6C 1500 (1925-1929)
In the mid-1920s, Alfa's RL was considered too large and heavy, so a new development began. The 2-liter formula that had led to Alfa Romeo winning the World Championship in 1925, changed to 1.5 liter for the 1926 season.
The 6C1500 was introduced in 1925 at Milan, production started 1927, with the P2 Grand Prix car as starting point. Engine capacity was now 1487 cc, against the P2's 1987 cc, while supercharging was dropped. First versions were bodied by Young and Touring.
In 1928, a 6C Sport was released, with a dual overhead camshafts engine. Its sport version won many races, including the 1928 Mille Miglia. Total production was 3000 (200 with DOHC engine).
Ten copies of a supercharged (compressore, compressor) Super Sport variant were also made.
6C 1750 (1929-1933)
The more powerful 6C 1750 (1752 cc actual) was introduced in 1929 in Rome. It was produced in six series between 1929-1933.
Base model had a single overhead cam; Super Sport and Gran Sport versions had double overhead cam engine (DOHC). Again, a supercharger was available.
Most of the cars were sold as rolling chassis and bodied by coachbuilders such as Zagato, Touring and James Young.
In 1929, it won every major racing event it was entered, including the Grands Prix of Belgium, Spain, Tunis and Monza, as well as the Mille Miglia was won with Giuseppe Campari and Giulio Ramponi, the Brooklands Double Twelve and the Ulster TT was won also, in 1930 it won again the Mille Miglia and Spa 24 Hours. Total production was 2635.
6C 1900 (1933)
The last derivate of original 1500 version, the 6C 1900 with a 1750 cc engine but with the bore increased by 3 mm to 68 mm, the 1917 cc engine was introduced in 1933, with an aluminium head for the first time on a 6 cylinder engine.
With 68 brake horsepower this version could achieve top speed of 130 kilometres per hour (81 mph).
The 1900 version is very rare as only 197 copies were made before it was replaced by 6C 2300.
Most of the Alfa 6C 1900's produced are made with a sedan body by Alfa Romeo, two-tone paint and four doors (hinged on the central pillar). Only the James Young, the British coachbuilder, Carrozzeria Touring and the Carrozzeria Castagna will make a few copies of the two door "spider" from the 6C 1900.
6C 2300 (1934-1937)
The 6C 2300 (2309 cc) was designed by Vittorio Jano as a cheaper alternative to the 8C. In 1934 Alfa Romeo had become a state-owned enterprise.
This year was presented a new 6C model with a newly designed, larger engine. Chassis technology, however, had been taken from the predecessor.
One year later, a revised model, called the 6C 2300 B was presented. In this version the engine was placed in a completely newly designed chassis, with individual front suspension and rear swing axle, and hydraulic brakes.
The 6C-2300 was produced in 760 copies with rigid axles and 870 copies of the B-model.
6C 2300 Aerodinamica Spider (1935)
In 1935, Vittorio Jano, working with the brothers Gino and Oscar Jankovitz, created a one-off mid-engine prototype on a 6C 2300 chassis (no. 700316), which Jano had shipped to Fiume, Croatia in 1934. The brothers Jankovitz had been close friends with leading Hungarian aerodynamicist Paul Jaray, and the prototype, called the Alfa Romeo Aerodinamica Spider, was an especially early and clear example of ponton styling — a genre that would overtake automobile styling and last until the 1960s. Jano had intended to fit a V12 engine, though that possibility disappeared when Jano himself was fired from Alfa in 1937.
Based on documents kept in the family Jankovits the history of the car's development is as follows: summary of the "Aerospider" Alfa Romeo Jankovits - 6 C 2300 Aerodinamica Spider "Aerospider" (constructed 1934-1937)
The prototype of modern automobile design and the first car which had been constructed and executed as a sculptural whole.
The combination of a very advanced aerodynamic body with the engine behind the central driver's seat, on the most advanced chassis of its time makes this Alfa Romeo unique in the history of automobiles.
This special version of an Alfa Romeo 6C 2300 belonged to a secret project by Vittorio Jano and the brothers Jankovits.
The Aerospider represents
- The first supercar of “modern” sports car design.
- The first mid-engined car with central driving position in the history of automobiles designed to keep the centre of gravity in the middle of the car - 60 years ahead of the McLaren F1
- The first car designed to take account of newly developed principles of aerodynamics, to provide low-drag both externally and internally.
