• The piston in the cylinder of the cylinder block moves reciprocally while transmitting pressure to the piston pin and connecting rod when the air-fuel mixture combusts.
Piston ring
• The piston ring consists of the compression ring (top ring, second ring) and the oil ring, and has the following functions.
― The compression ring prevents leakage of pressure in the cylinder from the piston circumference.
― The oil ring clears off extra engine oil adhered to the cylinder wall.
• The piston ring transmits piston heat to the cylinder wall to cool the piston.
Piston pin
• The reciprocating movement of the piston is transmitted to the connecting rod by the connection of the piston pin to connecting rod.
Construction
Piston
• The piston is made of aluminum alloy with superior high-temperature strength and excellent thermal conductivity.
• The piston has a cavity on the top surface. As a result, the initial combustion flame is prevented from hitting the top surface of the piston to reduce cooling loss.
amxuun00001786
am3uun00001853
• The sliding resistance and the part mass have been minimized by reducing the surface area of the piston skirt and reducing the thickness.
• An offset piston has been adopted in which the center of the piston pin has been offset from the piston center. As a result, piston slap is suppressed.
amxuun00001787
Piston ring
• A barrel-face ring for the top ring and a taper under cut ring for the second ring have been adopted.
• A three-piece oil ring consisting of a side rail and spacer have been adopted for the oil ring.
• The tracking capability to the cylinder wall has been improved by reducing the thickness of the piston ring. As a result, a low-tension piston ring has been implemented without increasing the engine oil consumption, and the sliding resistance has been reduced during reciprocating movement.