 Also notable is the smoother bodywork covering the engine, compared to the boxy design of the 20.The 22 is a single-seat race car primarily for the Formula Junior series and most had a Cosworth Mk.IV or Mk.XI engine with about .However, seven of the Lotus 22s were built with the then newly introduced Lotus TwinCam engine (designed for the Lotus Elan) for Formule Libre.