edit ] The Big V-Twins F-head , also known as JD, pocket valve and IOE (intake over exhaust), 1914-29 (1,000 ccm), and 1922-29 (1,200 ccm) Flathead , 1930-1948 (1,200 ccm) and 1935-41 (1,300 ccm). Knucklehead , 1936-47 61 cubic inches (1,000 ccm), and 1941-47 74 cubic inches (1,200 ccm) Panhead ,