• Knucklehead engines - Manufactured between 1936 and 1947. The knucklehead came in

     60 cubic inch (990 cc) and 74 cubic inch (1,200 cc) variations able to produce 40 and 45 horsepower respectively.

     

  • Panhead engines - Manufactured between 1948 and 1965. The panhead also came in 60 cubic inch (990 cc)

    and 74 cubic inch (1,200 cc) variations and produced 50 and 55 horsepower respectively.

    Big differences between the knucklehead and the panhead included aluminum heads on the panhead and internal oil lines,

    as opposed to external lines on the knucklehead.

     

  • Shovelhead engines - Manufactured between 1966 and 1985. Shovelheads displaced 74 cubic inches

    (1,200 cc) and produced 60 horsepower.

     

  • Evolution engines - Manufactured between 1984 and 1999. Displacement is 81.8 cubic inches
  •  (1,340 cc), and the engine produces 70 horsepower. Although the Evolution 1340cc is no longer in production,
  • the Sportster® model line of motorcycles receives Evolution engines with 883 cc and
  • 1200 cc displacements (manufactured 1986 to present).