Troublesome Gallery

Hawker Hector with Napier Dagger III engine

A detail of a Hawker Hector focussing on the Napier Dagger III H-24 air-cooled piston Engine. Developing 805hp the Dagger was the next step for D. Napier and Sons toward the ultimate British piston Engine of World War II, the Napier Sabre. Unlike the later Sabre the fast running Dagger was air-cooled and used conventional poppet-valves, rather than the troublesome sleeve-valves of the Sabre and large Bristol radial Engines. ( Engines of H-configuration had two crankshafts side-by side, both driving the same reduction gearbox to give one output. In some contemporary H- Engines, such as the Fairey Prince, the crankshafts each drove one half of a contra-rotating propeller and could be individually shut done.) Date: 1970s

© The Peter Butt Aviation Collection / Mary Evans