Sorting out the Bugatti Types

J. Lemon Burton’s Talk before the North London E.C.C.

N March 24th last, J. Lemon Burton gave an interesting address to members of the North London E.C.C., on the subject of Bugatti cars. He opened his talk by remarking that as early as 1907 Ettore Bugatti designed a fairly-normal small car for Mathis and that there is an example in a museum in Paris. Next came the Type 13 eight-valve 1.3-litre Bugatti, of 65 by 100 mm., of which Burton owned a 1913 example, now beautifully restored by Peter Hampton. After removing the o.h. camshaft of these advanced little engines it was possible to withdraw a valve from the block complete with its valve seat.

After reference to the four-cylinder 16 valve Type 22 and. Type 23 Bugattis, Burton discussed the 2-litre Type 30 and Type 35 straight-eight cars. The Type 35 G.P. had roller big-ends and five-bearing crankshaft running in three ball-races and two roller-bearings, but the 35A, known as the “Artificial G.P.,” was simplified by the use of plain big-ends and three ball-race mains. Next came the beautiful little four-cylinder 1 1/2 litre Type 37 G.P., with plain bearings throughout, not raced much by the works, possibly because of its plain bearings (or because it was never intended to be raced), but said Mr. Burton, nevertheless very fast. He recalled a lap-speed of about 110 m.p.h. in the 1927 Gold Star race at Brooklands. (Actually Douglas’ Type 37 lapped on that occasion at 96.71 m.p.h., but Staniland’s 37A ultimately lapped at nearly 122 m.p.h.) 1926 saw the advent of the straight-eight 60 by 88 mm. cars, Types 38, 38A, and the 1 1/2-litre 60 by 66 mm. Types 39 and 39A, the “A” referring to the supercharger. They required to be kept at 6,000 r.p.m., the short stroke impaired the breathing, so that even when supercharged, power was limited. The 2-litre roller-bearing G.P. Type 35C, with supercharger beside the cylinder block and the famous aluminium-spoke wheels, appeared in 1927 and, said Burton, could do its 130 m.p.h. The following year the 35T appeared, but Burton has seen only one in this country; it was the 35C sans compressor, and with a 100 mm. stroke, giving a capacity of 2,261-c.c. More popular, indeed the Bugatti on which so many famous drivers began their careers, was the Type 35B, or supercharged version of the 35T, of which some 40 or 50 must have been imported into this country. The 37A was the blown version of the Type 37 1 1/2-litre four-cylinder, these cars having the same chassis as the 35, but wire wheels and bigger brakes. The Type 40 was the touring version of the 37 and able to do 75-80 m.p.h., excellent for an inexpensive car.

In 1927, too, Bugatti introduced the Type 48 “2.3” sports model, with the same supercharged, roller-bearing engine as the racing 35B. Good ones did a genuine 100 m.p.h. That year, too, Ettore offered the straight-eight 3-litre Type 44, comprising, in effect, two 1 1/2-litre cylinder blocks on a common crankcase; 20 m.p.g. and 80 m.p.h. was realised; 1929 saw the advent of the 5-litre, 81 by 130 mm., Type 46, a straight-eight of 5,350-c.c., intended by Ettore to be a quiet car, but, although capable of 80 m.p.h., not so quiet as a Rolls-Royce or Daimler, Burton admitted. The back-axle had to be removed and the crankshaft taken out before you could inspect the valves, but then Bugatti allowed 30,000 miles, say two years’ motoring, between each £75 “decoke” and, Burton said, as usual Bugatti was right.

Burton referred next to the 16-cylinder 3-litre with two banks of eight 60 by 66 mm. cylinders and geared-together crankshafts, the Type 47 introduced in 1930. Intended for Le Mans, the blower was at the back of the engine, but the crankshaft pinion gave trouble and nothing came of this car. Burton tried to buy it, but Roland Bugatti politely refused to sell. The 44 bored-out to 72 mm. became the Type 49, with alloy wheels having integral brake drums. Burton said he used one to tow his racers about and to-day Sam Clutton considers it the finest car he has ever had.

Ettore evolved next the 86 by 107 ram. 4.9-litre supercharged Type 50, with twin o.h. camshafts. Destined for Le Mans, it proved a dangerous car, with much forward weight and a wood and canvas body, and crashed badly. So Bugatti re-introduced it as a sports saloon, merely replacing the knock-on hubs for bolt-on, this being the Type 50T. Burton estimated that six or ten were built and two came to this country.

In 1931 a 72 by 100 mm. double-plug version of the four-cylinder 69 by 100 mm. Type 40, the 40A, was announced, but Burton has encountered one only, in Paris. Obviously, it used one block from the Type 49 engine. About the same time the 5 litre 46 was given a supercharger, merely to improve its acceleration, and became the 46S. There is one in this country.

The Type 35B now underwent a most significant change and re-emerged as the supercharged Type 51. The twin o.h.c. valve arrangement replaced the single o.h.c. and three valves per cylinder of all the previous cars from Type 30 to Type 49, and the odd firing order previously employed was conventionalised by re-keying the built-up crankshaft — probably to get smoother running at the increased r.p.m. of the twin-cam engine. The head cooling was improved, but speed not greatly increased, although 6,000 r.p.m. was the habitual engine speed. From the 51 came the 51A, which was the 1 1/2 litre, or 60 by 66 mm. version.

