The V-Rod engine is manufactured inhouse by H-D at their Milwaukee plant. Porsche is credited with assisting in the re-design of Harley's VR1000 race engine that Harley campaigned in sanctioned A.M.A Superbike races with somewhat lackluster results a few years ago during the late 1990s, that was to become the V-Rod or "Revolution" motor we know today.
(this, according to a Cycle World article I remember reading back in 2002 when the V-Rod first hit the market)
I have to admit that I think it one of the better looking liquid-cooled motorcycle engines out there.
As Dennis has mentioned here, most reviews of the entire machine tend to rave about the bike's motor, but say the machine's frame geometry leaves a bit to be desired, as these reviewer find it tends to fall into turns and not give riders much of a sense of stability during those turns.