- flowing lines with a low body profile, a steep short radiator grille and a long descending tail; side wings with a convex surface at each side of the car, and concave surfaces towards the midline, resulting in a cross-section resembling a bat
- a straight upper line to the silhouette of the side of the car, without interruptions or steps
- a streamlined bodyshell which minimised disturbance to the air flow. For the first time in car design door handles and lights were integrated into the body of the car
- a body design with air inlets in zones of high air pressure, and with the outlets of heated air from the engine and brakes in areas of low pressure.
The first car which was designed for high speeds by using:
- a body which fully enveloped the underside of the car to reduce air turbulence beneath it
- an aerodynamic front design to reduce front lift of the car
This aerodynamic design was scientifically aerodynamic and lasciviously beautiful without heritage, a forerunner of the later following high-speed record-breaking cars of Mercedes and Auto Union, and in some respects even more advanced than they were, and a forerunner of modern sports car, pure, simple and structural.
The car had the most advanced chassis of any pre-war car. It was the first car in history to use:
- a two-circuit brake system with adjustable duplex brakes, with an equaliser which could avoid overbraking by changing the distribution of braking force between the front and rear brakes during driving.
- a hydraulically-assisted clutch
- a horizontal radiator which made it possible to design the lowest front profile of any pre-war car
- “silent bloc” bushes
- disc style flexible couplings, later called “Hardy discs”
- exhaust pipes of equal length for better performance
- improved intake of air to reduce the pressure drop
- a unique system of gear change with pre-selection
- features which were designed to avoid the specific problems of a mid-engined racing car, such as overheating and abrupt spinning, which had still not been fully resolved 30 years later.
- length: 4,750 mm (187.0 in)
- width: 1,720 mm (67.7 in)
- height: 1,030 mm (40.6 in) (1,150 mm (45.3 in) with windscreen)
- wheelbase: 2,800 mm (110.2 in)
- track: 1,560 mm (61.4 in) (front), 1,505 mm (59.3 in) (rear)
- weight: 950 kg (2,100 lb) (dry)
Engine: Prototype of Alfa Romeo high performance 6 C 2300 built in 1934, No. 700316, placed behind the driver, iron-block, light alloy head, dual-overhead-cam 2309 cc, straight-six, camshafts chain-driven, spur gears, wet sump lubrication, three dual Weber 36 D 04 carburettors, improved intake of combustion air, adjustable timing of ignition.
This was the engine to be used for the sports version of the project. The engine for the race version would have been the 12 C of 430 hp.
- Max Power 105 bhp (78 kW) at 4800 rpm; torque 170 N·m (130 lbf·ft)
- and speed: over 140 mph (230 km/h) for sports version
over 200 mph (320 km/h) for race version (estimated).
- Transmission: Alfa Romeo 4-speed plus reverse, mounted with Hardy disc behind the engine, driven rear wheels, draulically-assisted clutch, pre-selective gearbox
- Chassis: frame prototype suitable for 12 C engine, No. 700316, reinforced and modified for centre position of the engine
- Suspension: All-independent, upgraded Auto Union race suspension with “silent bloc” bushes;
front: top wishbones with lever-arm “Houdaille” hydraulic shock absorbers, transverse leaf spring and longitudinal torsion bars; rear: swing axles, radius arms, transverse leaf spring,longitudinal torsion bars
- Steering: Worm and sector with Hardy disc
- Brakes: two-circuit hydraulic brake system with two fluid distributors and two master brake cylinders, one for the front and one for the rear, duplex race brakes type “Lockheed”, 17-by-2-inch (430 × 51 mm) drums all round, adjustable rear brakes, equaliser of brake force for adjustment during driving to avoid overbraking
- Wheels: Alfa Romeo 18 inches (460 mm) “Rudge” wire spoke
- Tyres: 5.50-18 racing crossplies
- Body: Steel three-seater with central driving position, streamlined with fully enveloping underbody and integrated wings; body work designed by Oscar Jankovits, built at the Jankovits garage in Fiume, 1936–1937
- Production: One prototype
In 1934, the chief engineer of Alfa Romeo, Vittorio Jano, had been impressed by the new mid-engined Auto Union GP racer. Jano was aware of the advantages of a mid-engined car and wanted to make use of the same technology. He was planning to develop a dual-purpose car. as racer to be fitted with a 12 C engine and as sports car with an 6 C engine. But Alfa Romeo had never constructed a mid-engined car, and had no experience of the characteristics of such a design. He decided to develop in-house a V12 engine for Alfa Romeo’s standard GP chassis, which could later also be installed into the yet-to-be-developed mid-engined chassis which he wanted to construct. This was to be a top secret project. Chassis and body were designed and built outside the Alfa Romeo factory to hide it from competitors.
