Lawrance A-3

The Lawrance A-3 or Lawrance Model A was an American twin-cylinder aircraft piston engine. Designed by Charles Lawrance in the mid-1910s the engine was produced by the Lawrance Aero Engine Company and under license by Excelsior. Weighing 200 lb (90 kg) the engine produced 28 horsepower (21 kW). A feature of this engine was the shared use of a single crankpin for both cylinders, this caused vibration as the pistons moved in the same direction.

Applications

 * Breese Penguin (flightless ground training aircraft)
 * Driggs Dart
 * Mummert Cootie
 * Shinnecock lightplane
 * Swanson SS-3
 * Waco Cootie I (monoplane)
 * Waco Cootie II (biplane)

Engines on display

 * A Lawrance A-3 is on public display at the Aerospace Museum of California