 Higher HP models followed in the coming years.In 1914 Merosi designed the first Alfa Romeo DOHC engine, 4 cylinders, 4.5 litres and 16 valve head, this was used in the 1914 Alfa Romeo Grand Prix car driven by Giuseppe Campari.World War I temporarily stopped Alfa's activities and Merosi could start working again with DOHC engine only in 1922.