With a vacuum engine the power stroke comes from the air inside contracting while cooling. This is the opposite of most engines which use the expanding hot air inside the engine to drive the engine. In order for the vacuum engine to work the flame is external; a sliding valve opens and the piston draws in the flame. The flame can be seen briefly being pulled into the engine. The valve closes. The cylinder has a large heatsink around the outside. At this point the air inside starts to cool and the piston is pulled back due to the vacuum. The whole cycle then repeats.
This engine comes in kit form. It is not overly complex but can't be described as simple. I would suggest it is better suited towards a mechanically minded teenager or adult.
The instructions DO NOT COME IN ENGLISH. However the instructions in English can be found here English instructions
- Real external combustion engine with external heat source
- The engine can be removed quite easily from the car
- Takes about 2 hours to assemble
- Die-cast aluminum design
- Fan to cool the engine
- methylated spirits burner
- Japanese manufactured
- Japanese instructions