Napier Rapier

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The Napier Rapier was a 16-cylinder H pattern air-cooled engine designed by Frank Halford and built by Napier & Son before WWII. The Rapier was the first of Napier's H cylinder engines. The rationale for the H is fairly straightforward. Rather than having an engine with fewer large cylinders, why not more small cylinders? It was believed that a H pattern engine would provide substantially more power and higher RPM's for the same frontal area as a large liquid-cooled V engine.

The H-block has a compact layout, as it essentially consists two horizontally opposed inline engines lying one on top another driving side by side crankshafts. Another advantage is that since the cylinders are opposed, the motion in one is balanced by the opposite motion in the one on the opposite side, leading to very smooth running. The Rapier suffered many of the same problems as the later Dagger and Sabre engines. The Fairey Seafox and Short S.20 were both powered by the Napier Rapier.

[edit] Specifications (Napier Rapier V)

General characteristics

  • Type: 16-cylinder air-cooled H engine
  • Bore: 89mm (3.5 in)
  • Stroke: 89mm (3.5 in)
  • Displacement: 8.83 Liters (538.8 cu in)
  • Length: 1,457mm (57.37 in)
  • Width: 549mm (21.62 in)
  • Height: 940mm (37 in)
  • Dry weight: 323kg (713 lb)

Components

  • Valvetrain: 1 inlet and 1 exhaust valve per cylinder.
  • Supercharger: yes
  • Fuel system: 1 Claudel Carburetor
  • Fuel type: 87 octane
  • Cooling system: Air-cooled

Performance

[edit] References