cooling FIAT 500 1960 1.G Workshop Manual

CHAPTER 1
THE ENGINE
1 :1
1 :2
1 :3
1 :4
1 :5
1 :6
1 :7
1 :8
1:9
1 :10
1 :11Description
Engine removal (sedan—all versions)
Engine removal (station wagon)
Engine disassembly (sedan—all versions)
Engine disassembly (station wagon)
Cylinder head removal, servicing and
replacement
Timing gear overhaul
Crankcase and cylinders
Piston assembly
Connecting rods
Crankshaft and main bearings
1 :1 Description
The 'New 500' two-cylinder aircooled engine operates
on the four-stroke 'Otto Cycle' and is fitted directly to
the transmission unit which incorporates the rear drive
assembly as shown in FIG 1 :1 and FIG 1 :2.
With the power unit fitted at the rear several advantages
are obtained including better load distribution to the
wheels when the vehicle is loaded, elimination of propeller
shaft reducing the size of centre tunnel and better use of
available space.
The cylinder block comprises t w o cast iron cylinder
barrels w i t h cooling fins. The bottom of the cylinders fit
into machined seats in the aluminium crankcase.
The aluminium crankcase carries eight studs on which
are located the t w o cylinder barrels w i t h the aluminium
cylinder head on the top.
A two bush crankshaft of special cast iron is fitted into
the lower half of the crankcase. The crankshaft is
F5009 provided with a counterweight and is hollow to allow for
lubrication.
The steel connecting rods have thin wall bearing halves
on the big-end, and bronze bushes in the small-end. The
offset piston pin is of steel and retained in the piston by
two circlips.
Light alloy pistons are used and are of the taper-oval-
shaped type with a maximum diameter at the base of the
skirt, along an axis perpendicular to the piston pin. Pistons
are fitted with four rings as follows, one compression at
the top, two standard oil scraper rings and one side slotted
oil scraper ring.
The one-piece aluminium cylinder head is finned to
provide a larger cooling surface and carries the inlet and
exhaust manifolds.
The inlet passages merge into a single centralized
flange onto which is mounted the carburetter. The exhaust
passages run almost parallel to the axis of the engine. 1 :12
1 :13
1 :14
1 :15
1 :16
1 :17
1 :18
1 :19
1 :20
1 :21
1 :22Flywheel and starter ring gear
The oil pump
Lubrication, oil filter, relief valve
Valve timing
Valve stem to rocker clearance
Engine assembly (sedan—all versions)
Engine assembly (station wagon)
Power plant mounting
Adjustment of generator and fan belt drive
Modifications
Fault diagnosis

The interior of the car can be heated by the engine
warmed air being ducted into the front compartment and
controlled by a lever on the heating system tunnel.
Engine ignition is by a battery, ignition coil and distribu-
tor which is driven by a gear on the camshaft. The engine
is started by an electric starter motor which is mounted on
the gearbox casing and is controlled by a lever located
behind the gearchange lever.
The complete power unit is mounted by a spring support
at the centre of the rear b o d y crossmember and by t w o
rubber pads mounted laterally to the gearbox.
1 :2 Engine removal (sedan—all versions)
To remove the engine from the car proceed as follows:
Raise t h e rear of t h e car and place on firmly based
stands placed under suitable brackets on the underside
of the body.
Disconnect the battery positive terminal clamp from the
battery terminal post. Release the clip securing the main
petrol pipe to the tank sender unit and ease t h e pipe
from the unit. Drain the oil from the engine sump into
a suitably sized container.
D i s c o n n e c t t h e rear number plate light wire (see
FIG 1 : 6) . Release t h e engine compartment lid check
strap from its slot and separate the lid from the body by
sliding the hinge apart.
Remove the cables attached to the ignition coil, also
to the generator and the starter motor. Remove the
starter motor control tie rod.
Release the oil pressure
indicator cable, the main petrol pipeline at the pump,
the accelerator and starting device controls.
Remove the t w o hoses of the heating and cooling
system which are the input hose to the blower and the
hose for the car heating system. Release and lift out the
engine apron. Remove the starter motor mounting bolts
and carefully lift away the motor.
Using a garage hydraulic jack with suitable cradle (see
FIG 1 : 7) or a rope sling relieve the engine weight
from its mountings. Remove the nuts securing the
gearbox to the engine and the flywheel protection
apron.
