The 500cc Formula 3 specification was superseded in 1958 by Formula Junior, with engine capacities of 1000cc (360 kg chassis) or 1100cc (400 kg chassis) that were derived from production cars, rather than motorcycles [REF].
In 1964, the Fédération Internationale de l'Automobile (FIA) ended Formula Junior and returned to Formula Three, but this time with 1000cc four-cylinder production-based engines [REF].