VETERAN TYPES
VETERAN TYPES IX. A 1900 SINGLE-CYLINDER BENZ.
NO one who ever looks at the daily papers can have failed to notice some little time ago a series of photographs of a Plymouth doctor, who as a protest against paying the rates on his garage had decided to avoid payment by burying his thirty-one year old motor car—also seen in the photographs. The more discerning, too, will have recognized the automobile as an early Benz, and will have reflected that it was a pity that such an interesting relic should meet the pointless fate of interment. Actually, however, their regrets were unnecessary as the doctor apparently never progressed further with his plan than its discussion ; and the car finally passed into the sympathetic hands of Mr. C. S. Burney of Veteran Cars Ltd. When therefore during a recent visit to his premises at Brookla.nds he offered to take me for a run on the old car, I gladly accepted and decided to add a description of it to the” Veteran Types” series.
Electric ignition. An inspection of the mechanical features of the car quickly reveals that as a type the early Benz is one of the most interesting of really old motor cars. It is not in reality anything like so much the direct ancestor of the modern automobile as is say the Panhard et Lavassor of similar date, but in certain respects it is remarkably much ahead of its time, as for instance in the matter of electric ignition, which it must be remembered figured on
Benz cars some fifteen years before the appearance of the present example.
The frame of the car is made of wood, reinforced with iron and braced by crossstays to which the mechanism is attached. The engine is at the back of the car, under the main seat, and consists of a single horizontal cylinder, with its head pointing forward, the dimensions being approximately 115 x 120 mm., and the capacity therefore about 1,250 c.c. Although larger than a Modern Riley, for instance, the power developed is only about 4i h.p. which however is given off at the modest speed of 600 r.p.m. The crankshaft is also horizontal and by the first year of this century had come to be so highly regarded as to be provided with a crankcase.
A novel carburettor. On the near side of the car at the very back is an imposing looking vessel which is nothing less than the carburettor, and which is fed from the petrol tank under the seat in the centre of the car. This carburettor is warmed by the exhaust gases, and contains a float which maintains a constant level by the rather interesting method, not of lifting or letting fall a needle valve, but by resting on a pivotted plate, the other end of which prevents petrol entering when the float rises by resting on the orifice of a nozzle. The carburettor is of the surface type, and on each induction stroke of the engine air is drawn in through a gauze-covered orifice
at the top, passes:down a central pipe or chimney which ends just above the petrol level, and after licking the surface of the spirit passes out again through another vertical pipe in the form of a very rich mixture. This mixture then has to traverse a pipe some 2ft. in length, running forward to a chamber containing two valves, one of which admits the mixture and the other pure air, the relative quantities being controlled by a lever operated by the driver. The weakened mixture then has to pass a throttle, also controlled by the driver, and then, after less than another foot’s travel it at last reaches first a cleaning chamber full of discs of wire gauze and then the valve chamber of the engine.
The inlet valve is of the automatic type and is opened by the suction of the engine on the induction stroke against the pressure of a light spring. The combination of an automatic inlet valve and a throttle was found in the case of the Benz however, to introduce certain difficulties owing to thejfact that when the throttle valve was partially closed so small an amount of gas was admitted that the compression stroke began with a considerable vacuum in the cylinder. In order to obviate this, therefore, a second automatic valve is arranged in the head, with a spring nicely calculated to be a little more powerful than that of the inlet valve. It only opens, thas, when the inlet valve is incapable of filling the cylinder, and then it admits pure air.
The valve gear. Opposite the inlet valve is the exhaust valve which is operated through a rather complicated system of pivoted levers from the camshaft which is driven parallel to the crankshaft through 2 to 1 gearing. On the camshaft is a double sliding cam, one half of which is used in ordinary running, while the other half is so designed
that when brought into operation it prevents the exhaust valve from closing fully and so provides a half-compression device for starting.