Remove the bolts fixing the elastic support to the cross-
member. Remove the rear crossmember mounting nuts
noting that the engine earth cable is held by one
mounting nut and lift away the crossmember.
Carefully ease t h e engine away from the gearbox
ensuring that there is no strain placed on the clutch
shaft. Lower the engine to the floor taking care that no
weight is allowed on any of the attachments. 1
2
3
4
5
6
7
8
1 :3 Engine removal (station wagon)
To remove the engine from the station wagon proceed
as follows:
1 Raise t h e rear of the vehicle and place on firmly based
stands placed under suitable brackets on the underside
of the body.
2 Disconnect the battery positive terminal clamp from
the battery terminal post. Release the clip securing the
main petrol pipe to the tank sender unit and ease the
pipe from the unit. Drain the oil from the engine sump
into a clean dry container of suitable size.
3 H o l d t h e rear door open and secure using string to stop
it swinging to the closed position. Secure the luggage
compartment floor panel in its upright position.
F50013 4 Remove the cables attached to the ignition coil, also
to the generator and starter motor. Remove the starter
motor control tie rod. Release the o i l pressure indicator
cable, the main petrol pipeline at the pump, the accele-
rator and starting device controls. Disconnect the air
filter housing.
5 Remove the hose connecting the car heating system
to the engine cowling. Disconnect the clip holding the
air pipe to the blower and carefully disconnect the pipe
from the blower cowling. Remove the starter motor
mounting bolts and carefully lift away the motor. FIG 1:5 120.000 engine assembly: cross-section view
through a cylinder

LID CHECK A R M
FIG 1:6 Engine compartment lid open LID LOCKING
HOOK
NUMBER PLATE
LAMP CABLE NUMBER PLATE LAMP
CABLE JUNCTION
CROSS MEMBER ARR.2O74.
FIG 1 :7 Engine removal using the jack with cross-
member Arr.2074
6 Using a garage hydraulic jack with a suitable cradle
relieve the engine weight from its mountings. Remove
the nuts securing the gearbox to the engine.
7 Remove the nuts securing the rear bumper blade and
panel to the body. Note that the engine earth cable is
held by one mounting nut. Carefully dismantle the
engine elastic mounting or release the bracket from the
engine rear cover by removing the two nuts and washers.
Lift away t h e rear panel assembly carefully making sure
14
FIG 1 : 8 Engine components: crankcase, cylinder head,
timing sprockets cover To dismantle the engine proceed as follows:
1 Remove the exhaust silencer by releasing the two
collars for attachment to the engine and the two con-
nections for the exhaust pipe. It will be noted that
there is one exhaust pipe connection on either side
of the cylinder head.
2 Place the engine on a firm wooden top bench. Remove
the two tappet cover retaining nuts and washers and
lift away the cover. Remove the connection for cooling
air delivery to the sump cooling ducts at the side of
the sump.
3 Remove the air cleaner after first releasing the two
bolts on the air cowling and the two nuts for the air
elbow connection to the carburetter.
4 Remove the generator drive belt by releasing the
three nuts so splitting the semi-pulley. Lift away the
drive belt.
5 Remove all the bolts securing the air conveyor
ducting to the cylinder head, to the crankcase and
also to the engine cowling assembly opposite to the
air conveyor. Release the accelerator control tie rod
and carefully lift away the air conveyor assembly
complete with the generator after first removing the
clamp fixing the generator to the crankcase. 1 :4 Engine disassembly (sedan—all versions) t h a t rear air ducting panels are not strained or the
mating faces damaged.
8 Carefully ease the engine away from the gearbox ensur-
ing that there is no strain placed on the clutch shaft.
Lower the engine to the floor taking care that no weight
is allowed on any of the attachments.

6 Release the ignition distributor support retaining nut
and lift away the distributor together w i t h its support.
7 Remove all the mounting bolts of the engine cooling
cowling and lift away the assembly. Release the t w o
carburetter retaining nuts and carefully remove the
carburetter together with its drip tray.
8 Lift away the valve rocker assembly having first
released the t w o retaining nuts together with the plain
washers and lock washers. Carefully lift out the valve
rocker pushrods noting their relevant positions.
9 Slacken the four central cylinder head cap nuts and
the four conventional nuts in the order, shown in
FIG 1 :44 or 1 :46. Lift the cylinder head from the
barrels. If difficulty is experienced it is essential to use
Fiat tool A.40014 or a similar drilled plate, otherwise
serious damage could be caused if other means are
used (see FIG 1:9).
