Return of the long lost V12-powered 1941 Alfa-Romeo 12C Prototipo

Return of the long lost V12-powered 1941 Alfa-Romeo 12C Prototipo

From the ashes of war arose a unique Alfa Romeo V12 engine. Its survival in an equally mysterious body is a saga unknown until now, as Karl Ludvigsen reveals Photography Spalluto Press.


ALFA’S SECRET V12

Return of the long lost V12-powered Alfa

The incredible story of the rediscovery and restoration of one of the marque’s most important missing links


The recent revelation of a beguiling Alfa Romeo sports roadster with a radical V12 engine and an enigmatic history has caused quite a commotion in the classic car realm. Officially revealed at Alfa Romeo’s F1 headquarters as part of its celebration of 111 years in the business, the12C Prototipo – as it’s been dubbed – has prompted all the frenzied attention and speculation that its dramatic appearance warrants. Not least whether this Alfa V12 might have been the kernel of what became Gioachino Colombo’s legendary Ferrari V12. It’s time for the story of its creation and history to be made known. In 1938 Alfa Romeo’s major-domo Ugo Gobbato commissioned his R&D chief Wifredo Ricart to build sports-racing and Grand Prix designs. Sadly, the Spanish engineer’s creations would turn out to be too elaborate ever to reach the starting line. This was all too obvious to Enzo Ferrari, who was still involved in the Alfa Corse team operations at that time. Gobbato also needed someone to attend to his Milan company’s production cars. This had been all but ignored in the 1930s in favour of aero engines and racing cars. Veteran engineer Vittorio Jano had decamped to Lancia, so a crucial position was open. For this task he chose Bruno Trevisan, a reserve major in Italy’s Air Force. In the words of Enzo Ferrari: ‘Trevisan was the son of Gobbato’s professor when he was studying in Vicenza at the institute for industrial experts, before graduating in engineering.’


Return of the long lost V12-powered 1941 Alfa-Romeo 12C Prototipo

Above and facing page It’s not only the V12 engine that makes this car special: it’s believed four of those were built, but the 12C Prototipo’s body is unique, and its re-emergence only recent.


Having served as an engine expert at Fiat, Trevisan moved to Alfa Romeo in October 1934. His first task was to design a new V12 racing engine to install in the new chassis left by Jano. He did a commendable job with a supercharged 12 that ultimately reached 4. litres and 430 horsepower, winning races for Alfa. Next he turned to the freshening of Alfa’s staple six-cylinder 6C 2300 B. He gave it a synchronised transmission and in 1939 further updated the model as the 6C 2500. In 1938 Bruno Trevisan’s team was engaged in designing the cars that would represent the future of Alfa. In their files were the departed Jano’s gift of the Tipo 1, a new 1.-litre four planned in two versions: one a single overhead camshaft and the other a twin-cam, both with inclined valves and aluminium cylinder heads. These, however, remained prototypes when Gobbato decided that an ambitious Italy needed luxury models from Alfa, while Fiat would supply the needs of the lesser folk. Two categories were covered. One, the Tipo S10, was the 3 ½ -litre premium entry with a 12-cylinder engine and 128-inch wheelbase. The other, the Tipo S11, suited the more-mainstream 2.-litre category with a V8 engine on a 112-inch wheelbase. Both would have fashionable integral body/frame construction and all-independent suspension. Sports versions would also be produced.

At the very same time, an important rival was making plans for a new engine range. Under the direction of Hans-Gustav Röhr, the Mercedes team was actively at work on two new engines, a V8 and V12, which shared a number of components. Their capacities respectively were 4.0 and 6.0 litres, sized to suit successors to such cars as the Type 540K of 5.4 litres. They failed to get them installed in cars, but more than 3000 of the larger V12 were produced to power searchlights.

Bruno Trevisan sweated the details of Alfa’s all-new engines based on 1935 studies left by Jano, using his valve-gear with tappets screwed onto the valve stems. Although differing in their vee angles, 90º for the V8 and 60º for the V12, they shared a 68mm cylinder bore. This permitted identical wet sleeves and pistons for both. Valve inclination from the vertical, opened by chain-driven single overhead camshafts, was 30º from the cylinder centreline. Along their inboard inlet faces, the cylinder heads leaned towards the engine’s centre at 15º.Hence the same set of machine tools could be used to carry out the main operations on the cylinder heads of both. For the V8, Trevisan also designed twin-cam heads, using a Jano-influenced wide vee-angle for its valves.

Illustrations show sober standard coachwork for each model in accord with mainstream Alfa tradition. Mocked up for a sports version of the V12 version – the S10 SS – was a coupé with leaf-sprung live rear axle. The tuned engine exploited a higher compression ratio for racing fuel and triple carburettors to deliver 165bhp at 4700rpm, up from the standard 140 at the same speed. Alfa hoped to have three such sports-racers for the 1941 Mille Miglia but none was completed and the race was never run.

