Honda RC164

The Honda RC164 is a 250 cc air-cooled DOHC inline-four racing motorcycle that Honda manufactured in 1964 to compete in the 250 cc World Championship, the last of a line of four-cylinder 250s derived from the 1959 RC160. Honda had dominated the class by 1962, but Yamaha's improving RD56 was quicker, and the inline four was at the limit of its development. Honda secretly began work on a new inline six under 24-year-old engineer Shoichiro Irimajiri in January 1964, and the RC164, lower and lighter than the earlier model, was to be used until the six was ready. Jim Redman, Luigi Taveri and Isamu Kasuya were the 1964 works riders, and Tarquinio Provini on a four-cylinder DOHC Benelli was surprisingly faster than both the Honda and the Yamaha at Montjuic.