10 Remove the four pushrod sleeves and the casing
containing the oil ducting to the overhead valve gear.
11 Remove the fuel pump retaining nuts and washers
and lift away the pump. Carefully pull out the pump
control pushrod from the crankcase.
12 Remove the six screws holding the centrifugal oil filter
pulley cover and lift away the cover. Remove the
centrifugal filter mounting flange by unscrewing the
crankshaft central bolt. Also remove the timing cover
containing the oil pump gears and the oil pressure
regulating valve. Note the position of the nuts,
toothed and plain
washers for correct reassembly.
13 Release t h e four camshaft sprocket retaining bolts and
lift away the sprocket and timing chain. Using Fiat
pulley A.46020 or a large universal two-leg puller as
shown in FIG 1 :10 remove the crankshaft sprocket
and its body.
14 Carefully lift out the rocker pushrod tappets making a
note of their location and gently pull out the camshaft
making sure the front bearing bore is not damaged by
the cam lobes or distributor drive gear.
15 Mark the flywheel and crankshaft to ensure correct
reassembly and release the six f l y w h e e l retaining bolts
together w i t h the lockwashers and lift away the fly-
wheel.
16 Using Fiat tool A.60156 on the two central studs, lock
the two cylinder barrels in place as shown in FIG 1 : 1 1.
TOOL A. 40014
FIG 1:9 Tool A.40014 for cylinder head removal
F50015
17 Turn the engine upside down ensuring that no weight
is placed on the studs and remove the oil sump and the
oil suction scoop.
18 Mark the connecting rods and end caps to ensure
correct reassembly and remove the end caps. Place the
engine on its side and remove the cylinder barrels
clamp. Ensure that the studs are clean and carefully
slide off the connecting rod-piston-cylinder assem-
blies from the crankcase.
19 Remove the six screws holding the rear main bearing
housing to the crankcase and lift away the housing.
Remove the six screws holding the front main bearing
housing to the crankcase and lift away the housing.
20 Carefully ease the crankshaft from the crankcase
moving it diagonally to assist withdrawal. FIG 1:11 Cylinder hold-down tool A.601 56 TOOL A.60156 FIG 1 :10 Removing crankshaft sprocket w i t h puller
A.46020
PULLER A.46020

13 Remove all the bolts and washers joining the sump
casting to the crankcase making a special note of the
location of bolts of different lengths.
14 Mark the flywheel and crankshaft to ensure correct
reassembly and release the six flywheel retaining bolts
together with the lockwashers and lift away the fly-
wheel.
15 Using Fiat tool A.60156 on the two central studs, lock
the t w o cylinder barrels in place (see FIG 1 :11).
16 Turn the engine upside down ensuring that no weight
is placed on the studs.
17 Mark the connecting rods and end caps to ensure cor-
rect reassembly and remove the end caps. Place the
engine on its side and remove the cylinder barrels
clamp. Ensure t h a t t h e studs are clean and carefully
slide off the connecting rod-piston-cylinder assem-
blies from the crankcase.
18 Remove the six screws holding the rear bearing hous-
ing to the crankcase and lift away the housing. Remove
the six screws holding the front main bearing housing
to the crankcase and lift away its housing.
19 Carefully ease t h e crankshaft from the crankcase
moving it diagonally to assist w i t h d r a w a l .
20 To ensure no damage occurs to the long cylinder
barrel mounting studs these may be removed using
Fiat puller A.40010 or a universal stud remover as
shown in FIG 1 :12.
1 :6 Cylinder head removal, servicing and replace-
ment
Description:
The aluminium cylinder head is finned to increase the
cooling surface. Through bolts secure the head and the
two cylinders to the crankcase. The valves are controlled
by a camshaft through tappets, pushrods and rockers. The
connection between the head and the crankcase is via five
sleeves mounted directly between the head and crankcase,
and these accommodate the pushrods, lubricating oil and
passage for the crankcase gases. The cylinder head has
been
modified for the 110 F and later 120 engines as
they now incorporate a heater safety device as described
in Section 4 : 4 .
FIG 1:15 Cylinder head
17F500
The cylinder head should be removed whenever the
valves require attention or the engine to be decarbonized.
