1-5 Cam shaft The camshaft is manufactured by knockdown system. The cam lobe and the com journal are pressed in a hollow carbon steel tube. The cam lobe is welded. By adopting a special profile for the cam, together with improving inhalation efficiency, quiet operation can be expected. The valve lift is optimized and the intake-air volume is heightened in order to improve combustion efficiency. 1 Cam journal Hollow carbon steel tube Cam lobe Rotative direction Exhaust Intake