Page 21
Heating and
ventilation
As already mentioned, one of the funda-
mental directives to the designers of the
Saab 99 was that the car should be equipped
with a heating and ventilation system
suitable for Scandinavian winter conditions,
And this is exactly what it has, alrhough
several significant improvements have been
made over the years. Even in extremely cold
weather, the engine is casy to start, and
requires a surprisingly short time to reach
normal working temperature, So it does not
take very long, after a cold start, before the
heating system begins to distribute warm air
to the interior,
Whenever required, the fresh air system
delivers a welcome flow of cool air to the in-
terior. The air supply — be it cold or
warm — can be intensified by means of a fan
with two speed ranges. The rate of air flow
through the interior is very high. Under
normal driving conditions, the air in the
interior is changed about twice a minute,
ata road speed of 25 miles per hour, When
the fan is switched on, the capacity increases
to double the speed,
When the car is travelling, the interior air is
changed continuously and without drafts, At
low speeds, the air flow can be increased by
means of a fan, Cold or heated air is
admitted to the interior through 16 vent
openings. Fresh air vents are fitted at each
extremity of the dashboard, These vents
admit cold air into the interior, air which has
not passed through the heat exchanger, The
vents are provided with adjustable grilles
ins
which can be used to direct the air in the re-
quired direction, The flow of incoming air
can also be controlled separately. Openings
are provided at the extreme rear of the
passenger compartment adjacent to the rear
window, and air is discharged through
these openings to the outlets on the sides of
the body. The locations of the outlets have
been derived from wind tunnel tests. Maxi-
mum suction, without the risk of drawing in
exhaust gases, has thus becn attained,
Air is admitted through a grille located at the
rear of the hood. The air is then routed either
through the heat exchanger or directly into
the fresh air vents.
Contrals for setting the temperature and the
air flow into the interior are provided at the
center of the dashboard. The knob which
controls the temperature of the air supplied
from the heat exchanger is market TEMP.
The selected temperature level is basically
maintained constant, regardless of fluctua-
tions in the air speed and cooling water tem-
perature. A thermostat actuates the water
valve in the heat exchanger, thus controlling
the heat supplies,
The front and rear areas of the interior are
provided with warm air outlets at floor level.
Both outlets are split, so that one air stream
is directed towards the right-hand side and
the other towards the left-hand side. The
VENT knob to the right of the dashboard
center controls the air flow to the floor at the
front, The left-hand control on the console
between the seats determines the intensity of
the warm air stream to the rear footwell.
The DEFR knob to the left controls the
warm air flow towards the windshield. If it is
required to concentrate the defroster action
for maximum effect on the windshield and
side windows, the air supply to the foor-
Qu
wells and rear window can be shut off, and
the fan can be set co full speed. The warm air
flow to other inlets in the interior can
obviously also be increased by resetting the
knobs and controls. However, the capacity
of the heating system is so large that this will
only be required in exceptional cases.
Two large defroster nozzles at the top of the
dashboard direct jets of air onto the wind-
shield, to ensure that it will always be de-
fogged, The knob also controls the air flow
onto the side windows at the front — from
holes in the windshield pillars.
The console between the front seats includes
controls for adjusting the air flow to the
footwells at the rear and to the rear window.
The location of the controls allows the back
seat passengers to adjust the climate” in
their area of the car.
The efficient rear defroster clears the rear
’ window very quickly, Warm air is discharged
through four nozzles directly onto the rear
window at exactly the right height to ensure
unimpaired rear vision.
The Saab 99 WagonBack has a double de-
froster device for the rear window, Warm air
is blown onto the rear window from nozzles
located on each side, Wires in the rear
window are provided for electric defrosting.
The electric heating is controlled by means of
a switch at the center of the dashboard. A
green warning light indicates when the rear
window is electrically heated. On the Wagon-
Back, the ventilation air is discharged
through openings in the side panels of the
luggage compartment.
Page 23
™
To see and be seen
When driving on dirty roads, it will soon be-
come obvious that vision through the wind
shield rapidly becomes reduced by dirt.
he windshield wipers work quickly and
efficiently. The wipers are cable-driven, and
the slope of the driving shafts is such that the
wiper blades are in perfect contact with the
windshield. When assisted by water sprayed
by the washers, the wipers will keep the
windshield clean even when driving the car
under very difficult conditions, The wipers
are matt-black for anti-glare reasons,
The windshield wipers and washers are
actuated by means of a common lever at
fingertip level on the right-hand side below
the steering wheel, The control positions of
the lever are in the same plane as the steering,
wheel
1, Windshield wipers at low speed
2. Windshield wipers at high speed
3. Windshield wipers at high speed with
washers
4. In addition, by moving the stalk against
the spring towards the steering wheel rim,
the windshield will be washed. Provision for
washing the windshield before the wipers are
started protects the windshield from scratch-
ing and reduces the wear on the wiper blades,
especially when the dirt on the windshield is
dry.
