Immorality Clause

Unfettered by the rules of contemporary Grand Prix racing, Scuderia Ferrari’s Bimotores were designed to tackle some of the highest-speed races of the mid-1930s.

Photo: Immorality Clause 1
October 27, 2016

Enzo Ferrari boasted proudly, said one of his engineers, of his “immoral” actions. He wasn’t referring to his private life—although in this he was not entirely without reproach—but his knack for marriages of racing-car components that broke the rules and created new kinds of cars from the raw material available to him. One of his first such immoral projects stunned the racing world in 1935.

Ferrari had several points to prove. A decade earlier he had given up a moderately successful career as a racing driver to concentrate on his responsibilities at the great Milanese automaker Alfa Romeo. There, he acted as the right arm of Giorgio Rimini, a senior aide to company chief Nicola Romeo. Ferrari also enjoyed his role as the Alfa Romeo distributor in Modena.

However, Ferrari, in his own words an “agitator of men,” had another idea. It matured at a dinner in the company of Augusto and Alfredo Caniato, textile-making brothers and enthusiastic amateur racers from Ferrara. Joined by Mario Tadini, the Caniatos in 1929 gained the backing of Alfa Romeo and tiremaker Pirelli to set up Ferrari as the chief of a private racing team: Scuderia Ferrari (scuderia simply meaning “team”). At the young age of 31, Enzo Ferrari was ready to put wheels under other drivers.

Soon a capacious headquarters and workshop was acquired on Modena’s Viale Trento e Trieste, headed by able and experienced mechanician Luigi Bazzi. The Scuderia attracted seasoned pilots Achille Varzi and Tazio Nuvolari, as well as numerous amateurs, and entered both sports and Grand Prix Alfa Romeos in races major and minor. Ferrari’s main rivals were not only the agile cars of Ettore Bugatti, but also the maturing products of the Maserati brothers.

Although Enzo had excellent relations with Alfa Romeo, the automaker only erratically delivered examples of its top racing machine, the central-seat Type B, to him. Seeing few chances to win, Varzi defected to Maserati during the 1930 season; Nuvolari followed three years later.

But Ferrari’s Scuderia had evolved into an engineering-racing division of Alfa Romeo, and that same year Enzo took over Alfa’s competition function entirely. This more businesslike orientation led to the interests of the founding Caniatos being bought out by Count Carlo Felice Trossi (a great personality as well as a driver of considerable merit).

Photo: Immorality Clause 2

With the arrival in 1934 of new Grand Prix rules requiring cars to weigh no more than 750 kilograms (1,654 pounds) without tires and liquids, Alfa’s Type B was at first competitive. Soon, however, it was swept aside by advanced new creations from German carmakers Mercedes-Benz and Auto Union. Though the brilliant engineer Vittorio Jano had started work on a new Alfa, in the meantime the best had to be made of existing machinery. This meant enticing Italy’s best driver back to Scuderia Ferrari.

Tazio Nuvolari had been doing well with Maserati, which had its own new car in the wings. What could lure him back to Enzo’s team? Enter an “immoral” idea: an Alfa Type B with one engine in the front and another in the back.

THIS UNUSUAL CONCEPT is credited to Luigi Bazzi, who put it to his chief at the Scuderia’s annual dinner in December 1934. While the proposed car wouldn’t be eligible for Grands Prix due to its weight, there were other events, such as the Avus in Berlin and the “Race of the Millions” at Tripoli, which offered lucrative prize money and were run to more liberal rules.

Aided by draftsman Arnaldo Roselli, Bazzi laid out his vision. The Type B Alfa was uniquely suited to such an adaptation. Instead of using a conventional central driveshaft to its rear axle, the car had in effect two such shafts, splaying to the left and right from a differential located directly behind the gearbox. Each rear wheel was driven by its own ring and pinion, which left a gap in the middle where the back engine could go.

The drive would be taken from the front end of the rear-mounted engine. A shaft would go forward, through the center of the transmission mainshaft, to the same clutch unit that was driven by the front engine. Then the torque generated by both engines would be sent back through the gearbox to the differential, from which it would reach the rear wheels via the Type B’s unique axle system. On the shaft entering the gearbox, a dog clutch engaged the shaft from the added engine. At the latter, a rubber torsional joint to the shaft smoothed out rotational fluctuations between the two engines. It was an extremely clever way to make the two engines work in unison.

