Maserati Tipo 61 'Birdcage'


 
Tipo 61
Years of construction 1959-1961
Two-seater sports car
3-litre 4-cyl in line
Two overhead camshafts with two valves per cylinder
Engine cubic capacity - 2890cc
Bore 100 mm x Stroke 92 mm
Compression ratio - 9.8:1
Induction by 2 Weber 48 DC03 carburettors
Power output - 250 bhp @ 6800 rpm
Weight - 600 kg
Top speed - 285 kph
17 models constructed
No cars exported to the UK
BACK

The original production run of six Tipo 60s, purchased by American customers, was followed by requests for a 3-litre model to participate in Formula 3000 events.

Due to the many enquiries from the US in regards to a larger engined version, Orsi agreed to let Alfieri develop a 3-litre engine. This increase in displacement (to 2890 cc) gave rise to the Tipo 61 and its production was totally absorbed by the US market, thanks to the Camoradi Team and its drivers.

Fitting it to the confined engine bay of the 60 was the main challenge. Eventually the Tipo 61 emerged, and the engine had a displacment of 2890cc. The weight penalty for the extra performance was minimal, but compared to opposition 3-litre class, there was a significant saving on the scale of approx. 190 Kg in weight giving a highly favourable weight-to-power ratio of 2.92 kg/bhp.

In 1961, the Camoradi Team entered the World Sportscar Championship, piloting the Tipo 61 to victory in Cuba (Moss) and at the Nürburgring (Moss-Gurney) and finishing well in the other races.

