Connecting rods with pistons assemblies — general information

The connecting rods are made from steel forgings. The top lug is equipped with a bronze bushing. The lower one is collapsible and a three-layer metal insert is inserted into it. The correct relative position of the connecting rod and the lower part of the hole is indicated by punching on the sides (see designation B in fig. Mounting reamer of connecting rod and piston), the matching of the connecting rod assembly and the cylinder is ensured by the number of punches on the surface of the connecting rod and the lower lug. The connecting rods are divided into groups by weight of 75 g and checked for parallelism of both lugs.

Pistons are machined light alloy castings (Al, Si, Cu, Ni, Mg), the friction surface of which is graphitized in order to reduce the gap. This has a positive effect when starting a cold engine and also leads to a smoother and quieter engine operation. Three grooves on each piston contain two sealing rings and one wear ring. On all rings, the top is indicated "TOR". The arrow on the bottom of the piston must always point to the belt drive during assembly.