Knuckleheadhd -

: Originally 61 cubic inches (1,000cc); increased to 74 cubic inches (1,200cc) in 1941.

The refers to the iconic overhead-valve (OHV) V-twin engine produced by Harley-Davidson between 1936 and 1947. It earned its nickname from enthusiasts because the distinct, bulbous shape of its rocker boxes resembles the knuckles of a clenched fist. It was the first production Big Twin from Harley-Davidson to feature overhead valves, a major technical leap over the previous "Flathead" models. 🛠️ Key Technical Specifications Engine Type : 45-degree V-twin, pushrod-actuated OHV. KnuckleheadHD

: Approximately 36–40 horsepower, a significant increase for its time. Transmission : Four-speed constant mesh transmission. : Originally 61 cubic inches (1,000cc); increased to

: Introduced a dry-sump system with a mechanical oil pump. 📜 Historical Significance It was the first production Big Twin from

Developed during the Great Depression and authorized for production in 1931, the Knucklehead was Harley-Davidson’s high-stakes gamble to outperform its rival, Indian Motorcycle. Despite early "teething troubles"—including oil leaks and brittle valve springs—it successfully established the template for the modern American V-twin. The Genius Engineering Of Harley-Davidson's Knucklehead