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).
Over-oiling tests, gearbox noise, and clutch performance.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan312 | |
| Date | 31th December 1925 | |
| R.R. 493A (50 H) (D.D. 81, 12-6-25) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF Hs{Lord Ernest Hives - Chair}/HS{Lord Ernest Hives - Chair}/LG31.12.25 'tinny' in proximity to manifold. Detonations scarcely audible at any speed or throttle opening. OVER-OILING. We carried out careful tests to ascertain if this engine shewed any signs of oiling up plugs. The engine was run light for ten minutes and then suddenly accelerated; the quantity of smoke expelled from the exhaust was no worse than that of a 20 HP. under similar conditions. The test was repeated, and the plugs inspected at the conclusion of the idling period; they were perfectly dry. The gear oil pump emitted a definite howl when the engine was accelerated in neutral. The difficulty of providing a quiet gear pump under load has apparently given the Daimler people a certain amount of trouble. GEARBOX. This is a four speed central change. The plunger springs maintaining the lever in position were too strong, making the change objectionable; this box is apparently somewhat worse than standard in this respect. The indirect gears were very noisy, roughly 100% more noisy than the 20 HP. four-speed box. Side shaft very fair. CLUTCH. Single plate dry clutch. This is a very good clutch. A standing start was made in top gear on a slightly up-hill gradient without any signs of shuddering. The clutch could be made to shudder with trick driving however. It struck one as contd :- | ||