The history of Alfa Romeo sports prototypes in the late 1960s began with the Tipo 33, a car that achieved excellent results in the 1968 European Sportscar Championship in the sub-2000cc class, before stepping up to 2500cc with the V8.
In 1969 came the Alfa Romeo Tipo 33/3 with a new boxed chassis consisting of Avional panels designed to house the V8 engine, which was enlarged to 2998 cm3 but still in a rear-mid, longitudinally-mounted position, with the six-speed gearbox hung over the rear axle. The fibreglass body was adapted to the needs of each competition into a spider format or, on rarer occasions, a coupé.
The enlarged displacement hinted at the ambitions of Alfa Romeo, who were no longer content with class victories and were instead aiming for overall titles. The 90-degree V8 with dry crankcase lubrication was equipped with four valves per cylinder and four overhead camshafts with chain drive. It was fuelled by a Lucas indirect injection and developed 400 hp at 9000 rpm.
In 1971, the power was boosted to 420 hp at 9400 rpm, the gearbox modified from six to five speeds, the wheels reduced from 15″ to 13″ and the weight lowered to 650 kg following painstaking research.
Finally, the 33/3 outclassed much more powerful cars in numerous races, with De Adamich-Pescarolo taking the Brands Hatch 1000 km before Andrea De Adamich achieved another victory with Ronnie Peterson at the Watkins Glen 6 Hour race. The crowning achievement was a 1-2 finish in the Targa Florio, with Vaccarella-Hezemans winning ahead of De Adamich-Van Lennep.
Besides these spectacular results at continental level, there were also many victories in shorter hillclimb races that required power, agility and drivers who could get the best out of the car right from the start.