In 1944, many of the components used in the Morton M5 radial engine and M-4 inline were to be incorporated into this newly proposed M-42 flathead engine. The drawings for the M-42 were completed, but the engine never made it to production. From only one drawing that survived the Morton Company, Jim Hawk of Oklahoma fabricated the wooden patterns, produced his own aluminum castings, and machined the components to complete this running model in 2006. It burns gasoline on spark ignition and will turn a 14-6 propeller in excess of 6,500 RPM. The engine is 9″-long, 5″-wide, and 5″-high.

Flathead engines were commonly called side-valve engines because the valves are positioned in the block alongside the cylinders. Overhead valves are positioned in the head above the combustion chamber. Since overhead valves were not developed until the 1950’s, the heads for the side-valve engines were flat, resulting in the name “flathead.”

Exhibit added: May 1, 2008 - Last modified: March 15, 2023

Presented by The Joe Martin Foundation for Exceptional Craftsmanship