Based on these encouraging results, Maserati decided to make some aerodynamic modifications with a view to the 24 Hours of Le Mans, but the results, unfortunately, were disappointing. Then in 1961, the Birdcage was victorious in the 1000 kms of Nürburgring (Casner-Gregory) and at Rouen (Casner). The last great traditional model (front-engined and rear-wheel drive), the Maserati Birdcage left an important mark because of its refined technical solutions. Total production of the Birdcage in- cluded 17 Tipo 61s (2890 cc engine).
In 1959 Maserati startled the racing world with a new sports car of stunningly unorthodox design. Its Type 60 and Type 61 models were the fastest of their era and are still winning races today. By the end of the 1950s the front-engined racing car was dead or dying. In Formula 1 the mid-engined Coopers and Lotuses were winning. Sports-racing cars from the same makers were changing to engines behind their drivers as well and enjoying success as a result. In the midst of this debate a car appeared that challenged the trend to rear engines: the brilliant and immortal ‘Birdcage’ Maserati. The creation of the ‘Birdcage’ was evidence, if that were needed, of the astonishing resilience and creativity of the Officine Maserati of the later 1950s. This was the company that had created the 250F Grand Prix car that had helped Fangio to his 1954 and 1957 world championships, the beautiful and successful 300S sports-racing car and the awesome 450S V-8 sports car of 1957. A magnificent V-12 engine had also been created for the 250F. But this prodigality of technical innovation came at a price: by the end of the 1957 season Maserati’s finances were in a parlous state. In 1958, operating under government administration to protect its financial integrity, the Modenese firm devoted more attention to its GT car production to help restore its cash flow. Its sports-racers 300S and 200SI continued to serve their private owners. In October 1958 Maserati’s chief engineer Ing. Giulio Alfieri began considering the creation of a new sports-racing car that could compete in the international two-litre class. He had some radical ideas for the configuration of such a car; in November he was ready to start making the first chassis frame to see how well it would perform. Its tests proving satisfactory, Alfieri and his colleagues completed the design of the new car. Early in December the design and its potential were presented to Maserati’s chief, Omer Orsi, and Orsi gave Alfieri the go-ahead to build a prototype of the car. By May 1959 the first unpainted 2-litre Type 60 Maserati was ready for testing in the hands of chief mechanic Guerrino Bertocchi. He used the public road leading from Modena towards Verona and found the new car to be very satisfactory. Its next test was at the Modena Autodromo on 19 May, with Stirling Moss at the wheel. Moss then tested it at the Nürburgring from 4 through 6 June. He broke the lap record there for 2-litre sports cars and had useful suggestions for the car’s improvement. The Englishman suggested Maserati that they enter the car in a race for 2-litre sports cars at Rouen on 12 July 1959. There he easily defeated the Type 15 Lotuses of Alan Stacey and Innes Ireland. Odd-looking though it was, with its bulging fenders and trelliswork dash panel, the new Maserati was blindingly fast. Moss had already suggested to Alfieri and his engineers that they had in the 2-litre Type 60 the basis of a car that could compete in bigger leagues, and they took up this recommendation. They enlarged its four-cylinder engine to 2.9 litres, beefed up the drive train to suit and thus created the Type 61, a sports-racing car that soon showed that it could take on and defeat the best that its rivals could offer at a time when sports-racing cars competed internationally to a 3-litre displacement limit. Stirling Moss was at the wheel for its first victory in Havana, Cuba in February 1960. The striking feature of the ‘Birdcage’ Maserati that won its nickname was its chassis frame made of many small steel tubes welded together to form an elegant and idealised ‘space frame’. Although obviously complicated, the frame concept by Ing. Alfieri was in fact based on a completely logical premise. The premise was that the more frame tubes you use, the smaller they can be and, if they’re properly placed, the lighter the structure will be for the same stiffness C or the stiffer it will be for the same weight, if that’s what the designer is trying to accomplish. The ultimate would be a near-infinite number of tubes of near-infinite thinness: a smooth, complete skin. In other words, a pure monocoque structure. The ‘Birdcage’ represented the closest possible approach ever achieved to a monocoque through the use of steel tubing. Lacking experience in monocoque construction, but having on hand craftsmen superhumanly skilled in the use of welding torches, Ing. Alfieri decided to get the same effect with a myriad of chrome-molybdenum-alloy steel tubes. The closest previous approach to such a construction had been the Mercedes-Benz 300SLR of 1955, which also had a complex and rigid space frame made of many small-diameter tubes. The main framework was formed from 20 mm tubes, which were diagonally braced by smaller tubes around 12 mm in diameter. Where convenient and helpful the frame was strengthened by welding in steel sheet that helped strengthen it. This was done along the front-wheel houses and under the front end. Stressed sheet was also added along the floor pan and over the door sills and propeller shaft tunnel, where there were fewer frame tubes. The original Type 60 frame was impressively light at only 30 kilograms. ‘Birdcage’ drivers testified to the impressive feeling of stiffness that this construction provided. US-resident Swiss driver Gaston Andrey, who drove one of the first Type 61s at Nassau in December 1959, reported that it had a feeling of rock-like rigidity that he’d never experienced before. In his selection of the Type 60/61’s dimensions of track and wheelbase Alfieri relied on principles that had been proven in the last to equate to good handling. The new car’s key parameters were identical to those of the 200SI and, indeed, of the short-lived 150S: 2,200 mm wheelbase, 1,250 mm front track and 1,200 mm rear track. The Type 61 had 110 mm less wheelbase and 50 mm less track than the 300S which it effectively replaced reductions which contributed to the 200-kilogram margin of lightness between the 300S and the Type 61, which had a remarkably low dry weight of 570 kilograms. To lower both its hood line and its centre of gravity, the new car’s four-cylinder in-line engine was canted over 45 degrees to the right. At the same time the crankshaft centreline was offset to the left side of the chassis, to keep the engine’s weight centred. This required the propeller shaft to angle back to the right again as it ran rearward only slightly, because the input shaft to the rear-mounted gearbox was also offset to the left. This left proportionally more room for the driver on the right-hand side of the drive shaft. The Type 60/61’s engine was derived from that of the 200SI, which in turn had been developed from the 150S. Most closely related to its forebears was the aluminium-alloy cylinder block, which housed wet nitrided-iron cylinder liners and which carried the crankshaft in five main bearings. In the design of the crankshaft, connecting rods, pistons the similarly-proportioned 450S V-8. With its single cylinder head placed at the