To remove the cylinder head proceed as f o l l o w s :
1 Remove the air cleaner, carburetter, rocker cover and the
screws securing the blower conveyor to the cylinder Removal of cylinder head: FIG 1 :17 Installing a valve guide using Tool A.60153
provided with pilot bush TOOL A. 6 0 1 5 3 -
WITH PILOT BUSH FIG 1:16 Cleaning valve guides
W I R E BRUSH A.11417 / BIS

Cylinder head installation:
To refit the cylinder head proceed as follows:
Place a new cylinder head joint on the cleaned faces of
the cylinder barrels. Insert the rocker pushrod and
lubrication pipe sleeves together with the relevant
gaskets and rings.
Fit the washers and nuts to the studs and tighten to
fingertight.
Tighten the nuts in the order shown in FIG 1 :44 and
FIG 1 :46 to a torque wrench setting of 18.1 Ibft. Reset
the torque wrench to a new setting of 23.9 Ibft and
tighten the nuts once more in the recommended order.
Replace the pushrods in the correct order.
Refit the rocker shaft ensuring correct location of the
lubrication tube to the rocker shaft and replace the
plain and lockwashers. Tighten the nuts to a torque
wrench setting of 15.2 Ibft. Reset the tappet to rocker
clearance adjustment.
Connect the t w o exhaust side manifolds to the cylinder
head. Using new gasket refit the spark plugs and HT
cables. Replace the rocker cover fitted with a new cork
gasket and blower conveyor to the cylinder head
securing screws. Refit the carburetter and reconnect its
fuel line and controls. Refit the air cleaner and elbow
and connect the rocker cover breather pipe (if fitted).
1
2
3
4
5
1 :7 Timing gear overhaul
Camshaft:
The cast iron camshaft is located in the crankcase and is
supported at either end in sets machined directly in the
crankcase. No bushes are used. The camshaft is driven by
a chain from the crankshaft at half engine speed and
operates the overhead valves through tappets, pushrods
and rockers (see
FIG 1 :20).During engine overhaul the camshaft journals and cam
faces should be free of score marks or signs of seizure and
have a bright mirror finish.
The distributor drive gear should be inspected for tooth
wear which if excessive means that the camshaft must be
replaced.
Tappets:
The tappets should be inspected for signs of seizure or
excessive wear. The end surface that is in contact with the
camshaft should be smooth without signs of excessive
wear. Any slight scratches or indentations may be
removed using a very fine oil stone.
Pushrods and sleeves:
The pushrods operate in special axially resilient sleeves
that are compressed on assembly between the cylinder
head and the crankcase. It is through these sleeves that
the engine sump is vented also through which the oil
returning from the cylinder head passes.
Two rubber O-ring seals are fitted to each sleeve to
ensure an oil t i g h t seal between the cylinder head and
crankcase. The sleeves should be checked for distortion
and exact equal length and when refitting new seals must
always be fitted.
The pushrods should be checked for straightness and
the t w o ends that contact the rocker setscrew and the
F50019
The crankcase is an aluminium casting suitably ribbed
to ensure correct air cooling. The main bearing and cam-
shaft bearing bores are machined as also are the tappet 1 :8 Crankcase and cylinders During valve gear overhauls the clearance between the
rocker shaft bore and the rocker must be checked. The
maximum permissable wear between these t w o parts is
.0059 inch. It is recommended that the part which is most
worn be renewed, or in extreme cases both parts. Rocker and rocker shaft: tappet seat must not show any signs of roughness or
excessive wear. 3 Oil shield (for intake valves only) 4 Snap ring
5 Rocker 6 Upper spring cup 7 Valve spring
8 Lower spring cup 9 Pushrod 10 Tappet
11 Oil seal ring 12 Pushrod sleeve 13 Seal ring 1 Intake valve 2 Upper cup lock Key t o Fiq
1 :20 FIG 1:20 Valve, pushrod and tappet assembly FIG 1:19 Camshaft. The arrow points to the lube oil
outlet port

FIG 1:21 Finned cylinder. Letter A stamped on cylinder
indicates the class to which cylinder belongs, as referred
to its inside diameter
CLASS LETTER
FIG 1 :22 Cylinder measurement points
seats, gearbox companion flange and timing gear cover
mounting flange.
