HISTORY OF THE HARLEY ENGINE
Harley-Davidson introduces the EL, an overhead valve, 61 cubic inch powered bike. With increased horsepower and bold styling changes, the motorcycle quickly earns the nickname of "Knucklehead," due to the shape of its rocker boxes. The same year, the Motor Company introduces a 80 cubic inch side valve engine.
Harley-Davidson unveils the 1340cc V²® Evolution® engine on five models including the all-new Softail®. The result of seven years of development, the Evolution engine produces more power at every speed, runs cooler, cleaner and is oil-tight. Also witnessed is the debut of the Softail design and its trend-setting method of "hiding" the motorcycle's rear shock absorbers.