
The Hammer of the Gods: Our Favorite Harley-Davidson Knucklehead Customs If Harley-Davidson has a "holy grail" engine, the EL Knucklehead is undoubtedly it. Produced between 1936 and 1947, the Knucklehead— named for the distinct shape of its rocker boxes—represented a massive technological leap for the Milwaukee firm. It was Harley’s first production overhead-valve (OHV)...

