1934 RACING CARS

1934 RACING CARS

No. 7.–THE 2.8 LITRE BUGATTI

IN 1932 the 2.3 double camshaft Bugatti and the 2.3 litre Alfa-Romeo enjoyed the distinction of being the two supreme European racing cars, and there was virtually nothing t() choose between them. Suddenly the situation changed, for the new single-seater Alfa which made its debut at the French Grand Prix that year completely outpaced its rival.

The reputation of the Bugatti had been built up on racing successes, and Monsieur Ettore had no intention of falling behind in the struggle for supremacy. A new and specialised vehicle like a racing car cannot be evolved in a day, but already by October, 1932, there were rumours of a successor to the ” 2.3.” The decision of the Alfa-Romeo factory not to race the Monopostos in the 1933 season gave the French factory a further breathing space, which was particularly welcome in view of the 750 Kg. weight restriction to be enforced during 1934.

Three of the new cars were entered in the Spanish Grand Prix in September, 1933, as a preliminary test, to be driven by Varzi, Dreyfus, and Wimille, but the latter crashed in practice. The two cars which ran did not seem to be conspicuously successful, finishing only fourth and sixth, while Lehoux on a ” 2.3″ came in third, over a minute ahead of Varzi.

Development continued during the winter, the principal exterior alteration being the liberal drilling of the side members. The first appearance of the cars in their ultimate racing trim was arranged for the Monaco Grand Prix. The official racing team consisted of Dreyfus, Wimille and Benoist, Nuvolari was also driving a “2.8,” but as an independent entry.

Benoist crashed in practise, damaging a back axle, which could not be replaced in time. Wimille was eliminated at an early stage through the shearing of the rivets in one of the back brake-linings, leaving Dreyfus to carry on alone. His car cornered well and was noticeably steady when braking. Its maximum speed seemed less than that of the Alfa Romeos, but this may have been due to team orders. The tactics seemed justified, as Dreyfus finished a comfortable third. Nuvolari expressed himself well satisfied

with the car in practise, and hoped to be able to lap at z min. 58 secs. during the race. On the day however, he found that he was unable to hold the car on corners at the same speed as during the practises.

With a full petrol tank the tail swung round, and the hydraulic shock-absorbers were not readily adjustable. He therefore carried on as best he could until the tank was half empty, when he regained his speed. His braking trouble was due to extra-hard use in trying to regain the time he had lost. He finished fifth.

The ” 2.8 ” Bugatti differs from all the other Grand Prix cars so far described in being nominally a two-seater. Actually of course, the oil-tank occupies what would normally be the mechanic’s seat, but by seating the driver alongside the transmission instead of on top of it, Monsieur Bugatti has achieved a low seating position without any complications. The engine specification differs radically from that of any previous model. In the first place, the crank-shaft is carried in

nine ‘plain bearings, and white-meta bearings are also used for the big-ends The cylinder head and block are both made of steel, in one unit, with two overhead valves per cylinder set at 90 degrees to one another and operated by overhead camshafts. The sparking plugs are mounted in the centre of the heads.

The camshafts are driven by trains of gears from the rear end of the crankshaft and the supercharger, which is tucked away on the off-side. of the engine is also driven in this manner. Two down-draft Zenith carburetters are bolted to the top of the casing and are protected by a gauze screen. The two throttles open in opposite directions, and are therefore linked together by a pair of toothed quadrants. The fuel is fed by pressure from the rear tank, which holds about 30 gallons.

The water pump, with the characteristic Bugatti greaser, is carried on the left side of the engine in a position corresponding to that of the supercharger.

The Scintilla magneto is driven from the near-side camshaft and projects through the dash into the driving compartment, with the rev-counter similarly driven on the driver’s side.

Dry sump lubrication is used, with a finned sump. The oil tank, which holds about 21 gallons, is carried alongside the driver, and the hot oil is cooled by passing it through a multi-pipe cooler which is mounted on the side of the chassis. The engine is started from the side, through the timing gears. The hole for the handle will be seen above the cooler, and the actual handle is kept in a pocket in the cockpit.

