M.Dusing German & Austro-Hungarian Aero Engines of WWI. Vol.2 (A Centennial Perspective on Great War Airplanes 65)

Delfosse Motorenfabrik GmbH, Ko In

Three-Cylinder 30/24 hp Fan-Type Aircraft Engine (Type 1)

  For his first monoplane, Delfosse first developed a fan-shaped 3-cylinder engine in 1908/09. This engine was purely air-cooled and designed in the way it was common at that time. The valves were controlled via push rods.
  The engine was equipped with a H.T. magneto, but also a version with a 6 volt accumulator is known.
  The fan-shaped cylinders of this engine are offset by 72 degrees, so that magneto ignition could be used. The bore was 110 mm with 120 mm stroke, speed 1200-1500. 24/30 hp, minimum power 24 hp with 110 kg traction.
  Other features were: Special metal cylinders, very large valve chambers and chrome nickel crankshaft.
  This engine was practically tested together with the flying machine of Lieutenant Lanyi. The built-in Delfosse engine (stroke 120 mm, bore 110 mm) produced 30 hp at 1400 revolutions. The whole apparatus weighed 205 kg without pilot.
  The flight tests carried out were satisfactory, but longer flights could not be undertaken due to unreliability of the engine.