Arrival

Dissassembly

Mechanical

Body & Paint

Finish

Harley-Davidson, Inc. is an American motorcycle manufacturer, founded in Milwaukee, Wisconsin in 1903.  One of two major American motorcycle manufacturers to survive the Great Depression (along with Indian), the company has survived numerous ownership arrangements, subsidiary arrangements (e.g., Aermacchi 1974-1978 and Buell 1987-2009), periods of poor economic health and product quality, as well as intense global competition, to become one of the world’s largest motorcycle manufacturers and an iconic brand widely known for its loyal following. There are owner clubs and events worldwide as well as a company-sponsored brand-focused museum.

In 1936, the 61E and 61EL models with the “Knucklehead” OHV engines were introduced. Valvetrain problems in early Knucklehead engines required a redesign halfway through its first year of production and retrofitting of the new valvetrain on earlier engines.

The knucklehead is a retronym used by enthusiasts to refer to 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 and in Harley’s official literature; the nickname 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. The knucklehead engine valve covers have contours resembling knuckles on a person’s fist that give the knucklehead its name.

By 1937, all Harley-Davidson flathead engines were equipped with dry-sump oil recirculation systems similar to the one introduced in the “Knucklehead” OHV engine. The revised 74-cubic-inch (1,212 cc ) V and VL models were renamed U and UL, the 80-cubic-inch (1,300 cc³) VH and VLH to be renamed UH and ULH, and the 45-cubic-inch (740 cc³) R to be renamed W.

In 1941, the 74-cubic-inch (1,210 cm³) “Knucklehead” was introduced as the F and the FL. The 80-cubic-inch (1,300 cc³) flathead UH and ULH models were discontinued after 1941, while the 74 inch (1210 cm³) U & UL flathead models were produced up to 1948.

https://en.wikipedia.org/wiki/Harley-Davidson_Knucklehead_engine