Cosworth Mk series and MAE

The Cosworth Mk series and the MAE are the first engines the company sold, built in its early years on Ford Kent engine blocks with modified cylinder heads. Series production began with the Mk.II, Mk.V, Mk.VIII and Mk.XIV, which were sold to Lotus exclusively, and many of the racing engines up to the Mk.XII went to Team Lotus. The Formula Junior engines Mk.III, IV, XI and XVII started to bring in income from other customers, and the Mk.XIII, a pure racing engine based on the Lotus TwinCam that dominated the new Formula B of the Sports Car Club of America, secured the financial foundation of the company. The Mk.XVII and the MAE, which had intake port sleeves for a downdraft carburettor brazed into the cast iron head, could be considered Cosworth designs. The 997 cc MAE of 1965 was a dry sump engine of about 100 to 110 bhp for the new Formula 3 rules, it dominated the class until the one litre regulations ended in 1968, and it was mainly sold as a kit because Cosworth could not meet the demand.