Jano, who was of Hungarian descent, was in contact with two other men also of Hungarian descent, who were interested in the project. They were the brothers Gino and Oscar Jankovits. They were brilliant students at the Polytechnic University in Jano’s home town of Turin, where Fiat and Alfa Romeo recruited their technical staff. The brothers became Alfa Romeo concessionaires and owned the biggest garage of Istria in Fiume – today called Rijeka. With their passion for race cars and the background of wealth, technical talent and the garage they were excited at being able to participate in this project, and they financed the entire project.
In 1934, Jano gave them a powerful, naturally aspirated 6C 2300 engine upgraded with three Weber carburettors. This would be the engine for the sports car project. Jankovits also got the transmission system, and a basic frame suitable for the 12 C engine, to be modified for a mid-engined racing car. Other mechanical systems such as suspensions and brakes were designed by the development team and built at Portello.
Each mechanical part produced for the new car was marked with a description and date of production, and with the position where it was to be mounted. The parts were then taken to Fiume, and between 1935 and 1936 were installed and tested by the Jankovits in a “running chassis”. Depending on test results, improvements were made, regardless of cost, until the systems worked to their satisfaction. All parts of the chassis were constructed very solid with view to high speed trials over 250 mph (400 km/h). The Aerospider’s chassis was the most advanced of its time and anticipated later designs by Mercedes and Auto Union. It was the first car with a suspension designed with wishbones, hydraulic dampers, transverse leaf springs, radius arms and torsion bars. Other pioneering features were devices to eliminate overbraking and a sophisticated system of gear change with pre-selection.
The breathtaking aerodynamic shape of the car also anticipated the later high speed designs of Auto Union by 4 years. It was designed by Oscar Jankovits, who was probably in contact with Josef Mickl, Porsche's specialist of aerodynamics, and others of the former Habsburg Empire as Paul Jaray, the inventor of streamlined cars, and Bela Barenyi, the inventor of the “Volkswagen”. The exceptional streamlined steel body was built by workers at the Jankovits Garage in Fiume between 1936 and 1937.
The Aerospider was to have been fitted with the newly developed V12 engine (430 hp) of Alfa Romeo - a "12 C Aerodinamica Spider" - which would have made it a serious competitor to Auto Union and Mercedes Benz. But in 1937, when the car was ready to make its public appearance, the project was abruptly stopped when Vittorio Jano was dismissed by Alfa Romeo. Jankovits could no longer get the 12 C engine. They mounted the 6 C 2300 which they had got for the sports car project, and they made the prototype suitable for use on the road by adding user-friendly components such as a bigger windscreen, a heating system and bumpers. The car still has its original licence plate and documents of registration.
Any public appearance of the futuristic looking Aerospider would have caused a sensation, but because of the secrecy surrounding the project, and then the onset of the war, the prototype remained hidden in the Jankovits’ garage in Fiume, and was not seen by anyone from outside the garage. On Christmas Eve 1946, Gino Jankovits drove the Aerospider at full speed under the toll-bar of the closed communist controlled border into Italy. Border guards fired volleys of shots after him, but the low, streamlined body saved Gino’s life. Only the rear tyres were destroyed by the bullets, which also caused some dents in the rear of the car’s bodywork. To get money they had to sell their car to an Anglo-American officer. Then the Alfa disappeared for about 20 years until it was rediscovered in England. In 1978 the Aerospider was recognized by the well-known Alfa Romeo historian Luigi Fusi, who had worked with Vittorio Jano at the time of the Aerospider project. He wanted to acquire the car for the Alfa Romeo Museum. The acquisition failed, but the prototype did eventually return to Italy, 30 years after its birth, to be restored at last to its original condition as a racing car.
Time frame of construction of the Aerospider
- 1934 construction of engine, transmission and frame
- 1935 completion of first version of chassis
- 1936 testing period, modifications of chassis, start of body making
- 1937 completion of chassis and body for race car
- 1938 modification into street car
6C 2500 (1938-1952)
Introduced in 1938, the 2500 (2443 cc) was the last 6C road car. World War II was coming and car development was stopped, but a few hundred 6C 2500s were built from 1940-1945.
Postwar, the first new Alfa model was the 1946 6C 2500 Freccia d'Oro (Golden Arrow), of which 680 were built through 1951, with bodies by Alfa.
The 2500 had enlarged engine compared to the predecessor model, this Vittorio Jano designed double overhead cam engine was available either one or three Weber carburetos. The triple carburetor version was used in the top of line SS (Super Sport) version.
