This Four-Cylinder Engine Won The Indy 500 27 Times Between 1935 And 1976

The four-cylinder Offenhauser engine, known as the Offy, powered Indy 500 winners 27 times between 1935 and 1976. Its origins lie with Miller and Leo Goossen, later branded by Offenhauser. It began at 151 cubic inches and grew to 270 cubic inches by 1937 as racing rules evolved. The DOHC design and a single-unit block eliminating head gaskets were hallmarks of its rugged, high-rev design. Turbocharged Offenhauser engines arrived in 1966, with 625 horsepower by 1968 and roughly 1,100 horsepower in 1972 qualifying-era cars. Offenhauser’s dominance culminated with wins through 1976, marking the end of an era when four-cylinders won Indy; the technology and Penske’s team history are part of the broader racing legacy.