After explaining their plans to Vittorio Jano—who in 1931 had built an Alfa Romeo with side-by-side front-mounted V6 engines, the Type A—Ferrari and Bazzi were granted approval to proceed. They laid down two cars to their radical design. Both were given the new independent front suspension Scuderia Ferrari was already adapting to its Type B racers, which used the French Dubonnet system with enclosed coil springs that were carried outboard of the steering knuckles.

Photo: Immorality Clause 3

Bazzi found he would have to lengthen the Type B’s wheelbase and frame by only 15 centimeters (5.9 inches) to make room for the rear engine. Taking advantage of the separate driveshafts to the rear wheels, the Modena team introduced universal joints that allowed the wheels to move independently. Each wheel hub was guided by a U-shaped member that was pivoted from the frame and sprung by a semi-elliptic leaf and two powerful friction dampers. This adoption of swing-axle rear suspension improved drive traction and allowed the rear engine to be placed lower in the chassis. More problematic were the changes in camber that resulted from wheel movement, affecting the car’s handling.

The standard Type B gearbox would wilt under the strain of having to cope with twice the power, so Bazzi and Roselli addressed this issue with a difficult compromise. They widened and strengthened the transmission’s gears, but to make room they had to eliminate one of the unit’s four ratios. Three speeds weren’t ideal for a car that would be much faster than the Type B, but they estimated it would be adequate for racing on the very fast Tripoli and Avus circuits.

As in the twin-engine Type A, the cooling radiator was divided in half: one side for each engine. A single 40-liter oil reservoir at the extreme rear of the bodywork was connected to the dry-sump systems of both engines. Interconnected fuel tanks sat along the cars’ flanks, giving a total capacity of 240 liters (63.4 gallons).

Such were the skills of Modena’s cadre of coachbuilders that all this machinery was enshrouded in bodywork that gave little hint of the cars’ extraordinary concept. A quick glance suggested nothing unusual about the design that became known as the “Bimotore” for its two engines. Exhausts of both straight eights were on the right side and close together.

Streamlining know-how was shown in the fitting of a head-rest behind the driver and full enclosure of the front of the frame. For the grille, a heart shape was adopted. Soon after the completion of the two cars, they were fitted with a badge that credited the Ferrari contribution. On a shield of yellow, the Modena town color, was the black prancing horse of World War I flying ace Francesco Baracca, adopted as his emblem by Ferrari with the encouragement and approval of Baracca’s parents. Many thus consider the Bimotores (properly “Bimotori”) to be the first real Ferraris.

The two Bimotores differed in their Type B motorization. One utilized a pair of 1934-season 2.9-liter straight eights, which gave a total of 5,810cc and 510 bhp at 5,400 rpm. The other had the larger 3.2-liter eights first raced in 1935, for an aggregate 6,330cc and 530 bhp at the same rpm. (Each engine had its own starting crank.) This was well in excess of anything the Germans could offer in 1935, when they were just reaching 400 bhp, but the Bimotore’s weight was higher than that of the Grand Prix cars, at 1,030 kilograms (2,271 pounds) dry, much of it resting on the 21-inch rear wheels and their Belgian Englebert tires.

Photo: Immorality Clause 4

NO SOONER HAD ENZO FERRARI confirmed his plans to build the cars with Alfa Romeo than he communicated the news to Nuvolari. Always fascinated by the latest equipment, the great Mantuan driver immediately understood the potential of the Bimotore. He agreed to rejoin the Scuderia as partner to the able Frenchman René Dreyfus and Monaco’s Louis Chiron. Announcement of Nuvolari’s move to the Modena team at the end of January 1935 brought general rejoicing, not least at Alfa Romeo.

On April 4th, Nuvolari sat on the autostrada between Brescia and Bergamo, one side of which was closed for the first trial of a Bimotore. The complicated machine had been designed and built in a scant three months, with the “small” 5.8-liter version first to be completed. Ferrari tester Attilio Marinoni warmed up the car, then turned it over to Nuvolari.