Few cars can match the Saab 99 as regards
the rear window remaining clear on the in-
side and outside. The fact that the rear
window does not tend Lo pick up dirt is due
to the favorable aerodynamic shape of the
car. The acrodynamic design of the Saab 99
WagonBack prevents dirt from collecting on
the rear window even under difficult road
conditions.
(\ The rear lights on the Saab 99 WagonBack
“C2 are designed so that all functions will be
clearly visible to other road users, even dia-
gonally from the side. The rear light is
directed to the rear and diagonally to the
side, to facilitate reversing maneuvers in the
dark. The rear license plate illumination is
built into the handle of the rear door fields.
The direction indicator lights at the front are
’ jarge and are located so that they will be
clearly visible from the front and sides,
The headlights interlock is connected to the
ignition lock. The headlight will be switched
on and off as the ignition is switched on and
off, provided that the light switch is in the
"on" position. For safety reasons, many
drivers prefer to drive with the headlights
switched on even during the day, particularly
since the interlock elimirtates the risk of
forgetting to switch off the headlights after
parking the car.
The drawing above illustrates interior
lighting: There are two overhead lamps pro-
vided for interior lighting — one on the left-
hand side of the roof, and another above the
windshield behind the rear view mirror, The
latter is directed onto the passenger seat, to
allow the passenger to read a map, for in-
stance, without the light irritating the driver.
Both lamps, as well as the indirect illumina-
tion of the ignition lock, light up auto-
matically when a door is opened. A con-
yeniently located switch for the interior light-
ing is provided on the console between the
front seats. When the trunk lid is opened, a
light in the trunk will automatically go on.
Page 25
24
Bumpers
However carefully and considerately you
drive, you may still be hit by another car in
rush-hour traffic, skid against another car
on a slippery road or bump against a post
while parking, Slight collisions of this kind
may occur in many ways, and they often
result in costly and irritating damage.
In the United States, where the federal
authorities and insurance companies have
fong demanded better car bumpers, an
official directive specified that all cars sold in
the United States, beginning with the 1973
models, should be capable of being driven
against a fixed barrier at a speed of
5 miles per hour, without sustaining any
damage to controls, headlights, direction in-
dicators, etc. The car must also be capable of
rear collision into the barrier at the same
speed, without sustaining corresponding
damage. These speeds may seem somewhat
low, but a pre-1973 car which collides at that
speed without being fitted with special
bumpers will sustain damage which may cost
more than $250 to repair.
The bumpers protect the car in collisions at
L speeds up to § miles per hour. After being
compressed, the bumper will revert to its
original shape,
The picture shows the construction of the
bumper. Compressible cellular plastic blocks
ar¢ fitted in front of a sturdy aluminium
section, In the event of a collision, the
cellular blocks absorb energy by undergoing
temporary deformation. When the external
pressure is relieved, the blocks will revert to
their original shape. Strong support
members and reinforcements in the body-
work ensure that the impact will not damage
the car. A plastic rail is fitted between the
black rubber casing and the cellular blocks,
and a stainless steel strip is fitted on the out-
side.
3) All models of the Saab 99 can withstand
@ collisions from the front or from the rear at a
speed of 5 miles per hour without the car
sustaining damage. The bumpers are "'self
repairing"’, and will resume their original
shape after being depressed. If all traces of
the mishap are to be removed, only the stain-
less steel strip may have to be replaced, and
possibly one of the cellular blocks. But this
is simple and inexpensive.
The pictures show a test in which a Saab 99
was driven straight into a post at a speed of
5 miles per hour. The pictures illustrate
clearly how the bumper has been compressed
at the point of impact, and how it has
resumed its original shape after a few
minutes, without the body being damaged in
any way. The mark on the strip is the only
visible sign of the impact.
Page 27
ov
Engine
All models of the Saad 99 are equipped with
a water-cooled four-cylinder in-line engine
with an overhead camshaft. The engine
block is made of special cast iron and the
cylinder head is an aluminium alloy casting.
The crankshaft and camshaft are both
mounted in five bearings. The engine is
manufactured in three versions, with one or
two carburetors, or with mechanical fuel
injection, for the U.S.
The cylinders are inclined at an angle of
45° to the right, and the engine is located so
that its clutch end is at the front and the cam-
shaft drive is nearest the bulkhead. The
cylinders are numbered from the rear for-
ward, The cylinder head is of the cross-flow
type, and closed circuit crankcase ventilation
isemployed, The water pump, oil pump and
distributor are driven by a special shaft with-
in the engine. The intake and exhaust mani-
folds are located on opposites sides of the
cylinder block. Hence, it was possible to de-
sign them for optimum low-speed per-
formance of the engine, and the optimum
“breathing” at high speeds, The piston
stroke is 3.07 inches and the engine can thus
withstand high speeds, without unnecessarily
high average piston speed or inertia forces,
However, the stroke is not so short that the
low-speed torque is affected.
