In many ways, it was the quest for reduction of mechanical noise that drove the Revolution into being an all-new engine, one that shares architecture but not components with the VR. Noise laws worldwide, and especially in Europe, have been getting tighter. If Harley intended to build an engine for the new century, it would have to be one that could meet all of that century's current and proposed standards. Another motivation for change was time: "We were pretty busy with the Twin Cam engine when this project started," says Coughlin. The solution Harley found for its shortage of engineering personnel was to enlist the aid of an old ally in the design of the Revolution: Porsche Engineering. The consulting division of Porsche had worked closely with Harley before, including designing the never-produced V-Four Nova in the last days of AMF ownership. Now Harley turned to Porsche again, enlisting the Germans, aided by a small team of Milwaukee engineers, to help transform the VR concept into a new engine. The emphasis would be on strength, produceability and quiet, rather than on the performance-at-any-cost goals of the VR.