In the early ‘80s Harley-Davidson was struggling to compete with the imports and the damage done by the AMC ownership. Years of less than stellar reliability and performance needed to be overcome for the company to remain a going concern. As the company looked at rebuilding its reputation and place in the market a decision was made to develop a new engine. The Evolution engine was born.
Harley had to overcome the stigma of the leaking engine, known for marking their spots the Shovelhead motor let you know where it lived. This was partially because of the use of cast iron cylinders and aluminum heads. The metals expanded and contracted at different rates the during heating and cooling cycles. This caused stress and wear on seals and thus leaks.
Using the same aluminum composition as used in airplane cylinders. This composition was designed for strength under high heat, which fit the need of the new motor. With using the same metals for both the head and cylinder the engines reliability increased to a point where a cross country ride was attainable for your average rider.
What better way to pay tribute to the then modern Harley-Davidson Twin than with a couple of young beauties. Devyn and Victoria gave me and the crew at Devils Head Choppers quite a show.
They enjoyed the motor as much as each other. These aren’t your average models. Devyn works part time at the shop turning wrenches and Victoria is as comfortable on a bike as she is taking her clothes off.
From 1984 to 1998 Harley-Davidson dropped the EVO motor in all of its big twin bikes. They continued to improve the motor in performance and size. The factory still rebuilds Evo engines and sells crate Evo engines, which are a terrific buy. As long as we keep putting gas in the tank, I can see Harley manufacturing this motor.
Since the Evo, we’ve faced the Twin Cam and now the M-8, which returned to the single cam, Evo configuration is many respects, but with the Twin cam oil pump.
The Evo remains the easiest to work on, long-lasting, inexpensive, traditional V-Twin of the Harley line-up. It saved the company in some respects and led Harley-Davidson is a new, very positive direction for many years. Long live the Evo, still my favorite.
–David “Dangerous Dave” Campbell
Earl’s Garage – Motorcycle, Hotrod, and Event Photography
