Knucklehead
Encyclopedia
The knucklehead was a Harley-Davidson
motorcycle
engine
, so named because of the distinct shape of the rocker boxes. The engine is a two cylinder, 45 degree, pushrod actuated overhead valve V-twin engine with two valves per cylinder. It was the third basic type of V-Twin engine used by Harley-Davidson, replacing the Flathead-engined VL model in 1936 as HD's top-of-the-line model. The engine was manufactured until 1947 and was replaced by the Panhead
engine in 1948.The Knucklehead-engined models were originally referred to as "OHVs" by enthusiasts of the time; the nickname "Knucklehead" arose from the California chopper culture of the late 1960s.
As the design of Harley-Davidson engines has evolved through the years, the distinctive shape of the valve covers has allowed Harley enthusiasts to classify an engine simply by looking at the shape of the cover. A knucklehead engine has round knobs on the cover resembling knuckles that give the knucklehead its name.
Harley-Davidson
Harley-Davidson , often abbreviated H-D or Harley, is an American motorcycle manufacturer. Founded in Milwaukee, Wisconsin, during the first decade of the 20th century, it was one of two major American motorcycle manufacturers to survive the Great Depression...
motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
engine
Engine
An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...
, so named because of the distinct shape of the rocker boxes. The engine is a two cylinder, 45 degree, pushrod actuated overhead valve V-twin engine with two valves per cylinder. It was the third basic type of V-Twin engine used by Harley-Davidson, replacing the Flathead-engined VL model in 1936 as HD's top-of-the-line model. The engine was manufactured until 1947 and was replaced by the Panhead
Panhead
The panhead was a Harley-Davidson motorcycle engine, so nicknamed because of the distinct shape of the rocker covers. The engine is a two-cylinder, two-valve-per-cylinder, pushrod V-twin...
engine in 1948.The Knucklehead-engined models were originally referred to as "OHVs" by enthusiasts of the time; the nickname "Knucklehead" arose from the California chopper culture of the late 1960s.
As the design of Harley-Davidson engines has evolved through the years, the distinctive shape of the valve covers has allowed Harley enthusiasts to classify an engine simply by looking at the shape of the cover. A knucklehead engine has round knobs on the cover resembling knuckles that give the knucklehead its name.