The Continental R-670 (factory designation W-670) is a seven cylinder four-cycle radial aircraft engine produced by Continental has a displacement of 668 cubic inches (11 liters) and has a dry weight of 465 lb (211 kg). The engine’s horsepower varied from 210 to 240 at 2,200 rpm. The engine was the successor to Continental’s first radial engine, the 170hp Continental A-70. This engine was used on many aircraft in the 1930s and 1940s. The R-670 was widely used in the PT-17 Stearman, a primary training aircraft of the US military.