It is now clear that the styling research for this car was strongly conditioned by the functional (the integral openings of the front and rear bonnets, for example) and aerodynamic requirements of the vehicle. And yet everything about this bodywork is perfectly harmonised, without hesitation or style lapses. As is appropriately emphasised in a brief graphic presentation of the ’33 Stradale’ issued by the Marazzi coachworks in Caronno Pertusella – which built the car in 1 mm thick Peraluman H35 just a stone’s throw from the Museo Storico Alfa Romeo in Arese – the ’33 Stradale’ is an example of high style ‘somewhere between the work of the craftsman and the work of the artist’. It was the first road car to have ‘butterfly’ opening doors that also hinged on the roof with the windows wrapping around the roof, designed to amaze but also to be practical because they improved accessibility to a very low and relatively narrow passenger compartment, and the grilles on the front and rear wheel arches, open to prevent dangerous overpressure caused by the movement of the wheels. A model, that of the 33 Stradale, which is still used today as an example to describe the perfect balance between refined mechanics and the style that surrounds it, in a balance that can be summed up in a phrase dear to the brand: ‘Essential beauty’.
An extremely sophisticated car, the chassis complete with engine and gearbox was built directly by Autodelta, alongside the Tipo 33 racing cars. The engine, the same as in the Tipo 33 competition car, is a 1995 cc 8-cylinder 90° V8 with a bore of 78 mm and stroke of 52.2 mm, designed by Alfa Romeo Mechanical Design Director Giuseppe Busso and then developed by Autodelta.
An authentic technological jewel, built entirely in aluminium and magnesium, it had a double overhead camshaft timing system for each bank, two 48° tilted valves per cylinder (33 mm diameter intake valve and 28 mm diameter exhaust valve), sixteen spark plugs (two per cylinder), Spica indirect mechanical injection system with double electric fuel pump and dry sump lubrication. In the competition version the engine delivered 270 hp at 9600 rpm with a compression ratio of 11:1, while power in the road version was limited to 230 hp at 8800 rpm thanks to the lower compression ratio of 10:1 to make the engine more suitable for road use. Nevertheless, this remains one of the most powerful naturally aspirated 2000 cc engines ever made with a record top speed for the time, which even today remains very fast for a road car. Its 230 hp is a lot of power for a road car, when achieved with mechanical technology alone and without the help of electronic management adopted by modern cars. This engine was mated to a 6-speed manual transmission coupled to a self-locking differential mounted cantilevered over the rear axle. The 33 Stradale was very light (690 kg) and compact and was capable of very high performance for the time, as it is today, with a 2-litre naturally aspirated engine. In fact, the declared top speed was 260 km/h and acceleration from 0 to 100 km/h was 5.6 seconds. Auto Italiana magazine, which tested the car in February 1969, recorded 4.9 seconds from 0 to 100 kph and a top speed of 245 kph.