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).
Test report comparing the performance of Graphite Bronze, Sintered Bronze, and Ferodo clutch facings.
| Identifier | ExFiles\Box 103\1\ scan0266 | |
| Date | 1st December 1938 | |
| 512 COPY FOR FILES. 1.12.38. GRAPHITE BRONZE FACINGS. 17.G.IV. Following report dated 17.10.38, I again tested car and found clutch entirely satisfactory. The Cleveland Graphite Bronze were fitted 29.9.37 and had covered 9,505 miles. On removal, both facings and also face of driven plate were smooth, glazed, free from rings or score marks, and wear not measureable. The springs had lost in poundage, the total thrust being 1041 lbs. or 7.7% down, but the take up was normal, and only moderate slip on engaging against racing engine. Working μ = .194, but recommend .18 to .19 forregular use. On 20.11.38, segments of Sintered bronze were fitted to Rm.{William Robotham - Chief Engineer}554, the old springs first being tried giving a thrust of 945 lbs., μ = .215. Excessive slip on full throttle engagement but O.K. when once engaged. 1.12.38 fitted .100 Ferodo discs under same springs, making thrust 1055 lbs. μ = .19 now O.K. and can put into service. Speedo reading 62,696. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} | ||