A Visit to an Experimental Engineering Works.
SOME ACTIVITIES AT THE LABORATORY of RESEARCH ENGINEERS, Ltd.
IT is well known that whilst some manufacturers
take a keen interest in the sporting side of motoring, others are content to turn out sports models which consist of little more than standard chassis with special bodies and a great amount of interest is shown by amateurs with an engineering turn of mind in securing abnormal performance from cars of the latter variety.
There is, however, a point beyond which the amateur cannot go owing to the limitations of his equipment, and this is where the services of the specialist come in. Readers are already familiar with the activities of some of the larger firms in this line of business, but we recently had the opportunity of visiting the interesting works of Research Engineers, Ltd., and also of examining some samples of the work turned out from their shops.
Tuning Up Sports Engines.
At the time of our visit a sports engine had just arrived at the works and the works engineer explained the procedure adopted in such cases which is briefly as follows : The engine is mounted on the test bed shown in Fig. 1, to ascertain its performance in order that accurate data can be obtained by means of power and consumption curves. The apparatus shown comprises a Heenan and Fronde hydraulic dynamometer, capable of absorbing 225 b.h.p. at 6,000 r.p.m., the actual readings being obtained by varying the brake load by means of sluice gates incorporated in the water dynamometer, which is recorded on a spring balance. The sluice gates are regulated by the large hand wheel shown in the illustration.
Situated above the brake is a Brown and Barlow flowmeter, which records the actual amount of fuel consumed by the engine in pints per hour. This apparatus, together with a revolution counter, driven from the dynamometer main shaft gives very accurate measurements of power, fuel consumption and engine speed serving as a basis for subsequent comparisons. Having thus determined the characteristics of an engine, the drawing office now takes a hand in the proceedings and furnishes detailed drawings for any component parts which appear to need modification. For example, in certain cases, owners are prepared to invest in an entirely new camshaft which may be made
on the premises by a profile grinding machine. Special attention is paid to the lightening of reciprocating parts and by a careful study of the design metal can be removed without seriously affecting the factors of safety.
Research Engineers, Ltd., have made a careful study of the problems of supercharging and have already fitted super-sports cars with supercharging apparatus to the design of their clients. In one case an 11.9 h.p. engine developed 65 b.h.p. without supercharging as shown on the dynamometer, and after tuning and the addition of the supercharge the power output increased to Ioo h.p., which was maintained regularly during several long bench tests. In the experience of this firm the effect of over-supercharging is not desirable, for in several instances it has been found that the design of a normal engine is not adequate to resist the enormous stresses imposed by forced induction.
Increased Power Output.
As an example of increased power output obtained by scientific means we may mention the case of a 498 c.c. motor-cycle engine which, when first tested, produced zo h.p. at 4,400 r.p.m. and after super-tuning and various mechanical modifications the power was increased to the astonishing figure of 27 h.p. at 5,000 r.p.m.—an extremely good performance for a power unit rated at 3i h.p.
Some Examples of Engineering Research.
In addition to undertaking tuning and testing operations of a normal character, the work of this establishment
includes manufacturing numerous intricate machines and apparatus designed by inventors, a few of which are to be seen in the accompanying illustrations. Fig. 2 represents a novel attempt to produce an engine with a low weightpower ratio and consists in a double acting cylinder with a stationary trunk piston and reciprocating cylinders. The latter are mounted on longitudinal slipper guides, and have two trunnions forming the gudgeon pins for the external connecting rods. Though no details of the actual performance of this engine were recorded, it serves as a typical example of the accuracy of machining methods used in its construction.
Fig. 3 represents the crankshaft assembly used in a two-stroke twin cylinder aeroplane engine which competed successfully in the light aeroplane trials of 1923. The whole engine was built to the design of the inventor by Research Engineers, Ltd., and gave a very creditable power output on its bench test for prolonged periods.
Variety in Engineering Achievements.
Catering as they do for the inventor the works are often called upon to execute some remarkable jobs. Prior to the opening of the British Empire Exhibition, one of the intending exhibitors brought some stuffed birds to the works with a request that they should be fitted with mechanical singing apparatus. Nothing daunted, the job was undertaken by the technical
staff, and, when the result was exhibited at Wembley, the Queen commented on the naturalness • of the song of the birds, and, though several clients have submitted perpetual motion machines for construction, the serious business of developing motor engines on high efficiency lines continues to occupy the resources of this progressive little firm.