The R-755 was first run in 1933 and was still in production in the 1970s. With a bore and stroke of 5.25 inches × 5 inches. The displacement was 757 cu in (12.4 L), power ranged from 200 hp to 350 hp. The R-755 features steel cylinders with aluminum-alloy cylinder heads. An R-755E variant was developed for use in helicopters.