Crate engines are replacement engines shipped in crates; Harley-Davidson does not manufacture motorcycles with crate engines. Harley-Davidson sells crate engines for most of its motorcycles and offers many of its engine types in crate kits, including New Revolution, Twin Cam and Evolution.
Most Harley-Davidson crate engines are available in a variety of configurations to fit into most motorcycle frame styles, including VRSC, Dyna, Softail, Touring and Trike models. The company recommends that owners consult their local dealers for specific details and crate engine recommendations. Crate engines replace old or failing engines or provide significant upgrades in power.
The benefit of crate engines is that they arrive fully assembled in the crate, ready to unpack and bolt directly into the existing frame. One potential downside is that they can be very expensive. The newest model of Harley-Davidson crate engine, as of 2015, is the Screamin' Eagle 120ST, which fits any Harley Touring chasis. It upgrades the engine to 1966 cubic centimeters, 106 horsepower and 117 feet pound of torque.
The crate-engine concept started with the hot-rod car sector, where hot rodders could buy the engines they wanted, bolt them in, and go. The concept spread to Harley enthusiasts and has become extremely popular.