Building on the success of the limited-production S500, in 1964 Honda launched the S600. Initially only available as a roadster, a fastback coupe would soon follow. The S600 was powered by a 57-horsepower, 606-cubic-centimeter dual-overhead-cam inline four-cylinder engine fueled by four Keihin carburetors, and capable of revving to an impressive 9,500 rpm redline. The engine was backed by a four-speed manual gearbox which sent power through a hypoid differential to the rear wheels via chain final drives for each wheel.