The familiar Bugatti exhaust system, with its bunched pipes, has given place to a close-up manifold and a large tailpipe. This is probably the reason why the familiar crackle has given place to a typical Grand Prix roar. The engine seems much longer than that of the” 2.3,” partly owing to the use of plain bearings, and is carried very low in the chassis. In outward appearance it is almost identical with that of the sports ” 3.3 ” described in last month’s issue of

MOTOR SPORT.

A multi-disc clutch is used, and the gear-box is mounted independent of the engine with a right hand gear-change. The brake-lever is, however, on the driver’s left.

The open propeller shaft has a long torque member running alongside it from the back-axle to a universal joint on the gear-box. At first sight the final drive appears to embody worm gears, for the driving-shaft comes in beneath the axle centres, but actually there is a double reduction. The ” prop-shaft ” drives a pair of bevels, and a further reduction is effected through a pair of straight pinions. This gives a compact casing and a low propellor shaft line. The flanges of the side-members are immensely deep, some 9 inches in depth in the centre of the car, tapering off in front to form the front dumb-irons, and swept over the back axle at the rear. They are very light in section, liberally drilled and braced by tubular crossmembers. The front springs—which are semi-elliptics—are pivotted at the rear and work in slides in the front end, while stiff wide reversed quarter-elliptics with a number of clips are employed at the rear. The front axle is in two pieces, with a central shouldered shaft against which the two halves butt. The outer sections are drawn together by a central nut with right and left hand threads, and the springs pass through lugs integral with

the outer sections. The track of the car is about 4 ft. 4 ins., and

the wheelbase a,ppears to be approximately 8 ft. 10 ins. Special hydraulic shock absorbers are used back and front, the front ones being housed inside the bonnet with only the arms, as usual very much drilled, projecting. The brakes are almost as large as the wheels, and are operated by

the usual Bugatti cables with chain cornpensators. The wheels are quite unique. They hive as their basis the normal tapered Rudge Whitworth hub, and to the outside extremity of this is attached an aluminium disc conical in section and furnished with serrations at the rim. The tyre is carried on a fiat-base rim, with a split outer flange which allows the cover to be changed, and made with internal serrations to engage with those on the wheel disc. The rim is held in position by two sets of spokes, one set running from the rim to

the outer extremity of the hub, while the other set pass through holes in the disc to the inside of the hub. The steel brake-drums are attached to the rear side of the disc. The new wheels are said to be TO lbs. lighter than the aluminiumspoke pattern formerly used, without any loss of rigidity.

The bodywork is the usual Bugatti type, with aluminium panels secured with wire lacing. The bonnets of the teamcars were all in one piece, made out of two sheets of metal welded together along the top line of the body where the hinge would normally be. In appearance the “2.8 ‘s” are lower and more slender than the 2.3 litre cars, and finished in a silvery blue are as attractive as anything which has ever left the Molsheim factory. Maximum speeds of 175 m.p.h. have

been suggested for these new cars, but the only official information we have received on this subject is that they have exceeded 165 m.p.h. by rev-counter, but have not yet been timed. This speed, incidentally, was put up on public roads, on the fast leg of the old Strasbourg circuit. The official team, as chosen at the beginning of the season, consisted of Dreyfus, Wimille and Benoist, with Nuvolari driving as a semi-independant in the International Grands Prix. Dreyfus has been with Bugatti for the past two years and backed up Varzi in several of

his successes, such as the Monaco G.P. in 1933, in which he was third. Wirnille as the ” independant ” driver of a 2.3 Alfa Romeo was second in the Marne and Cornminges Grand Prix last year, and will be a very useful member of the team. Benoist, who in 1926-7-8 was uncrowned champion of Europe, driving Delages, and who occupied as prominent a position as Nuvolari did last year, gave up racing at the close of 1928, but after a month of practice on Montlhery and elsewhere seemed to have recovered all his former skill. A damaged backaxle in the Monaco G.P. prevented him from driving there. A last-minute addition to the team is that of Brivio, who won last year’s Targa Florio on an Alfa, and also did well in the Bordino and Ciano races.

It seems rather paradoxical that a firm established in what was Germany from 1903 until 1919 should be the sole representative of France in the international races of the present day. Without government support Bugatti cars have until the arrival of the Monoposto Alfas held their own with credit, and the many Bugatti enthusiasts in England will join in hoping that the latest creations of Monsieur le Patron will oncemore compete on even terms with the Italian cars.