is actuated
which opens the valve, thus providing a communication
from the upper part of the tank to the surrounding air via
the ventilation hose (6). The hose runs inside the roof
channel, through the left windshield pillar and out into
the engine compartment behind the left wheel housing.
The fuel, which increases in volume when the temperature rises, is now able to expand inside the tank instead
of being pressed up through the filler pipe (2). As the fuel
level becomes lower in course of driving, air is drawn into
the tank via the ventilation hose (6).
FUEL PUMP, CARBURETED ENGINE
____
1
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1
-
5
____ With_tank_~
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3
Ex
Without_tank_cap
___
7
4 7 i
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2
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6
1
S 2951
200-4
FUEL TANK VENTILATION,
ARRANGEMENT
1. Fuel tank
2. Filter pipe
3. Venting tube
4. Venting tube
5. Spring-loaded valve
6. Ventilation hose
7. Tank cap
SA.4'B
DIAGRAM
Page 119
CARBURETOR
Twin-carburetors
The engine is equipped with either one or two ZenithStromberg horizontal carburetors. The carburetor designation on a single-carburetor engine is 175 CD-2, and on a
twin-carburetor engine, 150 CD-2. The carburetor has
only one jet, the cross-section area of fuel flow being regulated by a moving tapered needle. The position of the
needle is determined by the degree of depression in the
carquretor housing, which acts upon a piston in which the
needle is mounted. The needle is of self-centering type, i.e.
it is suspended in springs; this makes it unnecessary to ac.just the alignment of the carburetor jet.
The carburetor is made of light metal. It consists of three
main sections, the central one being the carburetor housing. The bottom section is the float chamber, which surrounds the jet. Up to and including model 1976, the jet
is equipped with an adjusting screw. As from model 1977,
the jet is press-fitted in the carburetor housing and an adjusting screw for the height of the fuel needle has been
fitted outside the carburetor. The top section is the vacuum chamber, the lower boundary of which is a diaphragm in which the piston is suspended. The vacuum
chamber communicates with the carburetor inlet duct
via two channels in the piston.
The depression in the carburetor housing determines the
rate of fuel flow, which is controlled by the needle, as
well as the rate of air flow, which is regulated by the position of the piston in the air duct. In this way the engine
always receives correctly adjusted quantities of fuel and
air under all load conditions.
In principle, carburetors on twin-carburetor engines are
the same as on single-carburetor engines.
Located in front of the two carburetors is an air box
which serves both carburetors and which is connected
to the air cleaner by means of a hose. The inlet manifold
passages from the rear carburetor go to number 1 and 2
cylinders and from the front carburetor to cylinders
number 3 and 4. A connecting passage links the two manifolds and this serves to correct any minor variations in
the fuel-air mixture from the two carburetors.
TWIN-CARBURETORS
Float system
S4409
CARBURETOR
Fuel enters the float chamber through the float valve. The
float, which is double, is located by a bridge on the underside of the carburetor housing. As the fuel level rises, the
float rises with it, and when the correct level is reached,
the float valve is closed by a tongue on the float arm.
Fuel is also drawn into the jet, where the level will be the
same as in the float chamber (engine at standstill). With
effect from 1977 model cars, the jet is fixed in the carburetor housing. On earlier models, the jet could be adjusted.
As from model 1977 (twin carburetors: model 1976),
the carburetor is fitted with a special float chamber vent
valve. When the throttle is closed, air is expelled directly through a venthole in the carburetor. When the
throttle is opened, ventilation of the float chamber
will be by means of the air cleaner connection. On earlier
models, all ventilation is by means of the air cleaner.
1. Jet adjusting screw
2. Float chamber
3. Cover for vacuum chamber
4. Fuel inlet
5. Vacuum nipple
6. Cap for oil damper
7. Carburetor body
8. Fast idle cam
9. Fast idle screw
10. Throttle screw
SAAB
200-5
Page 120
Choke and fast idling
FLOAT CHAMBER VENTILATION,
The carburetor is equipped with a choke device for easier
starting of cold engine.
The choke consists of a valve disc which, when the choke
spindle is rotated, opens four fuel holes of different sizes
in succession as well as opening anemulsion air duct and
freeing the choke fuel mixture duct to the carburetor head.
When the choke button is pulled right out, all four fuel
holes are in operation and the emulsion air duct is wide
open. At intermediate choke positions one or more of the
fuel holes are closed, but the emulsion air duct remains
open as long as any of the fuel holes is open. When the
choke button is pushed right home, this closes both fuel
and emulsion air ducts as well as the starting fuel hole in
the carburetor housing.
Emulsion air is drawn in through a jet from the carburetor housing. Its function is to improve the distribution •
of the choke fuel mixture among the cylinders.
The choke spindle carries a cam to which the pull wire of
the choke control is attached. When the car is driven on
the choke, this cam acts upon the throttle control to raise
the engine idling speed during starting and warm-up.
In the case of twin-carburetor engines, the carburetors
are fitted with separate choke mechanisms, coupled by
means of a connecting rod.
TWIN-CARBURETOR
1. Driver, throttle valve
2. Link arm with throttle screw
3. Ventilation valve
4. Ventilation outlet, stopped engine
5. Ventilation outlet, running engine
2---+-+-.;...;:~
4 -----'l;\Wlll!~--+-tl-
9
10
FLOAT CHAMBER VENTILATION
1. Ventilation
2. Ventilation
11
12
13
through air cleaner
from outside
-i--------14
CARBURETOR
WITH THROTTLE
1. Damper cap
2. Diaphragm
3. Compensating hole
4. Oil damper
5. Float chamber ventilation
6. Float valve
7. Float
8. Spring
9. Fuel holes
200-6
Sll\1'8
---
CLOSED
10. Adjusting screw
11. Vacuum piston
12. Starting fuel hole
13. Throttle
14. Vacuum hole
15. Fuel needle
16. Jet
17. Float chamber