In 1950 Alfa Romeo introduced a much more modern model; the '1900' had unitary construction in a body designed by Orazio Satta. Power came from an iron block dohc 1884cc engine, but from 1953 a 1975cc Super version was available and a 1975cc Ti version with twin carbs. The engine was upgraded to 1975cc for the '2000' in 1958 - sometimes called the 'cast iron 2-litre' to distinguish it from later alloy engines. The camshafts were revised for the 2000 but the 105-115bhp engine was a little weak for the heaver 2000 bodies. Sedans were designed and built by Alfa Romeo, Sprint Coupes by Giorgetto Giugiaro of Bertone, and Spiders by Carrozzeria Touring in Milan. The 2000 was replaced by the 2600 from 1961 which retained most of the bodywork of the 2000 cars but gave them a 2,584cc in-line 6-cylinder engine.