‘The crankshaft is a high-grade steel forging
with ground journals, It is dynamically
balanced and is kept within close dimen-
sional tolerances. The diameters of the big-
end bearings and the five main bearings are
so large that they overlap each other toa
significant extent, and this renders the crank-
shaft exceptionally stiff and vibration-free,
The valve mechanism also illustrates that the
engine is designed to work smoothly and
without vibrations, Since the engine is pro-
vided with an overhead camshaft, i.e. since it
is located in the cylinder head, it acts directly
on the tappets, without the need for push-
rods, which only serve to increase the mass
of the moving parts, which gives rise to noise.
The camshaft is supported by a carrier which
can be removed from the cylinder head. In
out the valve clearance being affected. In
order to simplify service work, the cylinder
head bolts are readily accessible without the
need for dismantling the camshaft and valve
mechanism. The camshaft is driven by a
double chain,
To ensure reliable lubrication even under
difficult operating conditions, the engine is
provided with separate oil passages from the
main bearings to each big-end bearing. The
engine is integral with the clutch, gearbox
and differential, and forms a complete
power package which saves weight and
space, (It does not encroach on the passenger
compartment because there is no conven-
tional! propeller shaft, and no heavy power
transmission components at the rear), Power
is transmitted from the clutch through a
primery gear train to the gearbox and
differential located below the engine,
Cars with manual gearboxes are equipped
with hydraulically operated, single dry plate
Borg & Beck clutches, The primary gear train
consists of toothed gears. The clutch is
effectively cooled by being located at the
front of the engine, and this contributes to a
long service life of the lining. Moreover, this
jJocation simplifies service work on the
clutch.
The gearbox is very sturdy. It has full syn-
chromesh in four forward speeds. It's
separated from the engine crankcase by a
partition, but is integral with the final drive
und differential, to form a unit with its own
lubricating system. The drive shafts have
double universal joints, the outer being of
the Rzeppa type, which ensure smoother
steering and less vibration in the steering
wheel during heavy cornering. The inner and
outer universal joints are both permanently
lubricated. Splash lubrication and oil cir-
culation are employed for the power trans-
mission, The final drive crown wheel pumps
olf through a passage to the gearbox and
primary gear, Oil runs back to the final drive
through other passages. Cooling fins are
provided on the inside and outside of the
gearcase, and heat is dissipated through these
fins to keep the oi! cool,
The air cleaner has a paper element and,
apart from cleaning the intake air, also acts
us an intake silencer,
‘The exhaust system is run in a tunnel under
the floor of the passenger compartment and
is thus completely protected from damage on
rough roads. The system consists basically of
the front exhaust pipe, transverse silencer
and rear exhaust pipe. The aluminized sheet
steel in the end walls of the silencer have a
thickness of .070inches. The end walls are of
an expanding design to provide high strength
at the most exposed points, This method has
been employed to reduce the temperature
stresses which would otherwise occur in the
welded joints.
Page 28
2 litre single carburetter engine
Page 29
uw
mR
The radiator is of the cross flow type with a
two-row core. The cooling capacity of the
radiator is sufficient even when the car is
driven in hilly country towing a trailer. A
separate expansion tank is provided to avoid
loss of coolant by accepting a temporary
excess and topping-up the system as it cools.
The cooling water pump has a very large
capacity and induces the coolant to flow at
high velocity across the hottest parts of the
cylinder head, The cooling water also cir-
culates through passages between the
cylinders, The parts of the engine which
require most cooling are thus provided with
the best cooling. The cooling is thermo-
statically controlled by means ofa reliable
wax thermostat. Due to the efficiency of the
cooling system, a relatively small amount of
coolant is required, and this ensures rapid
heating of the engine after a cold start. The
engine is mot equipped with a belt-driven
cooling fan, This allows for faster warm-up
of the engine. The cooling fan is driven by an
electric motor and is switched on by means
of a temperature switch whenever required,
¢.g. when operating at very low stop and go
speeds.
Mechanical fuel injection
The Cl injection system on the two-litre
engine supersedes the earlier electronic
system, The letters '’CI’’ stand for Con-
tinuous Injection, i.e. injection takes place
continuously. The Cl system contains
appreciably fewer electronic components
than the earlier system, and is other wise
significantly simple, In addition, the Cl
system gives cleaner exhaust gases.
