Harley-Davidson introduced the Panhead engine in 1948.
The Panhead succeeded the Knucklehead and received its nickname from the pan-like shape of its rocker covers. It was an overhead-valve V-twin designed for Harley-Davidson’s large motorcycles. Early Panheads were available in 61- and 74-cubic-inch forms.
Compared with the Knucklehead, the Panhead incorporated important changes intended to improve durability and heat management, including aluminum cylinder heads. The engine was used through the late 1950s and into the early 1960s, depending on the specific model and displacement.
The Panhead name belongs to an engine generation, not one single motorcycle model. It is often confused with “Shovelhead,” which replaced it in Harley-Davidson’s big-twin range beginning in 1966. The sequence of nicknames provides a useful outline of postwar Harley-Davidson engine development.