Alfa Romeo 33 Stradale

The 33 Stradale is one of the first production vehicles to feature forward-hinging butterfly doors.[9] The 33 Stradale also features side windows which seamlessly curve upward into the ' roof of the vehicle. The car features an aluminium body on an aluminium tubular chassis. As a result of being built by hand, each model differs from the others in some details. For example, the position of the windscreen wiper, and some of the later cars having vents added behind both the front and rear wheels to allow hot air from the brakes to escape is a differentiating factor.[10] The car has 13-inch Campagnolo magnesium-alloy wheels, the front wheels are eight and the rear wheels nine inches wide; the brakes used are disc brakes manufactured by Girling,[8] the rear ones are inboard. The suspension system of the car is directly derived from the Tipo 33 race car, with upper and lower control arms in the front and double trailing arms in the rear, along with substantial antiroll bars.[11]

The race-bred engine bore no resemblance to the mass-produced units in Alfa Romeo's more mainstream vehicles. The engine is closely related to the V8 of the Montreal, albeit with a smaller displacement and in a higher power output. The engines, despite being derived from the Tipo 33 racer cars, differed in many details. For example, the 33 Stradale's engines had chain driven camshafts as opposed to the racers' gear driven ones, but the Stradale kept the racing engine's flat plane crankshaft, whereas the Montreal engine had a crossplane crank. Race engineer Carlo Chiti had designed an oversquare bore x stroke of 78 mm × 52.2 mm (3.07 in × 2.06 in) while the all-aluminum 1,995 cc (2.0 L) V8 engine was dry-sump lubricated featuring SPICA fuel injection[12] with four ignition coils and twin spark plugs per cylinder. The engine used four chain-driven camshafts to operate the 2 valves per cylinder valvetrain featuring dual overhead camshafts and had a rev-limit of 10,000 rpm with a compression ratio of 10.5:1 [13] The engine has a maximum power output of 230 PS (227 hp; 169 kW) at 8,800 rpm and 206 N⋅m (152 lb⋅ft) at 7,000 rpm of torque in road trim and 270 PS (266 hp; 199 kW) in race trim.[3] Due to the hand-built nature of the drivetrain, the power output levels can vary by each car produced, for example the first production Stradale (No. 750.33.101) has a factory datasheet that states a power output of 243 PS (240 hp; 179 kW) at 9,400 rpm with a "street" exhaust and 254 PS (251 hp; 187 kW) with open exhaust.[14] The transmission is a 6-speed unit similar to the Tipo 33 race car, designed in house by Alfa Romeo.

Although the Stradale is a road legal car, it has some limitations which may make the everyday use slightly hard, for example missing locks and limited ground clearance.[8]

Prototype with twin headlights.
(Alfa Romeo Museum replica)

Production version with single headlights.

Prototype's side profile.
(Alfa Romeo museum replica).

Later production version with side vents both the front and rear wheels.

Rear three-quarter view of the prototype showcased in the Alfa Romeo Museum.

Interior of a 33 Stradale.

The car takes less than six seconds to attain 100 km/h (62 mph) from a standing start and has a claimed top speed of 260 km/h (160 mph). In 1968, the German Auto, Motor und Sport magazine measured a top speed of 252 km/h (156.6 mph) and 24.0 seconds for the standing kilometer which made it the fastest commercially available car for this distance at the time. It achieved this using an engine less than half the displacement of those in high-performance contemporary sports cars such as the Lamborghini Miura, Ferrari Daytona, and Maserati Ghibli.[3][4]

The Alfa Romeo Carabo displayed at the Museo Storico in 2015 with a depiction of the operation of its doors

The Carabo was designed by Marcello Gandini working under Bertone, who had already built his reputation by designing the Lamborghini Miura at the time. It is a wedge-shaped coupé with scissor doors. It was car was unveiled in 1968. The car was built on the chassis No. 750.33.109.[19]

Alfa Romeo Navajo

The Alfa Romeo Navajo concept car was unveiled at the 1976 Geneva Motor Show held in March of that year. The Navajo is based on the 33 Stradale[20] chassis No. 750.33.117.[21] It was given a full fibreglass coupé body with a desigb reminiscent of the angular and bold styling of the 1970s.[22] The car is equipped with 2-litre fuel injected (SPICA) V8 engine producing a power output of around 233 PS (171 kW; 230 hp) at 8,800 rpm.[18]

Between 1969 and 1971, Italian design house Pininfarina designed a total of three vehicles on two 33 Stradale chassis:

The Alfa Romeo P33 Roadster was presented to the public at the Turin Motor Show in November 1968. It was an open-top vehicle with a lower windscreen and a roll bar at rear painted in the colour of the body of the car.[23] The vehicle used in the chassis No. 750.33.108. Its whereabouts are unclear. Possibly the body of the P 33 was removed after the public exhibition, and the chassis re-bodied two years later to produce the Cuneo.

The 33/2 Coupé Speciale at the Alfa Romeo Museum

The Alfa Romeo 33/2 Coupé Speciale, also known as Alfa Romeo 33.2, is a Pininfarina designed concept car first presented to the public at the Paris Motor Show in 1969. This 2-door coupé was designed by Leonardo Fioravanti, then working at Pininfarina; the design was influenced by the Ferrari 250 P5 concept shown a year earlier at Geneva.[24] The 33.2 featured hydraulically operated butterfly doors and pop-up headlights.[25] It is based on the 33 Stradale chassis No. 750.33.115 and bears a striking yellow paint scheme.[26]

Alfa Romeo Cuneo

The Alfa Romeo Cuneo is an open-top, wedge-shaped concept car designed by Pininfarina that was presented at the Brussels Motor Show in January 1971. Popular belief is that it is probably also based on the chassis No. 750.33.108 which was used on the P 33 roadster.[27]

Alfa Romeo Iguana

The Iguana concept car, designed by Italdesign Giugiaro, was presented at the Turin Motor Show in November 1969. It is a two-seater sports coupé built on chassis No. 750.33.116. The design showed some new elements, that Giugiaro introduced later in production vehicle designs. The body of the Iguana was painted a metal-flake grey, while the roof frame and cabin pillars were finished in brushed metal, a treatment Giugiaro later applied to the DMC DeLorean. The front end of the Iguana inspired the designs for the Maserati Bora and Merak, and the rear of the car with its high-mounted tail lights formed the basis of the design of the Alfa Romeo Alfasud Sprint. Allegedly, a small series production of the Iguana was planned, but it never materialized.[28]