From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Article discussing the Brewer hot-spot carburetion design and the introduction of American-made Kenyon cord tyres to the UK market.
| Identifier | ExFiles\Box 50\3\ Scan013 | |
| Date | 22th December 1920 | |
| The Motor 1070 December 22, 1920. HOT-SPOT DESIGN.—Contd. induction chamber which is heated to a high temperature by the exhaust gases and on which the liquid or unvaporized particles of the fuel impinge as they travel up the pipe. As in every other component of the car, there are right and wrong designs of hot-spots, but one which claims to be an improvement on all existing types has lately been produced by Mr. R. {Sir Henry Royce} W. A. {Mr Adams} Brewer, whose well-known book on carburation will be familiar to many of our readers. This gentleman has also recently returned to this country after six years' absence in America, where he has been studying the carburation problem for some six years. by reason of their inertia and momentum, the globules of liquid cannot pass down the induction pipe until they have become vaporized into a gaseous form. The action is analogous to the following:— Against a sheet of red-hot steel or iron throw a cupful of water. Drops of water will fall away and comparatively only a small proportion will be turned into steam. Now sluice the same amount of water slantwise at the same plate so that the liquid more or less slides over the surface and practically every drop will be turned into steam. With the Brewer system the globules of unvaporized fuel are sluiced against the sides of the hot-spot and thus absolutely complete vaporization is assured. Conserving a Dry Mixture. It will be seen that in the Brewer design of hot-spot the gas from the carburetter is led up a pipe which is connected tangentially to a circular chamber. This chamber is jacketed with exhaust gases, the lead to the inlet ports branching off at right angles to the entrance pipe. It will thus be seen that this differs considerably from the usual “T”-shaped hot-spot in which the globules of unvaporized fuel coming from the carburetter merely impinge “head on” to a flat hot-spot and, as it has been proved, rebound in a still unvaporized condition and are then taken along with the mixture to the cylinders or else deposit themselves in the induction pipe. The average motorist has no idea how much loose fuel actually collects in the induction pipe when the car is running, and would be surprised to learn exactly what an important part this plays in producing bad carburation. With the Brewer system the gas is whirled in a vortex round the circular chamber and, Preventing Deposition of Fuel. Other faults in carburation are corrected by this system. For instance, at low engine speeds, when the throttle is opened, a certain amount of liquid straggles out of the jet, but has not sufficient velocity to carry it up the vertical induction pipe, and, therefore, it normally tends to fall back into the carburetter, producing momentarily uneven running. In the Brewer hot-spot there is a cone incorporated which catches this loose fuel and retains it in an annular puddle pocket until such time as it is properly heated up and in a vaporized state is carried along with the rest of the mixture. Similarly, puddle pockets are formed in the induction pipe itself, preventing loose fuel from getting into the cylinders. These Brewer manifolds are made in all forms and can be adapted by all manufacturers whose engines have their inlet and exhaust pipes on the same side of the engine. A NEW CORD TYRE. An American Production of Considerable Repute to be Sold in this Country. CORD tyres offer in the main two very great advantages. They can be run sufficiently soft to enable them to function properly as cushioning devices without any disintegration taking place or friction being produced in their walls. In other words, they are far more flexible than fabric types; this has been proved by very convincing tests. Moreover, they possess a degree of resiliency which not only renders riding in a car fitted with cord tyres more comfortable, but also considerably lengthens the life of the car itself. As might be expected, therefore, new makes of cord tyres are continually being put on the English market. One of the latest to arrive is the Kenyon, an American tyre, manufactured by the Kenyon Manufacturing Co. (Inc.), of Brooklyn, New York. This concern has had 60 years' experience in producing all types of rubber. The size of their factory is not imposing, and mass production methods are not used, with the result that a greater degree of care in the construction of each individual tyre is assured. Turning to the illustration, which, incidentally, is an untouched photograph of an actual tyre taken in a strong light, shows that the rubber used on the walls is of an entirely different composition from that employed to form the tread. This is a very satisfactory point. Walls should be flexible, while the tread must be tough. The rubber used is of the finest quality, and we can assure our readers that an inspection of a Kenyon cover is sufficient to prove that it is an extraordinarily sound proposition. Its price, moreover, is very attractive. Cord tyres are usually expensive, but by scientific methods of production the Kenyon cord tyres are sold in this country at the same price as rubber studded fabric tyres, and they thus offer the advantages of more comfortable running and longer mileage without any higher first cost. The standard tread, as can be seen from the illustration, is calculated to form an efficient non-skid device. In the Kenyon the tread is made of very tough though fairly flexible rubber, extremely hard to pierce and capable of standing all normal use. Incidentally, it should be mentioned that all Kenyon covers are oversize. These tyres are being handled in this country by a branch of the Kenyon Co., at 21, St. {Capt. P. R. Strong} James's Street, W. Captain W. Bowen, who was long associated with G.W.K. cars, holds a prominent position in the concern. The new Kenyon cord tyre, which sells at a very attractive figure and is particularly well made. | ||