Pistons And Connecting Rods
The pistons are cast and are made of a light metal alloy. The piston mantle is coated with graphite. The first groove is hard anodized to minimize wear.
The piston is equipped with two compression rings and a three piece oil ring.
The connecting rods are forged. The contact surface between the bearing cap and the connecting rod is treated. Guide pins contribute to good alignment. The connecting rod bearings are aluminum bearings. The bearings are lead free.
The piston transfers the compressive force of the ignited fuel/air mixture to the crankshaft via the connecting rod. The piston rings form a seal so that the fuel/air mixture does not force its way down past the piston. The top ring ensures a seal between the piston and the cylinder. The second ring also seals and scrapes away any oil during the downward movement of the piston. The third ring makes sure the oil drains via the drain hole.
The pistons are oil-cooled. This is necessitated by the short distance between the piston head and the top piston ring.