Ten years after selling the company bearing their name to Adolfo Orsi in 1937, and remaining for those ten years as employees of the company, the Maserati brothers founded Officine Specializzate Costruzioni Automobili – Fratelli Maserati SpA better known as O.S.C.A in 1947.

Towards the beginning of the 1951 Grand Prix season Prince Bira had one of his three year old Maserati 4CLT/48’s fitted with a new 4.5 litre OSCA 60º V12 motor that produced 330hp to replace the regular 1.5 litre 4 cylinder supercharged motor.

The Prince recorded a debut win with the new motor in the Richmond Trophy at Goodwood and raced with it on at least four further occasions scoring a best 4th in the 1951 Bordeaux Grand Prix concluding his season with a retirement from the 1951 World Drivers Championship Spanish Grand Prix after completing just 1 lap with engine failure.

A little over a month before the Spanish Grand Prix O.S.C.A turned out with their own Formula One challenger, today’s featured 4500G powered by the same type of alloy block V12 as they had supplied to Bira.

Franco Rol qualified 18th of the 21 starters for the 1951 Italian Grand Prix and completed all but 13 laps of the full distance to be the last classified finisher, in a career high, 9th place.

In the absence of sufficient commitment from manufacturers to continue with the 1.5 litre / 91.5 cui / supercharged / 4.5 / 274.5 cui litre normally aspirated Formula One powered cars, the 1952 and ’53 World Drivers Championships were decided by running the series for 2 litre / 122 cui Formula Two cars.

Consequently the last all new type to appear in the 1951 Formula One championship season and the only car built specifically to compete in Formula One races by the Maserati brothers remains the OSCA 4500G seen in these photographs at last years Silverstone Classic being driven by Stephan Rettenmaier.

Thanks for joining me on this “Last New 4.5 Litre” edition of “Gettin’ a li’l psycho on tyres” I hope you will join me again tomorrow. Don’t forget to come back now !