Indian Motocycle Manufacturing Company color options in 1934. Models of that era had Indian's famous war bonnet logo on the gas tank. Indian's huge Springfield factory was known as the Wigwam, and native American imagery was much used in advertising. In 1940, Indian sold nearly as many motorcycles as its major rival, Harley-Davidson. During this time, Indian also manufactured other products such as aircraft engines, bicycles, boat motors and air conditioners. The Indian Scout was built from 1920 through 1949. It rivaled the Chief as Indian's most important model. The Scout was introduced for 1920. Designed by Charles B. Franklin, the Scout had its
Harley-Davidson Evolution engine until 1988 and is still made in the and 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). 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