SPORTING CARS ON ROAD AND TRACK. 1,500 c.c. Grand Prix Bugatti.
By RICHARD TWELVETREES. EVER since the Bugatti made its first appearance
in this country it has been the subject of warm admiration on the part of all sporting motorists, and even if some of the early models were inclined to be a bit fickle at times, the moods were readily excused and discounted by the extraordinary fascination these wonderful little machines never failed to evoke. I have been for trips in ” Bugs” during which the good Ettore has been anathematised in no unmeasured terms, but even a spell of work with intricate little bits of machinery has never failed to damp my personal affection for his sweet little productions.
One has only to glance at the 1,500 c.c. Grand Prix Bugatti, however, to observe that it is a distinct advance on any of its forerunners, and the manufacturers have introduced a new era for the sporting motorist by placing a real production racing car in the hands of the public. That is to say, one can purchase one of these machines drive it away, and as delivered it will be fit to win races and competitions without any need of “hotting up.”
The actual car portrayed in the accompanying photographs is that belonging to Capt. J. C. Douglas, and was driven to victory by its owner in the” Evening News Hundred, as described elsewhere in this issue. Incidentally it may be mentioned that the car won that event in its ordinary touring trim, and also that it is used daily as a runabout by Mrs. Douglas for shopping expeditions in the West End, which supports the makers’ claim as to docility.
The stability of the Grand Prix Bugatti and its wonderful steadiness in cornering at speed is largely due to the very low centre of gravity, the chassis being very low without detracting too much from ground clearance. The suspension comprises semi-elliptic front springs, located outside the frame members and provided with rebound clips on the forward halves. The wellknown and tried reversed quarter-elliptic springs carry the rear axle, shock absorbers of the Bugatti design being employed for both sets of springs.
Though the seats are arranged very low, the riding is quite comfortable, and plenty of leg room is provided on either side of the clutch and gear box, this part of the mechanism being covered by a readily removable leather flap.
An Accessible Power Unit.
When the bonnet was removed for examination of the engine, I was surprised at the amount of accessibility, for from the external appearance of the car one is apt to imagine that the mechanism must be somewhat cramped. There is, however, plenty of room to get at everything, and any of the normal running adjustments can be made with extraordinary facility. The fourcylinder engine, which follows the design of the famous “straight eight” very closely, measures 69 mm. bore and 100 mm. stroke, equal to 1,496 c.c., and revs, up to well over 5,000 r.p.m. almost as soon as the accelerator pedal is depressed. The overhead camshaft gear is enclosed in a neat square aluminium cover, which, conforming with the outline of the cylinder block, gives the engine a particularly neat appearance. Both the revolution counter and the Delco distributor take their drives from the rear end of the camshaft, and immediately above these instruments is a pressure release valve, through which surplus oil from the camshaft gear is returned to a reserve tank situated beneath the driving seat.
A single Solex carburettor of large dimensions is bolted to an aluminium water jacketted induction pipe, and below this on the right hand side of the engine are the sparking plugs, which are easily accessible. At the front of the engine are arranged the centrifugal-type water pump and an unusually large pump of the gear wheel impeller variety, from which the oil is fed under pressure to the various parts through large diameter copper pipes. Special attention has been paid to the free passage of the exhaust gases, large pipes from the respective parts leading downwards to a large diameter tube. The Bosch dynamo is directly coupled to the forward end of the crankshaft, and is located low down in the frame.
The general appearance of the car is greatly enhanced by the narrow Grand Prix pattern radiator, which, though narrow, is of deep section, and presents ample cooling surface.
The old transmission brake has been discarded, and the hand lever operates a special set of shoes in the rear wheel drums.
A fully floating rear-axle is employed, with an exposed cardom shaft, but the torque reaction is resisted by ball ended radius rods, attached at their forward ends to the outside of either side member of the chassis.
Thanks to the 7ft. 10iin. wheel-base, and a track measuring 3ft. 11-&in., together with a very good steering lock, the Bugatti can be negotiated with ease in confined spades, and is therefore very handy for competition work as well as flat out racing.
Impressions during Road Test.
I was fortunate in being able to see the best of this attractive little sports model in really expert hands, for Capt. J. C. Douglas is certainly amongst the topnotchers of demonstrators. I had expected to be
Clutch and Transmission Details.