The cast iron cylinders are finned radially to increase the
cooling air surface and are located symmetrically on the
crankcase, each being held by four studs. The cylinders are
installed by sliding into the crankcase bores and finally
held in place by the cylinder head (see FIGS 1 :8 and
1 :21).
Inspect the cylinder bores for score marks, wear and
any other defects or damage. The clearance between the
piston maximum diameter and the cylinder bore should be
checked to ensure that it is within the maximum wear limit
of .0059 inch.
20FIG 1 :23 Checking cylinder diameter by dial gauge
C.687 brought to zero w i t h ring gauge C.672 DIAL GAUGE C 687
RING GAUGE C. 672 The cylinder height must be checked between the seat-
ing face on the crankcase and the top surface and this
dimension should be 3.5433 ±0006 inch.
If this dimension is less than specified the cylinder must
be renewed to prevent possible carbon deposits on the
piston crown and underside of combustion chamber
causing the piston to strike the cylinder head (see
FIG 1 :24). Checking cylinder height: This operation should bring the bore size to correspond
to the oversize piston sizes in order to obtain the correct
clearance between the piston and cylinder. These
limits
are given in Technical Data. It will be observed that the
cylinders are divided into three classes depending on the
bore diameter. The classes are identified by the letters 'A',
'B
1 and ' C , one of which will be stamped on the mating
face with the cylinder head as shown in FIG 1 :21. Pistons
are divided into three classes to correspond with the
cylinder bore sizes. Naturally the piston and bore must
belong to the same class. The maximum available piston
oversize is .0236 inch.
Pistons and rings for the Model 500 sports engine are
not available in oversize dimensions so if the cylinder bore
diameter is above the maximum wear limit new parts must
be fitted.Honing or reboring cylinder bores: It is essential that the diameter measurements are taken
at t w o different heights in the cylinder bore along both the
longitudinal and transverse axles as shown in FIG 1 :22.
It is recommended that to zero the internal micrometer
Fiat ring gauge C.672 is used (see FIG 1 :23).
If bore wear or ovality is between .0059 and .0079 inch
the cylinder bore may be honed. Should however the
wear limit of .0079 inch be exceeded then the bores must
be recut.

After the crankshaft has been reground it is important
that all traces of swarf are removed by constant washing
and then drying with a non-fluffy rag.
The clearance between the main bearings and journals
must be checked before installing the crankshaft in the
engine. It should also serve as a recheck after the
crankshaft has been reground.
Measure the maximum main bearing internal
diameter and the minimum journal diameter using
accurate measuring equipment. The clearance must not
exceed .0039 inch otherwise the journals must be
reground and undersize bearings fitted.
Undersize bearings w i t h .0394 inch stock on the
internal diameter are also supplied unmounted. They
must be press fitted in the supports, the recommended
interference fit being .00039 to .00197 inch. After
pressing the bearing into the support, a hole is drilled in
the bearing in line with the location dowel hole in the
support. The hole is finished with a suitable expanding
reamer, such as Fiat U.0334, and the dowel pressed i n ,
noting that the hollow dowel fits in the flywheel end
support.
The next stage is to heat the assembly in an oven or
oil bath for a period of one hour at 150°C (302°F).
When the assembly has cooled to room temperature,
the bearing is reamed in a lathe to match the crankshaft
journal size.
3
Crankshaft oil seals:
Two inner spring rubber oil seals are located, one in a
special seat in the timing gear cover and the other in the
flywheel end of the crankshaft support and provide oil
tightness. These seals are shown in FIGS 1 :3 and 1 :34.
Whenever the engine is dismantled for overhaul these
seals should be carefully inspected for correct seating and
that the inner seal surface is not worn and that the contact
area is perfect both on the crankshaft and on the fan and
generator drive pulley hub.
Clutch shaft pilot bushing:
A self-lubricating bronze bush is fitted in the end of the
crankshaft as shown in FIG 1 :34 and provides a bearing
for the clutch shaft. Should the bush be worn use Fiat
puller A.40006/1 /2 to remove the worn bush. A new bush
should be fitted using a suitably sized drift.
1:12 Flywheel and starter ring gear
The flywheel should be inspected for wear at the clutch
driven plate contact area. It should be flat and have a
smooth finish.
The ring gear teeth should be cheeked for damage
which if evident, the ring gear must be replaced. To facili-
tate the fitting of a new ring gear on the flywheel, the new
ring gear should be heated in an oil bath to a temperature
of 80°C (176°F). Using a press gently ease the
expanded
ring gear over the flywheel and press fully home.