Ettore’s next production was the racing Type 54 86 by 107 mm., 4,840-c.c. job, but it proved a killer, only Varzi and Froy being able to hold it and then only up to 130 or so m.p.h. The weight again, was too far forward. Now Bugatti never wasted parts, as the foregoing will already have suggested, so he put what was virtually the Type 51 blown “2.3” engine into the chassis intended for the Type 54 and there resulted the Type 55, one of the world’s most potent sports-cars. Ettore then sought to use up the Type 54 engines and the result was the Type 50T, or blown 4.9-litre tourer, aforementioned. The famous Type 57, twin-cam 3.3 litre completed the pre-1939 range. Introduced as a beautiful 90 m.p.h. car with dog-change gearbox, it was developed into the 57T with raised axle and compression ratios for T. T.-type races, as the 57S with the raised compression ratio and de Ram shock-absorbers and shorter chassis, and. as the 57SC with supercharger, stronger clutch, etc. Finally, in 1938 came the 57C, a normal 57 mit compressor, giving great acceleration with no appreciable blower noise. The water-pump of the 57S gets rather too warm, being beneath the off-take of the exhaust manifold.

Since the war there have been a four-cylinder 350-c.c. engine with 1-inch diameter pistons, a 1 1/2-litre supercharged twin-cam four-cylinder with the startling departure from Bugatti practice of a detachable-head, and rumour of a 4.5 litre to fulfil the functions of the 57. An experimental 3-litre supercharged racing car with 3-inch diameter induction system and deep chassis side-members has apparently also been constructed. Burton said the head of the 350-c.c. engine comes off with valves intact and you put it in your pocket; he also regretted the use of normal bolts in place of the former Bugatti pattern with integral washer.

Reverting to pre-war, naturally Burton dwelt on two cars of his own, the Type 59 “3.3” G.P. racing car and his present 12 3/4-litre Royale. The G.P. “3.3” had those beautiful wheels in which the brake drums drove the rims via serrations and the “piano-wire” spokes merely located the tyres, and fully-floating rear-axle half-shafts, unusual for Bugatti. Four of these cars came to this country and one of them is now in South Africa. Burton raced the ex-Eccles’ car, which had hydraulic brakes incorporating external Lockheed cylinders. At one time, increased in capacity to 3.8 litres, it held the Class C lap-record for the Brooklands’ Campbell circuit, at 69.28 m.p.h. His Royale, Burton told us, was impressive for its entirely effortless acceleration from 10 to 60 or 70 m.p.h. and it does 80 m.p.h. in the direct second gear of its three-speed box. It is shod with 7.50-24 Dunlops, which Burton obtained by purchasing two guns so shod and then throwing away the guns! In answer to a. question he said the normal m.p.g. is eight, sometimes falling to five. The single American-looking Bugatti carburetter has controls, operating via universally-jointed shafts, for foot and hand-throttles, main-jet setting, throttle-stop and air supply. You rather feel that one push on the throttle represents half-a-gallon, but the car is certainly a museum-piece. Reverting to the “works” 3-litre G.P. cars of 1938-89, these became the 4.7 litre of the sort Wimille brought to Prescott before the war.

Pressed to continue his talk, Burton sketched briefly his own career. While at school he built a motor-cycle with aeroplane engine that did a timed 75 m.p.h. — he was disappointed, as he thought it was doing 135 m.p.h.! He next bought a rather spent Brescia for £14. After a wheel had collapsed he persuaded his father to buy him a Type 37 and, finding life rather dreary without a blower, later acquired a new 37A. He also experimented with a Type 44 engine in a G.P. chassis, but discovered, as Bugatti had before him, that too much weight too far forward in a light car renders it uncontrollable. The engine had a 12 to 1 compression ratio and blew-up in a big way at Lewes. The remains were sold to K. W. Bear, who did very reasonably with it, having plenty of spares and, maybe, a trick of his own, said Burton. He felt that with a single-figure compression-ratio reliability might have been better. With a Type 51, Type 51A, and his “3.8” G.P. car, etc., Burton gained many notable successes at Brooklands and elsewhere. Answering many eager questions, he said that he made a practice of re-rollering Bugatti racing engines every two seasons, or after about 300-500 miles of high-speed work. This was purely a precaution. The Type 43 engine was said to be safe for 30,000 miles before its solid rollers (of the later models) called for replacement, but Brixton Road made a point of examining them at each “decoke” at 10,000 mile-intervals, and if there was the slightest sign of up and down movement (a thousandth of an inch was the limit), they were re-rollered. In answer to another question, Bugatti had tried i.fs. and discarded it as no improvement over his tubular axle.

So concluded a most interesting talk and this brief resumé, with a few embellishments of our own, should satisfy the many readers who have been pressing Motor Sport for an explanation of the different Bugatti types. Incidentally, we asked Burton whether such Type Numbers had been invented by the English or whether they were recognised at Molsheim and he told us that the latter is quite definitely the case.