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).
Issues with tappet noise, gearbox difficulty, and clutch performance.
| Identifier | ExFiles\Box 21\7\ Scan027 | |
| Date | 12th June 1925 | |
| R.R. 493a (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF HS{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}/LG.231025 but on opening the bonnet two bad tappet knocks were noted, the valve gear being generally less silent than that of a R-R.{Sir Henry Royce} The front end drive was not particularly noisy. The overhead rocker shaft is not in continuous connection with the oil pump, but is cut off by a three-way valve which is operated by a foot control on the dash. Only when this control is depressed is the rocker shaft lubricated. The makers recommend that lubrication should be carried out two or three times in a day's run, the plunger being depressed for a few moments each time. This does not lubricate the valves, which, the driver stated require periodical attention with an oil can. Ignition advance - semi-automatic. GEARBOX. The most objectionable feature of this item was the difficulty of moving the gear lever out of top gear when changing down. It is apparently maintained in its position by very strong springs. Its location with regard to the driver is also such that it is not easy to control. Indirect gears are fair - they are not so quiet as the average Phantom; reverse on this car was definitely a bad gear. CLUTCH. Multiple plate - dry disc Ferodo and steel surfaces. This clutch gave a very smooth engagement and stopped very reasonably quickly. There was no sign of juddering even when re-starting on a considerable gradient. The pedal pressure required to free the clutch was not excessive. | ||