In the previous reports^<(1)-(3)>, the multi-media contents which support understandings of the operation principle of internal combustion engines were developed, and these contents were practiced in the machine practical training subject, and the learning effect was examined by the short tests and questionnaire. In this report, to explain the cycle of Otto engine, above-mentioned contents have been improved. This new contents installed the pointers that synchronize with the movement of the piston on the diagrams of PV, VS, TP and TS. The learners can operate these contents directly in the e-learning system. The learners can move the piston and they can confirm the state of this engine about temperature, pressure, volume, and entropy by synchronized pointer on the diagrams.
