This cylindrical rotary engine was built by Alphonse Vassallo, of California, in 1973. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo.) Al experimented with many new “proof-of-concept” engine designs. Internally, this engine resembles a positive-flow (vane type) rotary pump similar in design to a water pump. Al designed a spring-loaded, four-vane rotor, which he placed within a highly modified combustion chamber. Then he carefully positioned the carburetor and exhaust manifold and strategically installed the spark plug for proper ignition The ignition points and adjustable timer assembly are mounted on the back of the engine. Although never completed, it was designed to burn gasoline with oil mixed in for lubrication. The engine is 7″-long, 5″-wide, 3.5″-high, and weighs 5 lbs.