In order to confirm cylinder deactivation schemes with preferable dynamic performances of internal combustion engine motion mechanisms, the flexible dynamic model of a V8 diesel engine was established, which coupled mechanisms such as cranktrain, timing-gears, and valvetrain. The dynamic models were validated by experimental data. Motion mechanisms dynamic simulations were conducted for single cylinder deactivation. The results revealed that angular displacement amplitude of crankshaft obviously increased when single cylinder activated, which mainly consisted of low orders rolling vibration, while the change to camshaft was negligible. Motion characteristics of valvetrain were deteriorated and mechanical load increased. Deactivated cylinders which were neighboring to the single or double crunodes positions of crankshaft, behaved better dynamic performances under high speed and low engine loads. 