In the stroke range of piston rings, it keep confining the hardness of the liner within narrow limits to strengthen the endurance and to avoid irregular wear, while others fluctuate in wide range of hardness.

Homogeneous Casting Structure and few cavities but to a special mothod for more cooling Effect and durability, while others are made by means of general casting method it may cause several defects.

Theoriginal right-angled edge of each cooling disk of the barrel's modified to the rounded edge to maximize the cooling efficiency by air cooling fan of the engine. It is special features distingushing the Cylinder from others.
The efficiency rate was simulated with the CAE based on fluid mechanics by the technical research center and showed 6.3% of improvement in air cooling efficiency.

Dimension on most of important points was strictly controlled and measured by CMM which is directly related with the performance and the endurance of the Cylinder and Engine.