The drive from the engine is transmitted to the gear box by a multi-disc clutch of the metal to metal variety, which is rapidly regaining popularity for fast cars at the expense of the single plate type. A separate fourspeed gear box, with a minute gate charge, provides ratios especially suited for high speed driving on track and road, which are as follows :—First speed, 7.5. to 1 ; second speed, 6.5 to 1 ; third speed, 5 to 1 ; and top speed, 4 to 1. The change speed lever passes through a slot in the side of the driving scuttle, the slot being shielded by a flexible leather flap.
As befits a model with such a noteworthy speed performance, the Bugatti four-wheel brake system is particularly effective, a neat chain compensating gear being incorporated in the cable operating mechanism.
whirled along the main roads at lightning speed, having to keep my eyes well skinned in case a man in blue hove sight. Instead of which the car was driven gently along at a comfortable touring pace, running with remarkable smoothness though some very pretty work with the gears produced something quite out of the way as regards acceleration. The bodywork gives a good position, but, as might be expected, fails to provide the luxurious comfort to be found in some of the more elaborate sports tourers, and one has to remember that the rear wheel is very close when tempted to put the elbow too far over the side. Leaving the traffic, I was treated to a turn of speed along a good wide open road, and again by using the gears with fine judgment Capt. Douglas made the little bus hum along merrily at over 85 m.p.h., with plenty
more movement left on the accelerator pedal. When going at over 70 m.p.h. he shouted to me to hold tight, and by applying the brakes brought the car to rest in an incredibly short distance, though I was expecting a skid, and said so.
” Oh ! she will skid all right, if that is what you want to see,” said my companion ; so turning off on to an unmade road I sometimes use for tests, he treated me to some very spectacular and thrilling slithers.
Coming to Succombe Hill at Warlingham we took the steep and winding ascent quite easily on second gear, and later made three fast climbs, all out on first speed, with the object of testing the cooling efficiency of the engine. Removing the radiator cap after the third ascent, there was practically no sign of overheating, such as one might have well expected. I must say the Bugatti created a most favourable impression, and at a later date I hope to be able to give some further experiences after a more extended trial, either with this or the eight cylindered model.
THE GAZOLEX WATER CARBURETTOR.
THE idea of employing water injection in internal combustion engines as a method of cooling, and to cushion the force of the explosion, is by no means new, as it has been employed on stationary gas and oil engines with considerable success in the past.
However, the high speed internal combustion engine with a large speed range and throttle controlled, as used in modern mechanically propelled vehicles, presents a much more difficult proposition to which to apply any water injection device ; and it has been left to the Gazolex Manufacturing Co., Ltd., of 50a, Kingsbury Square, Aylesbury, Bucks, to produce a practical and neat device for this purpose. One of the motor cycle models has recently been in use in one of the ” Motor Sport” machines, to wit, a high compression o.h.v. 250 c.c., which is naturally prone to knocking and harshness, unless extensive use is made of the gear box. The tank and carburettor, which is illustrated here, fitted quite neatly on the rear
chain stays, and the thin water pipe was led into the induction pipe by means of the union provided. An adjustment on the Gazolex is provided, by which the proportion of air to water fed to, the engine can be varied, in the extreme position the device being merely an extra air inlet, with the water cut off completely. Not being so much worried about petrol consumption as about power output, we used settings giving a considerable water feed with a very marked difference in the behaviour of the engine as compared with when the Gazolex was cut off by the tap provided. A slight tendency to eight stroke at very low throttle openings was noticed on turning on the tap ; but the most marked difference was the smoothness of pulling without knock or snatch, and the fact that, with the device in use, instant acceleration from low engine
. speeds on top gear was obtained with perfect smoothness. The maximum revolutions were unaffected, and the engine ran distinctly cooler. We hope at an early date to give the results of some tests on the track with regard to this latter point, and also to its effect plugs at full throttle.
To owners of sports cars and motor cycles which are harsh and prone to pinking we can heartily recommend this interesting device. The car model incorporates a dashboard control, and a feature of the instrument is the ingenious automatic piston valve, which prevents water being sucked into the combustion chamber when the throttle is closed.
All particulars and prices can be obtained from the makers.
FOR THE AMATEUR T.T.
” osEvey,” 37, Hutchinson Square, Douglas, I.O.M.., 1V1 good accommodation for Motor Cyclists ani visitors attending T.T. Practising and Race, reliable board and attention, Garage clos2 to houn id staTt, spezif0 milt-Aerate terms,