Description

DESCRIPTION

The engine has 4 opposed cylinders, double camshaft for each cylinder head, two valves per cylinder controlled by hydraulic tappets and BOSCH MP3.1 multipoint electronic injection and static ignition for the 1.6 engine and IAW for the 1.3 engine.

The clutch - gearbox - differential unit is connected behind the engine and forms an integral part of the power unit.

The latter is front mounted and set longitudinally with a 3° inclination.

The power unit is fastened to the body by "suspension" type mounts through a support frame connected to the gearbox - differential unit. The various connections of the power unit to the support frame and to the rear support are made with appropriate flexible mounts to absorb engine vibrations.

The fuel supply system, with unleaded petrol, combined with the suitable antipollution systems described in the specific paragraphs, ensure low exhaust emission levels meeting "USA 83" regulations.

CRANKCASE

This is a single cast iron block with high mechanical strength.

The crankshaft is supported by 3 main bearings which house the same number of thin-walled half bearings. The cylinders are machined directly in the crankcase and they are selected in five classes of dimensions. If cylinder wear exceeds the specified values, they must be bored to the specified diameters according to the oversizes of the pistons available from Spares (see CPT).

Special grooves machined in the crankcase walls allow the circulation of coolant fluid and lubricating oil.

CYLINDER HEADS

This is one-piece, compact and chill-cast in aluminium and silicium alloy.

The camshaft bearings are fastened on the cylinder heads, these too, are made from aluminium and silicium alloy.

The camshafts, controlled through toothed belts, turn on three supports.

The valve guides are force-fitted in their housings on the cylinder heads by interference and the inside diameter is perfected after assembly using a specific reamer and checked using a pair of no-no go gauges.

The seals between the cylinder heads and crankcase are of the ASTADUR type.

Oil spray jets installed on the front and centre main bearing caps spray oil on the piston crowns to partially cool them.