Some V engines with four camshafts have been marketed as "quad-cam" engines, however technically "quad-cam" would require four camshafts per cylinder bank (i.e. eight camshafts in total), therefore these engines are merely dual overhead camshaft engines.

Many DOHC engines have 4 valves per cylinder (sometimes 5, Audi or Volkswagen for instance). The camshaft usually operates the valves directly via a bucket tappet. A DOHC design permits