RACING CARS FROM THE SIXTIES
Alfa Romeo T33 (1968-9)
Italy
Alfa Romeo have one of the longest and most successful racing histories of any marque, probably second only to Mercedes. Their Type 158 gave Fangio many of his successes and was all successful in Formula 1 until the firm withdrew from racing. During the' 50S and early '60S Alfa concentrated on building up their production car side with the Giulietta and later Giulia models but in the early '60S they began to come back into racing via saloon car racing with the very rapid Giulia Sprint GT A which frequently won the I.6-litre class and often beat 2 litre or bigger cars until the Porsche 911 was homologated as a saloon. The success with the saloons encouraged the firm to venture further into racing and they took on Carlo Chiti, formerly of Ferrari and A TS to run the saloons under the separate Autodelta.name and to build up a team 4 of Group 6 sports racing cars to contest the 2-litre class which Porsche had sewn up in previous years. The cars were announced in January 1967 and immediately commenced battle for the World Prototype Championship. Unfortunately 1967 was a disaster for Alfa Romeo, because the cars suffered numerous failures in chassis and suspension while the engin~s were not powerful enough to keep up with the Porsches. In addition they lost drivers Jean Rolland and Leo Cella who were killed in unexplained accidents during testing. These crashes caused the team to miss several races in an endeavour to improve matters but each time they reappeared something new seemed to break. Their only placing of any note was fifth in the Nurburgring 1000 Kilometres but mostly they retired or failed to start.
During the winter of '67/68 a great deal of development work was undertaken and although the basic layout was retained many detailed improvements were undertaken. The chassis of the 33 is quite unique in that it is built from large diameter tubes, one down each side of the car and one across the rear of the cockpit joining the two side tubes. These tubes, about a foot in diameter, were made from aluminium in 1967 but a change to lighter, stronger titanium was made for 1968, with Pirelli rubber fuel bag tanks being inserted into the three tubes. At the front of the two side tubes a magnesium casting joins them and holds the front suspension, steering rack etc. This big casting was drilled for lightness in 1968 to help get the weight of the car down. The stronger 1968 front suspension uses single upper links with very wide based lower wishbones, springing being by coil spring/damper units. At the rear, the tubular sides arms are extended rearwards and inwards by short, smaller diameter tubes which support the engine and mount on a fabricated sheet steel rear bulkhead. Rear suspension utilises single transverse top links, reversed lower wishbones, and single radius arms each side together with outboard mounted coil spring/damper units. The radius arms are mounted at their forward ends on a steel roll over crash bar which passes over the car just ahead. of the engine. Girling ventilated disc brakes are fitted all round, outboard at the front and inboard next to the gearbox at the rear. Cast magnesium wheels of 13in diameter with 8.5 in rims at the front and 12 in rims at the back are used.
The V8 engine of the Type 33 has a passing resemblance to the I.5 litre ATS engine designed by Carlo Chiti but it was in fact designed by two Alfa engineers, Sata and Busso. The all aluminium unit has an angle of 90°, with cast iron liners, and twin overhead camshafts per bank driven by a double roller chain. Two valves per cylinder are used, although four valves per cylinder are being experimented with, but two plugs per cylinder are used. The Lucas fuel injection is fitted in the angle of the cylinder vee, the exhaust being mounted on the outsides of the heads. Bore is 78mm with a stroke of 52.2mm for a capacity of I,99Scc but a later 2.5-litre version has a stroke of 64.4 mm for 2,460cc. In 1968 form the engine gives 260bhp in 2-litre form at 9,000rpm on an 11:1 compression ratio and is mated to an Alfa-Romeo 6-speed gearbox of conventional two shaft design which is combined with its own integral limited slip differential. To give better drag coefficient the front mounted radiator was removed and replaced by two smaller ones just in front of the rear wheels. This enabled new coupe bodies to be designed with smoother nose sections, narrow cockpits and two large air intakes in front of the rear wheels for taking air to the radiators and brakes.
Things went much better in 1968 the team started out with 4th, 5th and 6th places in the Daytona 24 Hours, but although the cars were reliable they were still not fast enough and in England at the BOAC 500 they were slower than the Porsches and a privately entered Ferrari Dino, so work was intensified on the 2.5 and 3-litre versions of the engine. Nino Vaccarella had a 2.5 litre Type 33 at the Targa Florio which diced for the lead until co-driver Schutz hit a wall but the 2-litre cars ran reliably to finish 2nd, 3rd, 5th and 6th, with Nanni Galli and Ignazio Giunti driving the second placed car. This pair finished fifth in the Nurburgring 1000 Km. with the 2.5-litre car of Schutz and Bianchi finishing seventh after a broken alternator belt slowed it down. The team gave the Spa 1000 Km and Watkins Glen six hours a miss but sent a car for Teddy Pilette to drive in the Austrian GP which he placed fourth. At Le Mans the team entered cars in the 2-litre category and having found reliability the cars ran faultlessly if rather slowly, benefitting from the retirement of faster cars; at the end of the 24 hours they were in fourth, fifth and sixth places, led by the Galli/Giunti team once again.
This was a much better season, for the team gained I5.5 points in the manufacturers Championship and third place behind Ford and Porsche.
More Le Mans Cars from the 60ies onwards
Author: ArchitectPage
