FIAT 500 1957-73 Workshop Manual Autobooks Models Covered Fiat New 500 Fiat 500D Fiat 500F Fiat 500L Fiat and Autobianchi Giardiniera Blank Page Blank Page Blank Page Blank Page Blank Page Blank Page Blank Page CHAPTER 1 THE ENGINE 1 :1 Description 1 :12 Flywheel and starter ring gear 1 :2 Engine removal (sedan—all versions) 1 :13 The oil pump 1 :3 Engine removal (station wagon) 1 :14 Lubrication, oil filter, relief valve 1 :4 Engine disassembly (sedan—all versions) 1 :15 Valve timing 1 :5 Engine disassembly (station wagon) 1 :16 Valve stem to rocker clearance 1 :6 Cylinder head removal, servicing and 1 :17 Engine assembly (sedan—all versions) replacement 1 :18 Engine assembly (station wagon) 1 :7 Timing gear overhaul 1 :19 Power plant mounting 1 :8 Crankcase and cylinders 1 :20 Adjustment of generator and fan belt drive 1:9 Piston assembly 1 :21 Modifications 1 :10 Connecting rods 1 :22 Fault diagnosis 1 :11 Crankshaft and main bearings 1 :1 Description provided with a counterweight and is hollow to allow for The 'New 500' two-cylinder aircooled engine operates lubrication. on the four-stroke 'Otto Cycle' and is fitted directly to The steel connecting rods have thin wall bearing halves the transmission unit which incorporates the rear drive on the big-end, and bronze bushes in the small-end. The assembly as shown in FIG 1 :1 and FIG 1 :2. offset piston pin is of steel and retained in the piston by With the power unit fitted at the rear several advantages two circlips. are obtained including better load distribution to the Light alloy pistons are used and are of the taper-oval- wheels when the vehicle is loaded, elimination of propeller shaped type with a maximum diameter at the base of the shaft reducing the size of centre tunnel and better use of skirt, along an axis perpendicular to the piston pin. Pistons available space. are fitted with four rings as follows, one compression at The cylinder block comprises two cast iron cylinder the top, two standard oil scraper rings and one side slotted barrels with cooling fins. The bottom of the cylinders fit oil scraper ring. into machined seats in the aluminium crankcase. The one-piece aluminium cylinder head is finned to The aluminium crankcase carries eight studs on which provide a larger cooling surface and carries the inlet and are located the two cylinder barrels with the aluminium exhaust manifolds. cylinder head on the top. The inlet passages merge into a single centralized A two bush crankshaft of special cast iron is fitted into flange onto which is mounted the carburetter. The exhaust the lower half of the crankcase. The crankshaft is passages run almost parallel to the axis of the engine. F500 9 Mounted on the top of the cylinder head is the overhead valve rocker mechanism that is operated by a chain driven camshaft through tappets and vertical pushrods. The carburetter is of the downdraft type fitted with a starting device that is controlled by a lever on the central floor tunnel. A pleated paper element air cleaner and silencer is fitted to the carburetter air intake. A mechanical diaphragm type fuel pump operated from the camshaft by a pushrod, supplies petrol to the carburetter from a fuel tank located at the front of the vehicle. Engine lubrication is provided by a gear pump driven from the camshaft and mounted within the timing cover drawing oil from the engine sump. The oil is cleaned by a centrifugal filter situated at the rear end of the crankshaft and pressure is controlled by a valve mounted on the pump body. Crankcase ventilation is provided for through a rubber hose connected to the top of the rocker cover. The engine is cooled by air from a centrifugal blower mounted on the generator shaft and housed in a specially designed cowling conveying air to and around the engine. FIG 1:1 Left side view of the power plant to suit The air temperature is governed by a special thermostat 500 Sedan fitted in the engine cowling. FIG 1:2 Right side rear three-quarter view of the power plant for 500 Station Wagon 10 FIG 1:3 Engine section through crankshaft, pistons and valves F500 11 FIG 1:4 Engine cross-section through a cylinder 12 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 body crossmember and by two rubber pads mounted laterally to the gearbox. 1 :2 Engine removal (sedan—all versions) To remove the engine from the car proceed as follows: 1 Raise the rear of the car 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 suitably sized container. 3 Disconnect the rear number plate light wire (see FIG 1 :6). Release the engine compartment lid check strap from its slot and separate the lid from the body by sliding the hinge apart. 4 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. 5 Remove the two 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. 6 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. 7 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. 8 Carefully ease the 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. FIG 1:5 120.000 engine assembly: cross-section view 1 :3 Engine removal (station wagon) through a cylinder To remove the engine from the station wagon proceed as follows: 1 Raise the rear of the vehicle and place on firmly based 4 Remove the cables attached to the ignition coil, also stands placed under suitable brackets on the underside to the generator and starter motor. Remove the starter of the body. motor control tie rod. Release the oil pressure indicator 2 Disconnect the battery positive terminal clamp from cable, the main petrol pipeline at the pump, the accele- the battery terminal post. Release the clip securing the rator and starting device controls. Disconnect the air main petrol pipe to the tank sender unit and ease the filter housing. pipe from the unit. Drain the oil from the engine sump 5 Remove the hose connecting the car heating system into a clean dry container of suitable size. to the engine cowling. Disconnect the clip holding the 3 Hold the rear door open and secure using string to stop air pipe to the blower and carefully disconnect the pipe it swinging to the closed position. Secure the luggage from the blower cowling. Remove the starter motor compartment floor panel in its upright position. mounting bolts and carefully lift away the motor. F500 13 that rear air ducting panels are not strained or the NUMBER PLATE LAMP mating faces damaged. CABLE JUNCTION 8 Carefully ease the engine away from the gearbox ensur- ing that there is no strain placed on the clutch shaft. NUMBER PLATE Lower the engine to the floor taking care that no weight LAMP CABLE is allowed on any of the attachments. 1 :4 Engine disassembly (sedan—all versions) 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 LID LOCKING the two tappet cover retaining nuts and washers and HOOK 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 LID CHECK ARM 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 FIG 1:6 Engine compartment lid open also to the engine cowling assembly opposite to the air conveyor.