After several runs at 4,500 rpm, Nuvolari turned the Bimotore loose. Though officially timed at 175 mph over two kilometers, he said he had in fact reached a maximum of 5,300 rpm, which was equivalent to 200 mph. Furthermore, Nuvolari thought 5,600 rpm —210 mph—should be on the cards. “The Bimotore drives like a Lancia Aprilia,” he told a delighted Bazzi, likening it to Italy’s best small car.

Both Bimotores were prepared for the Grand Prix of Tripoli, covering 326 miles of the Mellaha circuit in the Italian protectorate of Libya, on May 12th. The 6.3-liter version was assigned to Nuvolari and its smaller-engined sister to Louis Chiron, who had set the fastest lap in the race the previous year at 124.5 mph. With several corners now eased, the track was expected to be even faster in 1935.

In practice, all the teams had so much tire trouble that auxiliary pits were set up on the far side of the 8-mile track to change the wheels of the unfortunate. After only two of the 40 laps this included Nuvolari, who had been racing with the leading Mercedes-Benzes. More tire stops followed for all the leading runners, though Mercedes’ Rudy Caracciola was showing the shrewd pacing that would win the race.

Let off the leash toward the finish, Nuvolari was challenging the Auto Union of Varzi, who had left Ferrari’s stable to drive for the Germans, for the lead when he had to stop again for fresh rubber. He was fourth at the finish, one place ahead of Chiron in the sister car, a second and a half ahead of Dreyfus in a standard Type B Alfa. All were on the same lap in an exciting race whose average speed of 123.0 mph was close to the previous year’s lap record.

Photo: Immorality Clause 5

The Bimotores were next readied for Berlin’s Avusrennen on May 26th. The race featured two 61-mile heats and a 122-mile final, run on a 12.2-mile circuit that consisted of two sides of an autobahn connected by loops at each end. The lap record stood at a heady 140.3 mph.

Practice times varied widely, though Nuvolari in the “big” Bimotore lapped on a par with the Mercedes-Benzes and the Auto Union of Bernd Rosemeyer, making his debut with the team and its tricky mid-engined cars. In the first heat, the Mantuan was a victim of his own impetuousness. A tire threw a tread, requiring a stop for fresh rubber on Lap 2 that knocked him out of the top four finishers who would go through to the final. Chiron did better in his Bimotore, finishing a canny fourth in the second heat.

Under the eyes of several hundred thousand Berliners, the German teams went at it hammer and tongs in the final. Now it was their turn to be hampered by tire failures, which let the red Bimotore rise through the ranks of silver cars. Chiron finished a comfortable second behind a Mercedes, which won at 148.2 mph, and ahead of the Varzi’s Auto Union. It was a more than respectable result.

After the Berlin race Nuvolari received a letter from tire magnate Georges Englebert:

Dear Signor Nuvolari,

I have had a discussion today with Mr. Gros, who has reported me the great courtesy offered by you after the incident of the detachment at high speed of a part of a tyre protector. Be confident that this misfortune is not owed to a defect of ours during manufacture, because the controls that I impose in the workshops are really severe. Any declaration from you about the cause of this would have been damaging to our interests. And for this I consider to have to thank you most sincerely. Please accept, dear Signor Nuvolari, my most sincere gratitude.

Photo: Immorality Clause 6


If the Belgian hoped his gracious gesture would secure the role of Englebert rubber on the Bimotores, he was mistaken.

The next challenge for Enzo’s “immoral” design was record-breaking. German drivers like Hans Stuck and Rudy Caracciola were regularly setting new speed records, sometimes on the autostrada under the noses of the Italians, and Ferrari, Bazzi, and Nuvolari were not about to let them stand.

The “big” Bimotore was substantially rebuilt for the new task. To reduce both weight and drag, the side fuel tanks were replaced by a small reservoir that was adequate for short record runs. Similarly, the size of the oil reservoir was diminished, helping reduce dry weight to 950 kilograms (2,095 pounds). A low-drag windscreen was fitted, together with discs to smooth flow over the wire wheels. Instead of the Engleberts, the Ferrari rolled on speed-proven British Dunlops.

Both the timing and the venue for a record attempt were carefully chosen by Ferrari and Nuvolari. The date was June 15th, the day before Mercedes-Benz and Auto Union would battle for Teutonic supremacy in the Nürburgring’s Eifelrennen. The place was the A11 autostrada between Lucca and Altopascio, a six-mile stretch on a level plain where Hans Stuck’s Auto Union had been timed at 199.01 mph in mid-February. It was time to recoup some pride for Italy.

