1949 VELOCETTE MAC IS A TOP-SELLER
The Velocette MAC debuted in 1933. It had an air-cooled OHV 350cc single cylinder engine that was capable of hustling the 280-pound MAC to 75mph. It was developed out of the 250cc Velocette MOV by lengthening its stroke for the 1934 model year, and the new machine was called MAC. It turned out to be Velocette’s top seller for many years. It was not only popular, but much cheaper to produce than the OHC KSS, which required meticulous hand assembly. 1939 marked the beginning of Britain’s involvement in World War II, ending civilian production. This brought military orders for the MAC, now with a (WD) after the name, signifying Britain’s War Department. Civilian production resumed in 1946 and the postwar MACs now featured telescopic forks, replacing the old girders. MAC production continued through 1960.
1949 VELOCETTE MAC ENGINE
Velocette was an early pioneer of advanced overhead cam (OHC) engine designs. Designed by Percy & Eugene Goodman (sons of the owner of Velocette), all OHCs were designated K-series. The “K” was for “kam”, the German word for “cam”, meaning overhead cam. OHC designs in the 1920s were almost unheard of, as most 4-stroke engines were side-valve (flathead) designs, and only a few were OHV. These advanced engines helped a small manufacturer like Velocette stand out against the giants of the industry. The earliest K-series bikes were race machines whose development led to street bikes, the first being the KSS. However, that overhead cam was driven by an exotic shaft-drive system with bevel gears at both ends, and it was slow, difficult and expensive to build, requiring hand-assembly by highly-skilled craftsmen. This slowed production to a crawl and drove up costs. In the end, the long-term answer was the abandonment of the K-series OHC bikes in favor of the simpler, cheaper-to-build OHV M-series bikes, which ended up being Velocette’s biggest sellers.