The 1909 Renault Gray Model 5-D was the first Harley-Davidson motorcycle to feature a V-twin engine.

Curious about Top Fuel Harley horsepower? Discover how much power these beasts pack and how fast they can really go.

While core components, such as the milled aluminum and steel cradle frame, the enormous air-cooled 124 cubic inch S&S Cycle T124 V-twin engine, and the basic design, are shared—your Arch will be ...

When GMC launched the Twin Six V12 in 1961, it wanted to prove that gas engines could stand up to diesel mills in the heavy-duty segment — and, in some ways, it did with its magnificent low-end ...