1:13 The oil pump
Sedan :
A helical-spur gear type oil pump is driven by the cam-
shaft through a front dog drive coupling. The gears are
F50025 To remove the pump from the engine proceed as
follows:Pump removal and reassembly:
Remove the engine rear central support from the timing
gear casing. Remove the filter cover pulley and lift
away the drive belt.
Release the hollow screw attaching the slinger and the
mounting flange of the filter on the crankshaft. Also
release the nuts fixing the timing gear cover to the
crankcase.
Remove the timing gear cover together with the oil
pump assembly and the pressure relief valve.
Lift out the oil pump suction scoop with the filter
screen attached from the sump.
Reassembly of the pump to the engine is the reverse
procedure to dismantling. 1
2
3
4
5 located in a special housing in the timing gear cover and
held in place by a cover plate. The oil pressure relief valve
is mounted on the drive gear shaft guide.
A pump suction scoop fitted with a filter screen is
secured in the crankcase and connects to a duct in the
timing gear case as s h o w n in FIG 1 :36.
2
4
6Key t o Fig 1 :36
Rocker shaft
Ducts, cylinder head oil drain
Oil pressure relief valve
to centrifugal filter
9
with central oil gallery
12Sump cooling air conveyor
indicator sending unitOil filler with vent valve
Line, oil delivery to rocker shaft
Level indicator rod 31
5
7Gear pump
8 Oil duct
Centrifugal oil fitter
1110
Crankshaft
Oil pump intake screen filter
13 Low oil pressure FIG 1:36 Engine lubrication diagram

FIG 1 :44 Cylinder head h o ld-down nuts tightening
sequence. 500 Sedan
TIMING CHAIN ENDCYLINDER No. 1 CYLINDER No. 2 FLYWHEEL END
CAMSHAFT
EXPANSION SLOT C/ROD NUMBERROTATION DIRECTION
FIG 1 :45 The correct position of connecting rod-
piston assembly on engine 120.000
30
screws and together with new lockplates tighten to a
torque wrench setting of 23.1 Ib ft. Bend down the
lockplates.
9 Slide the centrifugal oil filter mounting flange, the
oil slinger and the mounting screw together with its
lockplates onto the crankshaft and tighten the screw
to a torque wrench setting of 108.5 Ib ft. Bend down
the lockplate.
10 Assemble the clutch assembly to the flywheel and
using Fiat pilot A.62023 centralize the driven plate
to the pressure plate assembly. Secure the pressure
plate assembly using screws and toothed washers.
11 Fit new oil pan cork gasket, if necessary using a little
grease to hold in position and carefully fit the oil pan
securing with screws, toothed washers and lock-
plates. Bend down the lockplates onto the screw
heads.
12 Fit the oil cooling air conveyor on the oil pan and
secure with screws and toothed washers.
13 Carefully turn the engine over and fit the centrifugal
filter mounting flange rubber seal. Fit the oil filter
cover and secure with screws together with plain and
toothed washers to a torque wrench setting of
5.8
Ib ft.
14 Ensure t h e faces of the cylinder head and cylinders
are free from dirt and oil and carefully slide the
cylinder head gasket over the studs ensuring that it
is the correct way up. Insert the tappets in the same
order to removal together with the sleeves, pushrods,
oil delivery line to the rocker arm shaft and the casing
with its seal ring.
15 Thoroughly inspect the cylinder head to ensure that
it has been correctly reassembled, carefully slide it
over the studs and secure using the four cap nuts
internally and four standard nuts and plain washers
externally. Tighten the nuts in the order as shown in
FIG 1 :44 or 1 :46 to a torque wrench setting of
23.9 Ib ft.
16 Fit the rocker arm shaft and arm assembly together
with the two supports. Tighten the supports using
screws, plain and toothed washers to a torque
wrench setting of 15.2Ibft. Adjust the tappet-to-
rocker clearance as detailed in Section 1 :16.
17 Temporarily plug the intake duct hole to ensure that
no foreign matter finds its way into the engine.
Install the spark plugs having ensured that they are
clean and correctly adjusted.
18 Reassemble the engine cowling and air
exhaust
throttle valve assembly which should be secured on
the top side using t w o nuts, t w o plain washers and
two toothed washers, on the underside with two
screws and t w o toothed washers, and centrally using
one screw and one spring washer.
