Constantine, Arthur
Name/Title
Constantine, ArthurTags
Design & Engineering, Ambassadors & IndustryDescription
- Engineer and designer for Harley-Davidson, Excelsior-Henderson, and Indian motorcycle companies - Designer of two of the most innovative motorcycles of the early 20th century: the 1925 Excelsior Super-X and the 1929 Henderson KJ Streamline Born in 1891, Arthur “Connie” Constantine was one of the preeminent motorcycle engineers of the 1920s. A lifelong motorcyclist and engineer, he was initially employed by the Buick Division of General Motors until 1920, when he was offered the position of assistant chief engineer at The Harley-Davidson Motor Company. His resume there included work on many chassis and engine development projects, including Harley-Davidson’s potent eight-valve racing engine. While in Harley-Davidson’s employ, Constantine worked on an unauthorized design project for a new mid-sized V-twin engine that would compete against rival Indian’s famous Scout. Once revealed, his design was condemned by Harley leadership as a “waste of valuable company time,” however, and as a result, Constantine resigned from Harley-Davidson in 1924. With his innovative design in hand, Constantine approached Excelsior Motor Manufacturing Company with his concept for a unit-construction motor, one in which the engine and transmission shared the same crankcase. Unveiled in 1925 as the 45-cubic-inch Excelsior Super-X, the new motorcycle became an astounding success both in the showroom and on the racetrack. Excelsior also owned and operated Henderson Motorcycle Company at the same time, and Constantine’s contributions to that brand were equally revolutionary. Following the successful debut of the Super-X, Constantine was next enlisted to review the famous Henderson DeLuxe. He soon came to the conclusion that a radical redesign was the only course of action to improve that machine. The result was his masterpiece, the Henderson KJ Streamline, unveiled in March of 1929. The KJ Streamline boasted no less than 57 new features and developed 40 horsepower at 4,000 rpm. The inline-four motor design utilized an overhead intake valve arrangement and incorporated a five-bearing crankshaft, improved pressurized oiling and a down-draft intake manifold. The redesigned chassis featured an even lower saddle, and the outboard-mounted fuel tanks were shaped in a modern, streamlined style, lending the motorcycle its distinctive name. Not only did it look great, but the Henderson KJ Streamline was guaranteed to hit 100 mph, too. In the late 1940s, Indian Motorcycle Company retained Constantine as a consultant on the development of the new Indian Arrow and Warrior models. He was subsequently hired as chief engineer and vice president of Indian, giving him the unique status of having served significant roles at the three biggest and most important motorcycle manufacturers of the early 20th century. Constantine died in 1973.Category
Class of 1998