The connecting rods are of hardened and
tempered steel, with copper bush (1) in which the gudgeon pin (2) fits.The floating gudgeon pins are secured by
two circlips (3) seated in specific grooves in the piston skirts.
PISTONS
The aluminium-silicon alloy pistons with
autothermic inserts (1) are graded into three sizes; to ensure correct assembly,
an arrow is stamped on the crown to show the direction of rotation
of the engine. The piston crown is concave and has four
notches to prevent interference with the valve heads.