19 Fit the toothed washers on the end of the spark plug
electrode and tighten the terminals together with the
special rubber boots.
20 Refit the fan, generator and ground cable assembly
and secure the crankcase, also the warmed air intake
shrouding. Finally tighten the generator to fan nuts.
21 Fit both lower exhaust silencer mounting brackets
onto the crankcase but do not tighten fully. Fit the
air conveyor and secure to the engine cowling using
six screws, six toothed washers and one nut together
with a toothed washer. Join together the t w o

Air cleaner—station wagon:
A pleated paper air cleaner element is housed in a
special air intake chamber connected to the front of the
engine air cooling cowling (see FIG 4 : 2) . This chamber
will be seen located towards the rear of t h e power unit
compartment. Remove the retaining wing nut, lift off the
lid and the element can be withdrawn by lifting upwards.
2:10 Blow-by-gases recirculation device
Engine 110 F.000
All the oil vapours and blow-by-gases that are formed
in the engine crankcase are drawn to the cylinder head
cover recess 1 (see FIG 2:18). From here they travel into
the pipe 5 via a breather valve 2 which is firmly attached to
the oil filler cap 3 and the strainer 4 located in the filler
neck. The oil vapours and gases are then d r a w n back into
the duct 9 from the pipe 5 which connects the air cleaner
6 to the carburetter 7. This ensures a complete closed cir-
cuit circulation.
Engine 120.000:
From engine No. 288156 the oil vapours and blow-by-
gases instead of being exhausted to the atmosphere are
conveyed to the air cleaner and from here they are drawn
back into the combustion chambers. To ensure that an
excessive of oil vapour does not pass along the piping
with the blow-by-gases a diaphragm is fitted in the duct
in front of the breather valve 2 (see FIG 2 :18), the dia-
phragm comprising a filter gauze 11 and moveable parti-
tion 10.
It should be noted that the oil vapour strainer 4 (see
FIG 2:18) and the flame trap 8 can easily be removed
from their seating for cleaning or renewal.
2 : 1 1 Fuel tank
The fuel tank is located in the front compartment as
shown in FIG 2:19, it comprises a filler union fitted with a
cap, a fuel reserve supply indicator sender unit and a con-
nection incorporating a filter for the main fuel supply pipes.
To remove the tank proceed as follows:
1 Remove the contents of the front compartment includ-
ing the spare wheel and tool bag.
2 Disconnect the main fuel line at the sender unit and also
disconnect the cable to the fuel reserve supply indicator.
3 Remove the four screws together w i t h the clips that fix
the tank to the body and carefully lift away the fuel tank.
4 Carefully drain the contents of the tank into a clean dry
container of a suitable capacity.
Fuel tank—sedan (110 F.) and station wagon (120):
The fuel tank is arranged in the front compartment as
shown in FIG 2 :20. To remove the fuel tank proceed as
follows:
1 Remove both screws which secure the front ends of the
clamping bands to the dash panel. The screws are
shown by arrows in FIG 2 :20.
Petrol tank cleaning:
The tank must be thoroughly checked for leaks espe-
cially at the joint seams. Should a leak be found it is
F50045
advisable for a garage to attend to this as it is very dange-
rous to apply heat to a petrol tank without first taking strict
precautions and a garage will be in a better position to do
this. To clean the tank interior, remove the drain plug and
spray in a jet of air or petrol so that all sediment and dirt
deposits can be loosened. Then vigorously shake the tank.
Flush the tank w i t h petrol and blow the tank dry. Repeat
this procedure until the tank is clean. Refit the drain plug.
Whilst the petrol tank is away from the car it is advisable
to disconnect the fuel feed pipes at the pump and the
carburetter and ensure that these are clear by using an air
jet to one end of the pipe.
Key t o Fig 2 :20
Note Arrows point to fuel tank clamping band screws vent valve
indicator tank unit1 Fuel tank2 Filler cap with
3 Fuel suction pipe and reserve supply
4 Tank clamping bands
FIG 2:20 Location of the fuel tank in front compart-
ment, 500F, L FIG 2:19 Fuel tank in front compartment. The fuel
reserve supply indicator (red light) glows when fuel
amount in tank is less than .8 to 1.1 Imp galls, or 5 litre FUEL TANK
FUEL LINE TO PUMP
FUEL GAUGE CABLE