Harley-Davidson engine
Harley-Davidson engine
This video is awesome…big help! The Harley Evolution engine disassembly and engine re-assembly.
The Harley-Davidson Evolution engine
From Wikipedia, the free encyclopedia:
The Evolution engine (popularly known as Evo) is an air-cooled, 45-degree, V-twin engine manufactured from 1984 by Harley-Davidson for the company’s motorcycles. It was made in the 1,340 cc (82 cu in) displacement for Harley-Davidson Big V-twins bikes, replacing the Shovelhead engine until 2000 when the last EVO was placed in a production factory custom FXR4 (FXR2 and FXR3 were the first CVO’s). In 1999, it was replaced by the Harley-Davidson Twin Cam 88 in the Touring and Dyna model and in 2000 in the Softail models. Also available in the Sportster model beginning in 1986, it was made in the 1,100 cc (67 cu in) displacement until 1988 and is still made in the 883 cc (53.9 cu in) and 1,200 cc (73 cu in) displacements for the Harley-Davidson Sportster, replacing the ironhead Sportster engine.
Most analysts consider the Evolution to be the engine that saved the reorganized Harley-Davidson company from certain bankruptcy. Harley-Davidson’s official name for the engine was likely related to the company’s attempt to reform its image following the 1981 management buyout from previous owner American Machine and Foundry (AMF).
Though a major design advance for Harley-Davidson in many ways, the Evolution is most distinct from earlier Harley-Davidson engine designs by virtue of its reliability, oil tightness, and ability to be run hard under all kinds of circumstances for tens of thousands of miles farther than any of its predecessors. Both the heads and cylinders of the Evolution engine are made from aluminum to reduce weight compared to a cast iron design. Air cooling efficiency is improved as aluminum is a superior thermal conductor to cast iron. The blocky rocker boxes (thus becoming nicknamed “block head” which never caught on), aluminum heads and cylinders (also referred to as “jugs”) are the only part of the Evolution engine that can be said to be essential; the Big Twin and Sportster incarnations of the Evolution are significantly different.
Harley-Davidson engine