precise angle of the right-hand bank of the 450S V-8, the Type 60/61 engine could well afford to keep this new form of water manifolding. An additional major change from the V-8, moreover, was the abandonment of the elaborate roller-finger cam follower that had come in with the 150S and had spread to the 200SI and 450S. For his new engine Alfieri reverted to the simple, light, space-saving finger follower that had been proven on all the Maserati twin-cam sixes. In the latter engines it was combined with coil springs, while in the new engine it worked with hairpin-type springs for the first time. Weber 45 mm twin-throat carburettors were used on the Type 60 engines, protruding high up from the hood to get the straightest possible air-flow path into the ports. On the Type 61 the carburettors (48 or 50 mm) were angled downward under a more modest hood bulge. The dimensions of the 1.5-litre 150S four-cylinder engine had been 81 x 72 mm and those of the 200SI 92 x 75 mm. The Type 60 engine was made more oversquare at 93.8 x 72 mm. It produced 200 bhp at 7,800 rpm, up from the 200SI’s 186 bhp at 7,500 rpm. To enlarge the engine to power the Type 61 the bore was increased as much as the block and liners would allow to 100 mm and the stroke increased to 92 mm for 2,890 cc. Achieving the latter required the casting of a new cylinder block 10 mm taller. An attempt to lengthen the stroke to 95.5 mm to bring the displacement to 2,985 cc failed when the test engine destroyed itself on the Maserati dynamometer. With a compression ratio of 9.8 to one, the Type 61 engine produced 255 bhp at 6,500 rpm. Its torque reached a maximum of 31.6 kg/m at the 5,000 rpm peak of a very strong torque curve that gave the engine great flexibility. Ing. Alfieri transmitted this through a multi-plate clutch in unit with the engine and an engine-speed propeller shaft to the rear-mounted transaxle that had been a Maserati feature since it was introduced on the 1954 Grand Prix car. Using this transaxle meant that Alfieri could also keep the De Dion rear suspension that was introduced on the 250F at the same time. It axle tube ran forward of the gearbox and was laterally located by a steel-sided slide in the front of the transaxle casing. Parallel trailing arms guided the wheel hubs individually. Separately mounted, on drilled webs, were tubular shock absorbers. Initially Girling dampers were used but later Konis were more common. An utter novelty for Maserati was the use of a rack and pinion steering gear, mounted ahead of the front wheel centres. The front suspension drew directly from the Viale Ciro Menotti parts bins: it used components from recent Maserati Grand Prix cars. The wishbones were parallel, with the top arm substantially shorter than the bottom one. They and their concentric coil-damper assemblies were hung from drilled pylons very much like those used on the ‘Piccolo’ Maserati G.P. car of 1958. The Type 60/61’s brakes marked a major step forward. Maserati took up an experimental Girling design featuring an unique three-cylinder caliper. The front discs were 355 mm in diameter and those in the rear 315 mm. Separate brake master cylinders for the front and rear circuits allowed front/rear braking proportioning to be adjusted as required. These disc brakes proved ideal for stopping this light and fast racing car. Sixteen-inch Borrani wire wheels with 42-inch duraluminium rims were fitted at all four wheels. Normally the tyre fitting was Pirelli Stelvio with 5.50 x 16 tyres at the front and 6.50 x 16 Pirellis at the rear. Some cars were shipped to America, however, with 5.50 x 16 D5 Dunlops on the front wheels and 6.00 x 16 rear Pirellis. The very low and compact build of the Type 60/61, with its body wrapped tightly around the wheels, was an asset to its speed. The efficiency of its shape had been verified by Alfieri with clay models tested in Maserati’s wind tunnel. Claimed were top-speed capabilities for the small and large ‘Birdcage’ versions of 270 and 285 km/h respectively, figures which were closely approximated using high final-drive ratios. Under racing conditions they consumed about 40 litres per 100 kilometres from a 120-litre fuel tank. The ex-factory price of a new Type 61 Maserati was the lire equivalent of $10,800. By the time an American customer had paid for freight and duty he would have spent some $12,000. A customer in Europe might have paid as little as $9,000 for his car; the price to an authorised Maserati distributor was $8,000. The average revenue per car received by Maserati from the sale of the first 21 ‘Birdcages’ (22 in all were made) was $11,800. This of course included the profitable sale of spare parts for these cars. Not surprisingly, early races revealed some durability faults in this advanced car. Two cars broke their de Dion axle tubes at Nassau at the end of 1959; a new stronger design was produced and retrofitted. After failures at Sebring in March 1960 the rear hubs were strengthened and the main bearings were increased in diameter from 60 to 65 mm. Thus revised, the Type 61s raced in North America had many successes. They were used to win the SCCA’s Class D Modified championship, for 3-litre sports-racing cars, by Gaston Andrey in 1960 and by Roger Penske in 1961. Drivers such as Jim Hall, Bob Drake, Walt Hansgen, Jim Jeffords, John Fitch and Carroll Shelby raced them with great success for private teams. Billy Krause used one to defeat all comers, including Stirling Moss in a mid-engined Lotus 19, at Riverside in October 1960. Although the very fast ‘Birdcages’ easily led all the international events they entered, their record of success in these was spotty. In 1960 and 1961 the international race entries were made by an American team, Camoradi USA, founded by Miami, Florida car dealer Lloyd ‘Lucky’ Casner. Camoradi owned the cars, engaged the drivers and made the race entries, while Maserati took care of preparing the Type 61s. With drivers such as Stirling Moss, Dan Gurney, Carroll Shelby and Masten Gregory, Camoradi seemed to be well equipped for the 1960 season. The finances of neither Camoradi nor Maserati could extend to thorough testing of the new cars, with the result that in long-distance races they often suffered retirements for various reasons. They brought a superbly-streamlined Type 61 (actually the original Type 60 rebuilt) to Le Mans in 1960 for Chuck Daigh and Masten Gregory. It easily outpaced all other competitors both in practice and the race but retired. A noteworthy and noble exception to this record was the performance of the Type 61 at the Nürburgring. There in the 1,000-kilometre race the Camoradi ‘Birdcages’ were successful in both 1960 and 1961. In the first year the driver pairing was Moss/Gurney, one of the greatest of all time, and in the second year the victory went to Masten Gregory partnered by ‘Lucky’ Casner himself. In all, 22 ‘Birdcage’ Maseratis were produced. Eleven were made in 1959, seven of them Type 61s. In 1960 nine were produced, only two being Type 60s. Two final Type 61s were made in 1961, together with five new engines to service the teams running the cars that season. Beautifully-balanced, well-braked, easy to steer and immensely satisfying to drive, the Type 61 ‘Birdcage’ Maseratis are still giving their owners great satisfaction in vintage racing in all parts of the world. Fortunately that gives today’s car enthusiasts the chance to see a Maserati that was, in its day, clearly the fastest car of its kind. That’s a Maserati tradition well worth recognising.