Charles Lawrance started designs for an air-cooled engine in 1915, designing his first 149 kW (200 hp) J-1 for a 1921 Navy contract. The Navy wanted a better engine for use on aircraft carriers, needing a compact lightweight engine not plagued with water leakage problems. After Lawrance’s company was absorbed by Wright Aeronautical in 1923, the J-1 progressed through stages, as the Whirlwind J-3, J-4, J-5, and J-6 series. Used in Lindbergh’s Spirit of St. Louis, the J-5 was the most famous.

The Wright J-4 incorporated improvements based on service with preceding models. J-4 engines powered such aircraft as the Fairchild FC-1 and FC-2, Fokker Universal, Laird Commercial LC-B200, Stearman C2B and C3B, and Stinson Detroiter SB-1.

This Wright J-4 engine was the first type of engine that Northwest Airlines used in its original Contract Air Mail and Passenger run between Minneapolis, Minnesota, and Chicago, Illinois, in October 1926 with a Stinson Detroiter four-place biplane.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date April 2, 1926 Country of Origin United States of America Type PROPULSION-Reciprocating & Rotary Designer Lawrance Aero Engine Corp
 Manufacturer Wright Aeronautical
 Physical Description Type: Reciprocating, 9 cylinders, radial, air cooled Power rating: 149 kW (200 hp) at 1,800 rpm Displacement: 12.9 L (788 cu in.) Bore and Stroke: 114 mm (4.5 in.) x 140 mm (5.5 in.) Weight: 218 kg (480 lb) Dimensions Diameter 111.8 cm (44.0 in.), Length 86.4 cm (34.0 in.)
 Inventory Number A19650270000 Credit Line Gift of Northwest Orient Airlines Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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