The 2443 cc engine was mounted to steel steel ladder frame chassis, which was offered with three wheelbase lengths: 3,250 mm (128.0 in) on the Turismo, 3,000 mm (118.1 in) on the Sport and 2,700 mm (106.3 in) on the Super Sport. Various coachbuilders made their own versions of the 2500, but most of the bodyworks was made by Touring of Milan.
The Tipo 256 was a racing version of 2500 made eight copies between 1939-1940 for Mille Miglia and the 24 Hours of Le Mans. It was made as Spider (convertible) and Berlinetta (coupe) Touring bodystyles. With power of 125 bhp (93 kW) it could achieve top speed of 200 kilometres per hour (120 mph).
It was sold to wealthy customers like King Farouk, Alì Khan, Rita Hayworth, Tyrone Power, and Prince Rainier. The 2500 was one the most expensive cars available at its own time. The last 6C was produced in 1952, and was replaced by the 1900.
6C 2500 Freccia d'Oro
The 6C 2500 Freccia d'Oro (Golden Arrow) was the first postwar Alfa Romeo it was built 680 through 1951, with bodies by Alfa. The car was Berlina bodystyle with 5-6 seats based on 2500 Sport. It has wheelbase of 3,000 millimetres (120 in) and it weights 1,550 kilograms (3,400 lb). With 4-speed manual gearbox this 90 bhp (67 kW) car could achieve top speed of 155 kilometres per hour (96 mph).
6C 2500 Villa d'Este
The 6C 2500 Villa d'Este was introduced in 1949 and was produced until 1952, named for the Concorso d'Eleganza held in Villa d'Este; a Touring Superleggera-bodied version won the prize. Villa d'Este was Alfa's last hand built model, only 36 examples made.
6C 2500 Coloniale
The 2500 Coloniale was a special version of 6C, used by the highest military authorities and government. The car was designed by the request of the Italian Ministry of Defense in 1938 for use in the numerous Italian colonies. At that time, the Italian had many colonies in Africa. Two prototypes of the model Alfa 6C 2500 Coloniale were manufactured by Alfa Romeo in 1939. Giambattista Guidotti had been instructed to test two prototypes in East Africa. He had already led an Alfa Romeo 8C 2300B Mille Miglia in 1937. The car will be the first to be manufactured using technology developed by the renowned Carrozzeria Touring, the Superleggera. Actual production began in 1941. The car had two spare wheels, a fuel tank of 120 liters and four additional reserves with a capacity of 70 liters of gasoline. In addition, the differential can be locked from the dashboard by the driver. Production of Coloniale stopped in 1942 due to the war, when 150 vehicles, plus two prototypes were produced.
6C 3000 (1950-1954)
A 6C 3000 was prototype made in 1950, basically a 2500 with a 3L engine. It did not appear until 1952, as the Competizione Maggiorata (CM), built for racing, with a 3.5L engine, in four coupé and two spider versions.
- 6C 3000 (1948)
- 6C 3000 50 (1950)
- 6C 3000 CM (1952) 275 bhp (205 kW), 250 km/h (160 mph) ("Competizione Maggiorata" for enlarged displacement)
- 6C 3000 PR (1954) ("Passo Ridotto" for shortened wheelbase)
6C 3000 Competizione Maggiorata
6C 3000 Competizione Maggiorata was born in 1952. The body was shaped by Carrozzeria Colli, a coachbuilder from Milan, with some remembrances from the style introduced by 1900 Disco Volante. The propulsion system of this model comes from a project by Giuseppe Busso. It was different from his ancestor: it still used several components of the 3-liters-volume/6-cylinders system from the 6C 3000 prototype, but engine capacity was increased to 3495 cc. After several evolutions, it reached a power of 275 bhp (205 kW).
3000 CM was realised in six copies: four coupé and two spider. With the coupé model Juan Manuel Fangio and Giulio Sala got the second position at Mille Miglia, in 1953. Fangio was leading the race, but a problem whit the chassis obliged him to slow down. Still with Fangio, the spider won the First Gran Premio Supercorte Maggiore in Meran, 1953; this car is shown today at Museo Storico Alfa Romeo.
One of the two spider was modified to cope with the new rules of the International Sport Category and the capacity was limited to 3-liters. This car was renamed PR, Passo Ridotto (Reduced Wheelbase). This second spider belongs to the Museo Storico Alfa Romeo’s collection.
During the sixties, at the end of the period of competitions, 6C 3000 CM was used by the Experience Department of Alfa Romeo for testing new components, one of which is the disc brake, which is still present today in this vehicle.