The hot cylinder, hot cylinder liner, power cylinder liner, and power cylinder are designed as a whole, which is easy to assemble. The cylinder liner is a fin-shaped heat dissipation structure. The alcohol lamp, bracket and bottom plate are designed in one piece. Both ends of the bracket are equipped with a large alloy flywheel and a small flywheel; high-precision imported bearings are used between the flywheel shaft and the bracket. This model is in the form of separate parts, exercises hands-on ability, and the all-metal structure can be repeatedly disassembled and assembled.