Ing. Marelli took the tubular frame of the 33TT and equipped the 8-cylinder engine with four valve cylinder heads and mechanical fuel injection from Lucas. It was coupled to a 5-speed non-synchro gearbox. He chose the tubular frame because it was easier to adapt and quickly construct the new body with the front windscreen made of laminated glass. Compared to the previous box-aluminum chassis, it also allowed better visibility and more room for the pilot and navigator.
Autodelta never had a chance to wind tunnel the design and it was built according to the drawings supplied by Marelli, which in turn were based on experiences gained with the previous T33 prototypes.
Says Ing. Marelli, ”The car was tested and carried out on the track only by Jean-Claude Andruet. Personally I personally followed the development of the car on the track and on the road, as well as its participation in the Tour of Italy. Due to the lap times, from the beginning I knew that the car was a potential winner and that only the Stratos of Munari would be our only real opponent.
“At the end of the tests, the car was completely disassembled in every detail, including engine. This test was positive and it was decided to prepare the car to participate in the Tour of Italy. When the car was prepared and undergoing final tests, I noticed that on the left bank there was a small oil leakage. I asked the mechanics to intervene quickly, and we considered the possibility of replacing the engine block or the entire engine. I was told not to be so pessimistic, and that a small leakage would not affect the outcome of the race.”
As we shall see, this was not the case.
Stradale’s first and only competitive event
To compete in the 1975 Giro d’Italia Automobilistico, the 33TT3 Stradale received the chassis number 78033.114, and the registration plate number Prova MI-1310. The event began in Turin, October 12, 1975 and ended up back in Turin on Friday, October 17. Much like the Tour d’ France, the Italian event was a rally between various venues in Italy, beginning with Monza, moving on to Imola, Santa Monica, Vallelunga and assorted hillclimbs along the way.
As scheduled, the event took off in the historic center of Turin, but not everything went smoothly; the public was virtually absent due to a strong driving rain and snow on the track. At Monza, the V8 engined T33 driven by Anduret and Carlotto was already having engine problems keeping it running on all eight cylinders, and finished third in the provisional results of the first leg. The main competition came from the Stratos of Facetti-Garzoglio which finished first.
The second stage, which consisted of speed tests on Dino Ferrari circuit in Imola and Santa Monica in Misano Adriatico, saw the T33 still running rough but nevertheless was ahead on overall points by the end of the leg.
The third stage was dominated by the Alfa, which won the first of two speed tests and consolidated its top position in the overall standings. Things were looking better for the Autodelta entry, despite very stiff opposition from the Turin-based Fiat 031 and the two very fast Lancia Stratos of Munari and Facetti. But the oil leakage notice by Marelli in tests was now a serious problem, creating clouds of smoke as the oil leaked onto the hot exhaust system.
And that came to head when on the fourth stage, during the speed test at Vallelunga, the ’33TT Stradale was again plagued by engine problems and was forced to retire.
Engineer Marelli reported that “The ‘small crack’ that I highlighted on the cylinder block of the engine after the first test was enlarged and the problems became apparent in the second stage. Then, the crack turned into a real hole in the lubrication circuit thus causing a loss such as to reduce the lubricating oil pressure to zero and cause the subsequent breaking of the main bearing.”
There was nothing left to do. The Alfa returned to Milan with no win while the 3rd edition of the Tour of Italy was won by the Fiat Abarth 031.
After the event, Andruet told a colleague from the BBC: “ I’m sorry for the Alfa and for the engineer. Marelli, who dedicated himself with great commitment to the preparation of this machine. We have shown the car is able to travel well on the road, on uneven ground, and perhaps even off-road. It should go very well in rallies France with less asphalt. I hope that Alfa insists on this program. The ’33’ of the Tour may very well be the forerunner of an ideal car for rallies.”
However, the stunning Alfa Romeo ’33TT-Stradale’ was finally abandoned for political reasons and, as concluded Ing. Marelli concluded: “Our ’33TT-Stradale’ Autodelta did not participate in any competition.“ It would lay idle at Autodelta until rediscovered by Joe Nastasi."
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