SOME years ago the SAE Ignition Research Committee expressed its need for a standardized single-cylinder engine which would take actual full-scale aviation engine cylinders into the laboratory under accurately controlled operating conditions for aviation spark-plug research. Such an engine was built by the author's company and displayed at the SAE Semi-Annual Meeting in 1937. Although this engine did meet the needs of the spark-plug manufacturers, it did not fill the needs of the petroleum industry, which was interested primarily in lubricating oil and fuel tests.
A volunteer group, organized at the 1937 SAE Semi-Annual Meeting, first listed the features which such a design must include, and then a small design subcommittee was formed to study and coordinate the requirements. Five complete designs were made before a combination was developed which appeared to meet all requirements in a satisfactory manner.
The single-cylinder crankcase design was laid out to provide for the Wright Cyclone air-cooled cylinder, 6⅛ x 6⅞ in. bore and stroke, the largest in general use at the time.
A detailed description of the C.U.E. engine design and construction comprises the major part of Mr. Pope's presentation, covering such features as: the balancing system; main roller bearings; smooth-walled crank chamber; lubrication; crankcase construction; temperature control; crankcase seal; accessory drives; crankshaft; connecting rod; speed; spark indicator; flywheel; reverse rotation; dynamometer coupling; and fuel injection system.