Design and development The Aquila was developed two years after the somewhat larger Perseus, both being sleeve valve designs. The primary difference was in size, the Perseus being based on the cylinder used in the Mercury engine, while the Aquila used a new and smaller sized cylinder. The result was a reduction in displacement from 1520 to 950 cubic inches (24.9 to 15.6 L).
Design and development The Aquila. was developed two years after the somewhat larger Perseus, both be?ing sleeve valve designs The primary difference was in size, the Perseus being based on the cylinder used in the !Mercury engine, while the A.quila used a new and smaller sized cylinder The result was a reduction in displacement from 1520 to 950 cubic i.nches (24.9 to 15.6 L)