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).
Clutch slip tests performed on Porlock Hill using a Borg & Beck clutch.
| Identifier | ExFiles\Box 129\2\ scan0100 | |
| Date | 11th November 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X1110 Hs{Lord Ernest Hives - Chair}/Smth.14/KW.11.11.35. Borg & Beck Clutch - Tests on Porlock Hill. 1-B-IV was taken down to Porlock for clutch slip tests. The car was fitted with a 10" Borg & Beck clutch (SK.30604/2) lined with F.F.1 material and 147/155 lb. springs to arrangement Ex.18198. The car was weighted to 1 ton 17 cwts. 2 1/4 qrs. excluding the two drivers. On the first ascent of the hill some 30 starts were made and the clutch never failed to take up the drive. During this ascent, however, no attempt was made to start on the very steep bit on the inside of the second corner. After allowing the clutch to cool off for 1/4 hour a second ascent was made. 20 successful starts were made before the second corner was reached, but the clutch would not drive on the steep bit. During subsequent ascents the clutch always slipped on the second corner and very frequently during the first start also. The climbs were started on the steep straight portion just after the first corner. The clutch was allowed about 1/4 hour between each climb to cool off. During 112 starts the wear on the linings was .009" (1/16" of pedal movement). Hs{Lord Ernest Hives - Chair}/Smth. | ||