An extension of the camshaft carries a vulcanite disc which has fixed on a portion of its circumference a metal piece which is electrically connected to the induction coil. Bearing against this vulcanite disc is a flexible metal arm, which Is connected to the batteries so that when it comes in contact with the metal portion of the circumference of the vulcanite disc, the circuit between them and the coil is completed. At its other end the flexible metal arm is attached to the movable end of a pivoted lever, and by rotating the pivot the position where the flexible arm bears on the vulcanite disc may be altered, and thus the point at which contact is made and the charge in the cylinder fired through the sparking plug determined. The cylinder is water cooled from two large tanks carried one on each side of the
car and a radiator slung underneath, circulation being on the thermo-syphon principle. On the opposite side to the camshaft, the crankshaft is extended to carry a pulley which drives a belt to a fast and loose pulley forward about the middle of the car. Unlike earlier Benzes this machine has only one belt and relies for its various speeds on an ordinary 3-speed gearbox. From this is driven a countershaft carrying a differential gear, and connected to the back wheels by chains. The wire wheels are fitted with carriage type solid rubber tyres and those at the back are considerably larger than those in front, suspension fore and aft being by full elliptic springs. Steering is by means of a hand lever mounted on a vertical column having at its lower end a pinion engaging with racks on the ends of two rods. The forward ends of these rods are connected to the ends of a crosshead which at the lower end of its spindle carries a V-shaped piece, each arm of which is connected through a link to one stub axle. By this method, it will be noted, each front wheel is directly steered, and the system should be free from shimmy even if balloon instead of solid tyres were fitted While we were making our inspection of the mechanical features of the Benz, Mr. Burney had set about putting the machinery in motion. First of all he turned on the petrol and watched the rod which it is attached to the float and projects through the lid of the instrument slowly rise until the correct level was reached. This Benz is very de luxe, for instead of pulling over the flywheel to start the engine, one has a starting handle under the driver’s seat, which operated through a series of shafts and finally engages with the crankshaft by means of a bevel gear. By means of this the engine was turned over a great many times on half compression, while, I suppose, mixture was pumped along those yards of induction pipe ; then the full compression cam was slid into place, the engine turned over once or twice, and a husky coughing preceded its first firing. Now it was running, and its owner was making shrewd adjustments to the controls while the engine speed rose and fell to such an incredibly low number of revolutions that
one felt that each ” turf ” must be its last. Such was not the case, however, and Mr. Burney merely called for a tin of oil, while somewhat to our modern amusement, he opened a flap door in the crankcase and inspected the big-end in action. Oil was poured in until the cup was dipping nicely, and the car was ready to take the road. The steering gear is arranged exactly in the centre of the machine, but all the other controls and consequently the driver are situated on the left. In the illustration the steering control looks rather like a wheel to which is attached a vertical handle, traction engine fashion, but actually, as we have seen, it is a horizontal lever on the top of a metal ring, one end of the lever carrying the hand grip and the other consisting of a pointer which the driver has only to set in the direction whither he would wish to go. One feels that the system would be fittingly completed by the inclusion of a compass in the centre of the steering arm
A tricky gear-change. However, by now we were seated in the car with the engine running and all ready to set off. Just below the steering lever is a horizontally disposed quadrant carrying a lever which may be placed in any of four notches, corresponding to the three forward speeds and neutral. To see the lever moved from the last named into the first speed position without any preliminary step is a little disconcerting at first, and one is relieved when the matter is explained by the driver pulling over yet another lever which shifts the belt over from the loose to the fast pulley. Meantime he had also made sundry adjustments to the throttle, ignition advance and mixture controls situated on the vertical board beneath his seat, and with the engine chugging merrily the car got under way. Second gear was engaged, the belt made fast again, and we went a bit faster, then top speed was put in and we were soon bowling merrily along at 20 m.p.h. All this time I may say the driver had been using exactly three pairs of hands, one of which was required to steer, one to operate the gear-lever, one the belt shift, and the other three the throttle, mixture and ignition controls, to say nothing of the fact that he yet
found an extra one with which to give traffic signals to the driver of a saloon car who appeared to be too amused at our equipage to steer rationally.
At 20 m.p.h. the car is remarkably comfortable and gives one to a pleasant degree the exhilaration of speed. The body is of dog-cart type, with the main seat at the back, on which we sat, of most comfortable proportions, and a little seat in front facing the other. As we bowled along I, who had thought myself free from all such heresies, could not help reflecting how much we have since sacrificed to speed. The Benz has a seat cushion stuffed with horsehair but containing no springs and solid rubber tyres, but on its flexible full-elliptic springs it ” rides ” delightfully. To-day we have to put springs or air or rubber in seatcushions and pneumatic tyres on the road wheels in order to make it possible to stay sitting in a car which has hard semi elliptic springs, bound with cord to take. the spring out of them, and in case there is any left, fitted with shock absorbers screwed up nice and tight to prevent them working !
However, to return to the Benz, another point which struck us was the great advantage of having the engine at the back. With this arrangement one gets no impression of the thumping and the clatter which is inseparable from an elderly singlecylinder motor, for apart from a pleasant ” turf-turf ” the engine is most subdued. All too soon the moment had come to return home, and the driver applied his. brakes, the hand lever operating the spoon brakes on the back tyres and the foot pedal the contracting bands on the chain sprockets. Turning round called for the use of reverse, which is engaged by pedal, and then we were away once more, headed for home. We drew up outside the works and the motor, switched off, slowly gave forth its dying chugs.
We said good-bye and climbed into our 1924 machine to return to London. “If one bought an early Benz from Mr. Burney’s stock,” so ran our thoughts as the top-gear dogs were pulled home, “one would soon learn what controlling an automobile meant.” “It would take a bit of practice,” we continued as we nosed our way through Kingston on market day..