This is an axial or barrel engine, which has multiple cylinders arranged around and parallel to a central shaft, like the chambers in the cylinder of a revolver. The piston thrust is converted to rotary motion by a swashplate, wobble-plate or Z-crank mechanism.
16cc, single cylinder, side valve motor links to the very earliest days of the use of IC engines in racing boats, as it was built by F G Arkell
Scale model vignette by Satoshi Araki. #rusted #diorama
Alcohol powered engine that was made from a few leftover materials. The displacement is approximately .05 cu. in. and the base is about two inches square.