Nelson H-44 / H-49
The H-44 was designed by Ted Nelson in the period following the Second World War and a specially designed motor glider was created by Hawley Bowlus to utilize the engine, the Bowlus/Nelson Dragonfly.
The Nelson H-44 is a single ignition, four-cylinder, horizontally opposed, direct drive, two-stroke aircraft engine. The engine was not certified. Under the CAR 5 regulations then in place in the USA for gliders, a certified auxiliary power glider could be flown with a non-certified engine and propeller. The engine is instead described on the Dragonfly type certificate.
The four-cylinder engine runs on a 12:1 mixture of 80 octane gasoline and SAE 30 oil. It is equipped with a single Carter WA1 carburetor and a recoil starter.
Employed in the Dragonfly the H-44 proved underpowered, which lead to the design of the H-49 version. The engine family was not a success and few were produced.
Original design with a 2.25 in (57 mm) bore and 2.75 in (70 mm) stroke, producing 25 hp (19 kW) at 3900 rpm.
Upgraded design with E-225 cylinders giving a 2.375 in (60 mm) bore and 2.75 in (70 mm) stroke, producing 28 hp (21 kW) at 4000 rpm.
Type: Four-cylinder, two-stroke, single-ignition aircraft engine
Bore: 2.25 in (57 mm)
Stroke: 2.75 in (70 mm)
Displacement: 44 cubic inches
Dry weight: 40 lb (18 kg)
Designer: Ted Nelson
Fuel system: Carter WA1 carburetor
Fuel type: 80 octane gasoline
Oil system: premixed oil in fuel, SAE 30 oil mixed at 12:1 fuel to oil
Cooling system: air