In May 1941 came ‘an event of considerable importance in Alfa’, as engineer Giuseppe Busso wrote. ‘Something from Jano’s period had survived: the prototypes of two large cars. They were at an advanced stage of design and construction. One was the S10 with a 12-cylinder vee engine. Instead of the original design with 68 x 82mm dimensions displacing 3560cc, it had the smaller bore of 62 mm for 2971cc to bring it into the 3.0-litre class. No power ratings for this smaller engine are available. The other was the S11 V8, with eight cylinders, of 2260cc.’ Busso continued: ‘At a certain point Ugo Gobbato, the sworn enemy not only of indefinite situations but also of long periods without results, must have deemed a radical intervention necessary for a clearer, better defined approach. It was 31 May 1941 when he sent his personal communication to the various internal bodies. It was certainly historic not only for its instructions but also, in my opinion, for the almost brutal attitude with which Gobbato expressed himself.’

The end of the road for the Bruno Trevisan creations was indeed emphatically defined by the terse missive from Gobbato requiring that ‘arrangements that all work relating to these cars be suspended’. The V8 had progressed well, with two prototype automobiles completed and ‘tested with good success’, according to engineer and historian Luigi Fusi. Trevisan’s V12s had also been brought to life. Post-war reconstruction suggests that four engines were built, two of the ‘touring’ S10 and two of the ‘racy’ S10 SS. The ‘touring’ twelves were installed in two prototype saloons, at least one of them by late 1943, when it was requisitioned for a German Colonel. Alfa engineer Gian Paolo Garcea recalled that, when he returned to the works in peacetime, he and Luigi Bazzi were proudly driven in ‘the most imposing vehicle in the division: the S10 saloon with a 12-cylinder engine. A prototype still in perfect condition, and all polished up.’ This was likely the example Gobbato used personally.

During wartime, Alfa’s engineers had upped stakes from Milan on 10 December 1942,moving to Ameno on the shore of Lake Orta, north-west of Milan and its aerial attacks. Ricart started work on a hyper-elaborate 28-cylinder aero engine and an all-new passenger car, the Gazzella. This had a 2.0-litre twin-cam six under its bonnet and a rear transaxle. The Spaniard would pursue these projects until the expiration of his Alfa contract on 31 March 1945, but the condition of the Milan works after the bombing was not conducive to the launch of an all-new car.

A bolt hole for Alfa’s mechanical assets for the duration was east of Milan at Melzo, where the company had a spacious branch operation. Some of the treasured Tipo 158 racing cars were there, as were 8C 2900 cars and chassis. A model that first appeared in 1935, the 8C 2900 was the great sports car of its era, sustained until the war. Available in two wheelbases – ‘sports’ and ‘touring’ – the car was powered by a 2.9-litre straight-eight that had twin camshafts and dual Roots blowers. An engine-mounted clutch drove via a rear-mounted transaxle that suited its Porsche-designed all-independent suspension.

Disposing of some 180bhp at 5200rpm from its 2.9 litres, the 8C 2900 ruled the sports-car-racing roost. It won the Mille Miglia from 1936 through 1939 and then the first post-war race in 1947. In 1948 Heinz- Ulrich ‘Uli’ Wieselmann drove an 8C 2900B.

‘What is masterful, enthralling and electrifying,’ he said in Das Auto, ‘is the harmony of looks, handling and ride quality, which is unique and unparallelled. When motoring means not just locomotion and a streetcar substitute, the verdict of anyone who has a sense for the beauty of technical forms and elegant design of noble lineage can only be: a masterpiece.’ Unsurprisingly, these great cars were sought after. Hans Matti’s access to Swiss customs records disclosed that a dozen 8C 2900s were imported into that nation before and after the war.

However, the record is less clear for the prototype S10 and S11models. Although we recall that at least one complete S10 prototype saloon emerged from Alfa’s wartime hiding places, these cars didn’t last long – though some of the prototype engines survived, with at least three V12s circulating in the classic-car world. One was fitted to a 6C 2500 chassis with a body simulating the epic 1938 sports-racing style of Carrozzeria Touring. This was the handiwork of resourceful Emilian coachbuilder and craftsman Gianni Torelli.

Passing through the hands of Mario Righini and Dieter Dambacher, another V12 reached Milanese collector Corrado Lopresto. He commissioned the aforementioned Torelli to restore the V12 to life. This he did with vigour, fitting three-carburettor manifolding and claiming 200bhp at 5000rpm for the result. As in the other project, Torelli equipped it with a gearbox so it could be installed in a 1939 6C 2500 coupé by Castagna, a fortunate choice as this was a favoured Alfa coachbuilder with links to volume-producer Budd.