Nuvolari and the Bimotore were on the autostrada bright and early. In spite of marked side winds, the Mantuan went straight to it after lubrication problems had been solved. His best runs were timed at an average of 199.73 for the flying kilometer and a satisfying 200.78 mph for the mile. Nuvolari’s highest one-way timed speed was 208.81 mph. There was more to come, he and Bazzi knew—the highest speed reached was some 225 mph—but several runs on the Sunday were hampered by stronger winds.

Photo: Immorality Clause 7

So pleased was the Italian champion that he tipped Bazzi 10,000 lire for his efforts. Though Nuvolari avoided being critical of the autostrada, he said it wasn’t ideal for record-breaking, especially at the speeds he hoped to reach when he had more time in his busy racing schedule. Curiously, no effort was made to set new standing-start records.

Nuvolari’s new records were well recognized in Rome a month later when, togged out in white suit, shoes, stockings, gloves, and a straw boater, the driver was awarded a gold medal for athletic achievement by Il Duce, Benito Mussolini. Though the records in Class B for cars of 5 to 8 liters weren’t hard to break—they were set by a Panhard in 1930 at 138 mph—Nuvolari was at the time the fastest motorist alive, save English speed specialist Malcolm Campbell.

NUVOLARI NEVER HAD TIME to return to the pursuit of records. The record-breaking Bimotore was set aside in the Viale Trento e Trieste workshops, and presumably later dismantled for its components, while its “little” sister was the subject of further experiments into 1936. It was fitted with better independent front suspension using trailing arms and coil springs, like that adopted for the improved Alfa Romeo Grand Prix cars. At the end of thatBeechwood Farms Nature Reserve year, the “small” Bimotore was sold to British racer Austin Dobson to take up a new career on the steep bankings of England’s ultra-fast Brooklands track.

“Many rumors were current,” wrote Brooklands historian Bill Boddy, “such as that the car was only on loan to Dobson, that certain parts were still sealed, that Italian mechanics would be coming over to service the car, and even that Dobson was distraught because the Brooklands silencers didn’t emit enough noise.” Called “beautiful,” “fantastic,” and “meteoric,” the Bimotore broke the Class B record for the Brooklands mountain circuit during the Easter 1937 meeting in spite of fading brakes.

On May Day, Dobson entered his Bimotore in the 220-mile race over the new Campbell road circuit. Though braking was again a bugbear, he held second place until transmission trouble ended his day. Later that year, the car finished fifth in the 1937 BRDC “500,” lapping the banked Brooklands bowl at a commendable 132.8 mph.

In 1938, ownership of the Bimotore passed to Peter Aitken, who entered it for several Brooklands events but never actually brought it to the track. The unique machine was such an attraction the Brooklands authorities posted a notice of any non-appearance outside the gates so ticket buyers wouldn’t demand their money back.

Aitken eventually took the drastic, and in retrospect regrettable, step of removing the Bimotore’s rear engine and fitting a conventional rear axle and preselector gearbox. The resulting “Alfa-Aitken” competed in the final Brooklands meeting before World War II, placing second in a handicap race. After the war, the Bimotore still showed form, especially when it was rebuilt by tuning expert Freddie Dixon to an unsupercharged 3.4-liter size to compete in the new Formula 1, while owned and driven by Tony Rolt.

In this guise the car was sold to New Zealand, whence it was later rescued by Tom Wheatcroft for his racing-car collection at Donington. From the parlous state in which he found it, Wheatcroft arranged for its restoration as a Bimotore by Rick Hall. A demanding five-year effort led to the revival of a running Bimotore.

“It’s a fantastic piece of equipment,” said Wheatcroft. “People can hardly believe it when you take off the covers to reveal these two whacking great straight-eight engines. The noise they make when running at full revs is phenomenal—a deep-throated roar. I have driven it with pride on demonstrations throughout Europe and it has always given me a great thrill.”

Also from Issue 154

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  • 2016 Monterey Car Week concours
  • 70th-anniversary unique liveries
  • F1: Red Bullied
  • FORZA Tifosi Challenge: F430 championship
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