HARLEY-DAVIDSON V-TWIN * 1909 - 1911 and *1911 - 1929 F HEAD
A V-Twin is a two-cylinder engine layout forming a "V". The
pistons are aligned so that they appear to be a "V" when viewed along the crankshaft. The V-Twin configuration reduces
overall engine length and weight compared to an equivalent straight engine (the straight engine or in-line engine is an
engine with cylinders aligned in a row), allowing for maximum torque and power for any given displacement. V-Twins on a Harley-Davidson
motorcycles are mounted in a parallel position which is well adapted to its transmission shafting, but has the disadvantage
of causing a torque reaction that tends to lean the motorcycle on one side. The first V-Twin was introduced in 1903,
with two and three-speed gearboxes.
Harley-Davidson Police Bikes
The First Knuckleheads
HARLEY-DAVIDSON
FLATHEAD * 1929 - 1935 and a HARLEY-DAVIDSON KNUCKLEHEAD * 1936 - 1947
The most obvious configuration for a Twin is a 90 degree angle, but
Harley-Davidson Twins have always been 45 degrees. A Harley has two pistons, and the crankshaft has only one pin and both
pistons are connected to it. A normal two cylinder engine fires one piston on the first revolution of the crankshaft, and
the second one on the second revolution, resulting in a smooth running engine. This is a common design with two crank
pins for the connecting rods which connect to the pistons. A Harley has two pistons, but the crankshaft has only one pin connecting
to both pistons, so they fire almost at the same time instead of at different intervals. This configuration results in the
unique throaty sound of the Harley-Davidson engine.
The Knucklehead Era
Chopped Harleys-Where It All Began-1946-1959
Harley 1%ers vs. The Nicest People - The 1950s
Harley-Davidson Military Bikes
