Full-scale you use the vacuum state! Assembly kit of a detachable engine unit. Engine, a type of external combustion engine with a heat source to external. In the cylinder, heat sucked is cooled, it is moving the piston by creating a vacuum state. Opening and closing of the valve is integrated with the piston by a crank mechanism. The addition of the flywheel effect further, it is possible to obtain the stable rotation. I can see the basis of thermodynamics. Full-scale external combustion engine assembly kit with out the [Features] heat source. Engine detachable unitized. The approximately two-hour special tool [product] configuration and assembly kit (parts, plus driver) does not require assembly time