Harleydavidson Motor Types

The famous V-twin is an easily recognized Harley-Davidson engine.

Harley-Davidson, also known as HD, produced a number of motorcycles and engines for riding. The engine sizes are predominantly heavy class, over 750 cc, and fully capable of highway-speed cruising. The engines were produced in a number of different categories, which give the motorcycles they are used on distinctive performance traits.

The HD Traditional Motor

The classic Harley-Davidson motor incorporates a dual-cylinder design worked by a crankshaft installed on a single connection to the pistons.

The earliest motor models in HD production were the Flathead engines. Their construction began in 1929 and lasted until the mid-1970s. The motor incorporated a basic cylinder with a hole in the top for the spark plug. It was a bit above 740 cc in size and produced 22 horsepower.

Knucklehead engines began to appear in HD motorcycles by about 1936 but did not last for very long. The engine’s production was discontinued right after World War II in 1947. With a displacement size of 990 cc or 1,200 cc (there were two engine options), the horsepower output ranged from 40 to 45, respectively.

The Panhead engine appeared a year after the Knucklehead engine was discontinued, serving as a replacement model. The production cycle ran until 1965. The engine came in two sizes, 990 cc and 1,200 cc, but produced more horsepower (50 and 55 horsepower respectively) than its Knucklehead counterpart.

Shovelhead engines took over the mantle from the Panhead engine in 1966. This engine design ran until the mid-1980s as a successful product. The engine was produced in one size, 1,200 cc, and kicked out 60 horsepower.

The Big and Small V-Twins

The family of big V-twin motors, given its name due to the two cylinders aiming upward at 45-degree angles, included the Flathead, the Knucklehead, the Panhead, Twin-Cam and Evolution engines. The defining line for this grouping were engines that met or exceeded 1,000 cc in size.

The small V-twin engine family included all the alphabet engine models (those designated with a letter rather than a name), the Ironhead engine and the Evolution engine.

Twin Cam Engines

The Twin Cam engines came in two phases, the 88 and the 96 models. The engines reflected the company’s redesigned approach to big bike motors with their distinctive styling, air-cooled systems and quick reach of performance at low revolutions-per-minute levels.

The Twin Cam 88s were produced from 1999 until 2006. This engine model was 1,450 cc in size.

The Twin Cam 96 saw its introduction in 2007. The engine uses an electronic fuel injection. The size of the engine is 1,584 cc, just under 150 cc more than its Twin Cam predecessor.

The Revolution Engine

As the newest HD engine phase, the Revolution incorporated German engineering expertise in its development. Designed in a joint project with Porsche, the VR-1000 engine provides a liquid-cooled system with 60-degree-angled V-twin cylinders. The engine size measures in at 1,130 cc with a horsepower of 115.

The Revolution engine first saw public consumption in the 2002 HD motorcycle models. In 2005, the Revolution was enhanced with a larger engine measuring 1,250 cc and producing 123 horsepower. This larger engine became the standard default engine for HD Revolution motorcycles after its introduction.

For those who needed something bigger, an enhanced engine titled the VRXSE Destroyer delivered a size of 1,300 cc and produced more than 165 horsepower.