Lycoming XH-2470-7, H-24 Engine

Type: Reciprocating, 24 cylinders, H-type, Liquid-cooled

Power rating: 1,491 kW (2,000 hp) at 3,100 rpm

Displacement: 40.5 L (2,470 cu in)

Bore and Stroke: 133 mm (5.3 in.) x 121 mm (4.8 in.)

Weight: 1,281 kg (2,824 lb)

In 1939, the Air Corps identified a need for flat, H-type engines for installation in bomber wings. Lycoming had already begun Navy studies for the 24-cylinder H-2470 engine, and the Army arranged to buy two engines under that contract. In 1942, the Navy, proposing the H-2470 for the Curtiss F14C fighter, sent a letter of intent ordering 100 engines, 50 of which were for the Army. A new Lycoming factory was set up in Toledo, Ohio, exclusively for H-2470 production. However, before the factory went into production, the Navy decided that it would not be available for the war and canceled its contract.

With limited Army support, the engine was flight tested in the Vultee XP-54. But again it was clear that the H-2470 could not be ready for use in the war, and the Army dropped the project before the end of 1943. This XH-2470-7 artifact was equipped with a dual rotation propeller shaft.