A new chassis was conceived by British designer Reid Railton (who had also successfully designed the Bluebird land speed record cars for Malcolm Campbell) and was constructed by Thomson & Taylor at Brooklands. The engine was based on the well-proven Riley six-cylinder unit, albeit this was modified in a number of significant ways. A stronger forged crankshaft with a large centre Hyatt roller bearing was made and an entirely new aluminium cylinder head designed. The engine was supercharged using a bespoke supercharger designed by Murray Jamieson who had worked with Mays and Berthon on the "White Riley". The ERA engine was designed around three capacities— a base 1488cc for the 1500cc racing class, one of 1088cc for the 1100cc class and also was capable of being expanded up to 1980cc for the 2000cc class. It ran on methanol and in its 1500cc form was capable of producing around 180–200 bhp and in excess of 250–275 bhp in 2000cc form.