The Motor YEAR BOOK, 1951     Maserati.

 
The four-cylinder 1½-litre Maserati, with four valves per cylinder, made its racing debut in 1939. Since the war the chassis design has been substantially altered, the San Remo type having coil springs at the front and a stiff and lowered frame, whilst the engine has been modified to have two-stage supercharging with Roots blowers. This model was introduced in 1948 and, although unsuccessful in competition with the Alfa Romeo cars, it was (in their absence) the most successful racing car of 1949, winning six races and putting up the fastest lap on fourteen circuits. The comparative lack of reliability indicated by these figures was accentuated in 1950 by absence of work's support, with the consequence that the marque was only in the first three in one major race (Monaco) and secured only one victory. It should perhaps be mentioned that the Maserati brothers, who were responsible for the components upon which the San Remo type is based, have for the past two years been in business for themselves under the title O.S.C.A..
The Motor Year Book 1951