This is how the system works:
The fuel pump (3) pumps the fuel from the
tank (2) to a pressure accumulator (4), The
fuel then flows through a filter (5)to a fuel
distributor (15), A constant pressure valve
(13) maintains constant fuel pressure, The
system also includes an air metering unit con-
sisting of a metering disc (6) mounted in the
tapered opening into which the air is drawn,
The air flows through the cone from below,
The metering disc assumes a certain position
in relations to the intake air flow, and this is
determined by the speed of the engine and
the position of the air butterfly'vatve (1). The
larger the amount of air flowing through the
tapered opening, the higher will the metering
disc (6) be raised. A lever (7) connected to the
metering disc actuates a control plunger (8).
The higher the metering disc is raised, the
higher the control plunger will be lifted, and
the fuel flow increases in direct proportion to
the air flow,
It is thus the air flow which actuates the
metering disc, and the latter moves the
control plunger upwards, The space above
the control plunger is occupied by fuel under
pressure. A vertical slot is provided for each
engine cylinder. As the plunger is lifted, the
slots are gradually exposed, thus supplying
the correct amount of fuel to the cylinders,
To ensure that all cylinders are supplied with
exactly the right amount of fuel, the
metering system is equipped with a differ-
ential pressure valve (9) for cach slot, This
valve maintains a constant pressure drop
across the plunger.
From the fuel flow distributor, the fuel is
delivered to the injection valve (10) of each
cylinder. The valve is spring-loaded and
opens at a pressure of 43 p.s.i,, and injection
then takes place continuously, When the
engine is stopped, the pressure in the system
is reduced to 28 p.s.i. and injection ceases.
‘This pressure is maintained by the pressure
accumulator for along period, thus pre-
venting vaporization of the fuel and facili-
tating starting when the engine is hot.
During cold starting, extra fuel is injected
through the cold starting valve (11) at the
instant of starting. This valve is controlled by
athermostatic transducer (12). In addition,
acontrol pressure valve (14) is provided to
reduce the pressure above the controt
plunger, thus raising the plunger and pro-
viding a richer mixture, The contro! pressure
valve is actuated by the engine temperature,
thus eliminating the need for a choke.
Automatic transmission
The Saab automatic transmission is the
Borg-Warner type 35, The integration with
the engine is special to Saab, The torque con-
verter, chain, gearcase and differential are
integrated into one unit, and the automatic
control is incorporated at the front end of
the gearcase, for ease of access through a
cover in the front floor.
The drive is transmitted from the engine toa
hydrodynamic torque converter, from which
it is transmitted by a chain to the automatic
gearbox, The torque converter is oil-filled
and has three main components, i.c, the
purnp impeller, turbine and stator, The
pump impeller is connected to the engine
crankshaft, whereas the turbine drives the in-
put shaft of the gearbox, The stator is
mounted on a free wheel coupling witha
fixed hub. The oil delivered by the pump im-
peller causes the turbine to rotate. When the
driving and driven blades rotate at different
speeds, the stator returns the oil to the pump
impeller in such a direction that the torque
on the pump impeller is increased. The
torque amplification can vary from a maxi-
mum of about 1.9:1 down to 1:1 and amplifi-
cation will cease when the turbine rotates at
about 90% of the pump impeller speed.
‘The tarque convertor’s ability to increase
engine torque helps to provide the car with
good acceleration from low speeds. The Saab
automatic transmission thus has a large
amount of overlap, This eliminates the
constant changing up and down between 12
and 28 miles per hour, Gear changing takes
place automatically by a hydraulic system,
incorporating a pump, regulator, yalves and
servo pistons, actuating the various units in
the gearbox, taking into account the position
of the gear lever and other operating con-
ditions. The kickdown gear is available at
speeds below 53 miles per hour by depressing
the accelerator to the floor,
The Saab automatic gearbox provides the
average motorist with appreciably simplified
and safer driving, In addition, the automatic
operation of the gearbox allows the driver to
employ the maximum performance of the car
for safer passing,
Driving will be more convenient, especially
in city traffic and when parking, starting up-
hill or towing a trailer. The automatic trans-
mission also reduces the wear on the tires and
transmission components.
Although the fuel comsumption of a car with
an automatic transmission is normally
higher, that on Saab 99 models equipped
with automatic transmission is very close to
the consumption of the models equipped
with o manual gearbox. Practical tests have
also shown that, other than in city driving,
the engine with an automatic transmission is
equivalent to that with a manual gearbox in
terms of fuel consumption,
Note that a special of] cooler is required
when towing a trailer. Moreover, a car with
an automatic transmission cannot be started
by towing, since the oil pump of the gearbox
is driven by the engine.
Page 30
A @ gear-changing chart
for normal driving
B @ gear-changing chart
at full throttle
C = gear-changing chart
on kick-down
‘The upper bars indicate when
gear-changing will occur when
accelerating, whereas the lower
bars indicate changing-down
during retardation (raking),
Kmih