Napier Dagger

The Napier Dagger was a 24-cylinder aircraft engine from Napier & Son

The management of Napier & Son provides 1929 the freelance design engineer Frank Halford. Halford designed a H engine with lots of small air-cooled cylinders and extremely high speeds, which was different from all previous developments in Napier. This referred to as Napier Rapier engine had 16 cylinders, four each in series, and two crankshafts, which drives the centrally arranged propeller shaft via a gear.

The Rapier was the forerunner of the Dagger, with 24 slightly larger cylinders in H arrangement. The engine capacity was 16.84 L. The first versions of 1934 delivered 635 hp. Later versions of 1936 delivered at 4,000 rpm already 950 hp. The built- in, for example, Handley Page Hampden Dagger VIII ensured in 2,600 m altitude 1,000 hp and reached the former " magic limit " of a horsepower per cubic inch of displacement.

The Dagger was a complicated machine. There was at that time much simpler engines built with the same amount of power. Furthermore, the Dagger developed a lot of noise and was quite unreliable.

Specifications

Napier Dagger

  • Type: air-cooled, turbocharged 24-cylinder aircraft engine H-type
  • Capacity: 16.84 l
  • Bore: 97 mm
  • Stroke 95 mm
  • Power: 635 hp - 1000 hp ( at 4,000 rpm )

Application

  • Handley Page Hereford
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