Another V12’s travels were more peripatetic, remaining at Melzo with other Alfa artefacts including 150 truck chassis. On an early post-war visit Jean Studer, a garage owner in Bern, saw these and the potential for a deal. Working through the Alfa Romeo branch in Bern he found a buyer for the chassis in the Swiss Postal Service, which needed them for vans. Studer also took a Touring-bodied 8C 2900 and an S10 SS V12 engine.

Having raced that Alfa 8C 2900 with some success, in 1948 Studer sold it to his friend Paul Glauser and bought himself another 8C, serial 412013. Wearing unique shapely roadster coachwork of 0.9mm Duralumin alloy, its distinctive style suggested that it may have been created by the wartime Alfa team at Ameno, but we do know that at least one such chassis was bodied by Bern’s Walter Martin and he may be the author of this design. Either way, this marks the arrival of our subject car, at that stage still housing an 8C engine. Studer certainly considered powering 412013 with his prototype S10 SS engine but decided that it needed too much attention.

After a brief racing career in its 8C 2900 format, Jean Studer sold Alfa 412013 to Fritz Künzi, a friend of prominent Swiss racer Willian Peter ‘Willy’ Daetwyler. Studer also parted with the V12 engine. Years followed in which serial 412013 was raced in Switzerland and then lodged with first German and then Swiss interests, the latter being the classic-car collection of Swiss polymath Pierre Strinati. A photo of its grille graced the cover of his 1968 catalogue of the collection, Voiturobjets.

A confused period followed, still in Switzerland, between collector Albert Obrist and Berne dealer in classics Albrecht Guggisberg. Some horse trading between German interests and Alfa Romeo led to the splitting up of the car’s entities. A German enthusiast brought the car’s components together again and passed them to an American collector, who had them stored in Munich.

Exactly when car and experimental V12 engine were first mated remains a mystery, but the unique sports car came to light again recently in the ownership of Swiss enthusiast Stefano Martinoli and his Progetto 33 AG. Martinoli entrusted its mechanical renaissance to Austrian restoration specialist Egon Zweimüller and the preservation of its body to Dino Cognolato’s workshop in Vigonza, near Padua, while Franco Rodighiero revived the Veglia-Borletti instruments.

Switzerland-based Progetto 33 named the car ‘12C Prototipo’ in recognition of its survival as evidence of the engineering and racing ambitions of Alfa’s Ugo Gobbato, Bruno Trevisan, Wifredo Ricart and Gioachino Colombo. Their efforts and those of the restorers are described and illustrated in a new book about the 12C Prototipo [inset, right]. As mentioned at the start, because the great Gioachino Colombo was one of the engineers who worked on the S10 and S11 engines, much has been made of the possible link between this Alfa S10 V12 and Enzo Ferrari’s seminal V12 of 1948. There are certainly similarities: the 60. vee angle (an obvious choice for a V12 engine), the diagonal split of the connecting-rod big ends (in some versions) and the use of a single triple-roller chain to drive the single overhead camshafts. Otherwise, however, the engines appear to have little in common. Obviously the Alfa as first formatted was more than twice the first Ferrari’s size, but there are also numerous technical differences. For example, piston designs are quite dissimilar, with a much heavier crown on the 125 than on the S10, while the valve-gear and the combustion chamber design of the two engines are completely different. There are many more disparities, sadly.

What we can say is that Alfa Romeo’s S10/S11 project was an ambitious effort for its era. Had the war not intervened, these cars could have vaulted into the upper reaches of the road-car pantheon. Both compact and designed for economical production, Bruno Trevisan’s 3.6-litre S10 V12 was a canny conception that could have been of great value to Alfa. The reality, however, was that Alfa Romeo never afterwards thought of producing a car with more than eight cylinders. To be sure, eight had proved more than adequate when Vittorio Jano was in charge.

Clockwise, from facing page 12C wears its scars with pride; chassis 412013 driven in 8C form by former owner Jean Studer in the 1949 Rheineck-Walzenhausen hillclimb; V12 engine has few commonalities with Gioachino Colombo’s Ferrari engine. Facing page and above Chassis 412013’s unique Duralumin bodywork is especially distinctive from the front, thanks to its cloverleaf-style grille; the one-off Alfa captured on camera in the 1940s.

‘YEARS FOLLOWED IN WHICH THE V12 WAS RACED IN SWITZERLAND AND THEN LODGED WITH GERMAN AND SWISS INTERESTS’

‘THE PROTOTYPE S10 AND S11 CARS DIDN’T LAST LONG, BUT SOME OF THE ENGINES SURVIVED – INCLUDING AT LEAST THREE V12S’

‘TREVISAN’S V12S HAD BEEN BROUGHT TO LIFE. POST-WAR RECONSTRUCTION SUGGESTS THAT FOUR WERE MADE’

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