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 from 'The Motor Trader' presenting comparative chassis efficiency data from a report by Dr. Riedler.
| Identifier | ExFiles\Box 74\4\ scan0151 | |
| Date | 20th August 1910 | |
| Handwritten text: The Motor Trader. August 20th 1910 13489 464 Printed text: Comparative Chassis Efficiency Data. A volume of some nine reports, comprising 330 pages and 227 illustrations, has been issued from the Laboratory for Motor Cars at the Charlottenburg University. The work has been compiled by Dr. Riedler, and an English edition is available for one guinea. The data were obtained from chassis braking tests, taken through friction braked rollers and dynamos, similar apparatus being now fairly common in British motor works. The report deals with data from a 30 h.p. Renault car of 1905, a 35 h.p. Bussing lorry, a 40 h.p. Coventry Daimler-Knight car, a 70 h.p. Adler car, a 100 h.p. Benz car, and a Mercedes electromobile. Comparative data are given also from tests of a Mercedes-Knight engine and poppet valve system. The results of the trials are summarized at the end of the work. Though the Renault car was of a much earlier date than the others, its results seem more striking in its case than some of the others. Its four cylinders had a bore and stroke of 4in. by 5 1/8in. with a compression ratio of 4.02, and valves of 1 15/16in. diameter with 3/8in. lift. The transmission was by a three speeds and reverse gear and a bevel geared axle with 34.4492in. by 4.1330in. (875 mm. by 105 mm.) tyres. At a speed equivalent to a road rate of 37 1/2 miles an hour, the engine's revs. being 950 revs., the following data representing percentages of power absorbed or otherwise not available for propulsion resulted:—Exhaust piping and silencer, 9.7:—Transmission gear, 12.7:—Friction and air-resistance of front wheels, 2.6:—Front tyres, 4.8:—Back tyres, 16.2:—Air resistance of vehicle, 31.0. At a road rate of 32 miles an hour the transmission loss on the direct drive, i.e., from engine to road wheels, averaged 12.7 per cent. for the Renault, 12.8 for the Adler, the engine of which runs 50 revs. faster than the Renault at the corresponding road speed mentioned, and 11 per cent. for the Coventry Daimler. It should be noted in this connexion that the Renault weighed 31 cwts., against the Adler's 21 cwts., and 28 cwts. for the Daimler. The efficiency of the Lanchester-Daimler transmission and worm axle gearing is stated to range from 84 to 90 per cent. on the direct drive. | ||