Lawrance A-3

Twin-cylinder aircraft piston engine

A-3/Model A

Lawrance Model A engine on display at the Aviation Hall of Fame and Museum of New Jersey
Type	Piston aero engine
National origin	United States
Manufacturer	Lawrance Aero Engine Company
Designer	Charles Lawrance
First run	c.1916
Produced	c.450

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).^[1] 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.^[1]

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

Specifications

Data from Gunston.^[1]

General characteristics

Type: Two-cylinder, air-cooled horizontally opposed piston aircraft engine
Dry weight: 200 lb (91 kg)

Components

Cooling system: Air-cooled

Performance

Power output: 28 hp (21 kW) at 1400 rpm

References

Wikimedia Commons has media related to Lawrance A-3.

Notes

^ ^a ^b ^c Gunston 1989, p. 92.

Bibliography

Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

Wright and Lawrance aircraft engines

Wright inline engines

Lawrance radials

Wright radials

Whirlwind family	J-3 J-4 J-5 J-6-5 J-6-7 J-6-9 R-540 R-760 R-790 R-975 R-1510 R-1670
Cyclone family	Cyclone 7 Cyclone 9 Cyclone Twin Cyclone Duplex-Cyclone Cyclone 22 R-1300 R-1750 R-1820 R-2600 R-3350 R-4090
Others	L-3 Gale R-1200 R-2160 Tornado