 During World War I the Lawrance Aero Engine Company of New York City produced the crude opposed twins that powered the Penguin trainers, and the Lawrance L-1 60 hp Y-type radial.After the end of World War I, the Lawrance engineers worked with both the Army and the Navy in developing their L-1 onto a nine-cylinder radial engine, which became the 200 hp Model J-1.It was the best American air-cooled engine at the time and passed its 50-hour test in 1922.