199001832 - INTRODUCTION - PISTONS AND CONNECTING RODS

CONSTRUCTION SPECIFICATIONS

The connecting rods are made from spheriod cast iron. The gudgeon pins are the fixed type and are hot matched with the connecting rod.The connecting rod comprises a casing or shank, with a rectilinear axis, which rigidly connects the small end, hinged to the gudgeon pin; and the big end, hinged on the crank pin with bearings in between.The big end is divided into two sections for fitting reasons: the fixed part is in one piece with the casing and the moving part is connected to the former by studs.The two sections are divided by fracture lines to guarantee correct matching. This technique combines simple construction with low production costs.Since the connecting rod is subjected to compression and combined compressive and bending stress forces it tends to become distorted; as a result the connecting rod body should be made in such a way as to combine lightness with maximum resistance and is therefore contructed with a double T section.The connecting rod is the main element connecting the piston with the crankshaft.The pistons are made from silicon aluminium alloy and are divided into three size categories with an arrow stamped on the crown to indicate engine rotation direction to ensure correct installation.