Nelson H-44

The Nelson H-44 is an American single ignition, four-cylinder, horizontally opposed, direct drive, two-stroke aircraft engine that was developed by the Nelson Engine Company for use in motorgliders.

Design and development
The H-44 was designed 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 engine was not certified. Under the CAR 5 regulations then in place in the US 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.

Operational history
Employed in the Dragonfly the H-44 proved underpowered, which led to the design of the H-49 version. The engine family was not a success and few were produced.

Variants

 * H-44
 * Original design with a 2.25 in bore and 2.75 in stroke, producing 25 hp at 3900 rpm.


 * H-49
 * Upgraded design with E-225 cylinders giving a 2.375 in bore and 2.75 in stroke, producing 28 hp at 4000 rpm.

Applications

 * Bowlus/Nelson Dragonfly