V-Rod Revolution Engine; Porsche and Harley make air and water mix.

Byline: GEORGE P. BLUMBERG

Motorcyclists often wave to one another in camaraderie. Many bikers greet all others, but some hard-core Harley-Davidson riders won't acknowledge another brand. Harley itself confused traditionalists when it introduced the V-Rod in 2002. Some Harley riders didn't know whether to wave or offer a single-digit salute when they saw it with its futuristic styling and a water-cooled, high-revving engine instead of the traditional loping air-cooled mill.

With an aging customer base, Harley needs new appeal. Younger riders want high performance, and not all are interested in tradition. In 1995, Harley decided to build a performance cruiser around a derivative of the liquid-cooled, 60-degree V-twin VR1000 racing engine campaigned on the Superbike circuit, originally developed with Cosworth and Roush. Horsepower brings heat, so liquid cooling would be used, for more power per specific displacement than air cooling and easier control of emissions and noise.

Harley partnered with Porsche Engineering Services to develop the street engine and the Kansas City engine line, loosely based on the VR1000 engine.

The V-Rod Revolution engine was introduced in 2002 as ...