Velie M-5, Radial 5 Engine

Type: Reciprocating, 5 cylinders, radial, air cooled

Power rating: 41 kW (55 hp) at 1,750 rpm

Displacement: 4.1 L (250 cu in.)

Bore and Stroke: 105 mm (4.125 in.) x 95.3 mm (3.75 in.)

Weight: 108.9 kg (240 lb)

The Mono Aircraft Corporation and the Velie Motors Corporation of Moline, Illinois started in the aircraft engine field by building the Model M-5, certificated in 1928. The Velie M-5 was a close copy of the Detroit Aircraft Engine Corporation Aircat built in 1926. Because of dissatisfaction with the Aircat’s reliability and delivery problems, Mono Aircraft tasked the Velie automobile firm to build the M-5. Most of the patented features of the Aircat were declared infringed following litigation, and Velie had to pay damages.

Following deaths in the Velie family, the firm was first incorporated into the John Deere tractor business, and later production conducted by the Lambert Aircraft Engine Corporation, a subsidiary of the Allied Aviation Corporation. Because only Mono used this engine, Lambert was discontinued when the Monocoupe became obsolete.

The M-5 powered the Monocoupe, Monocoupe 113, and Monoprep 218.