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).
Statistics for engine faults and their remedies across various models.
| Identifier | ExFiles\Box 47\3\ Scan198 | |
| Date | 30th June 1931 guessed | |
| -11- 20 HP. 25 HP. PH.I. PH.II. TOTAL. GRAND TOTAL. REMARKS. ENGINE - VALVE SPRINGS BROKEN. New type valve springs with semi open ends and circular grinding now being used and are a definite improvement, but we have had one or two recurrent failures. June Quarter. C.C. - 1 3 8 12 } 26 W.P. - - 1 13 14 } Previous " C.C. - - 1 11 12 } 31 W.P. - - 1 18 19 } Six months. - 1 6 50 57 57 ENGINE - VALVES STICKING. This can be cured by providing adequate clearance at the mouth of the valve guide to allow for the formation of carbon. June Quarter. C.C. - - 4 1 5 } 5 Previous " C.C. - - 5 3 8 } 8 Six months. - - 9 4 13 13 ENGINE OIL PRESSURE FAILS. On 20 HP. this is due to oil surging in the crankcase when braking, and is cured by fitting a baffle to the oil sump. June Quarter. C.C. 1 3 - 1 5 } 5 Previous " C.C. 1 - - 1 2 } 2 Six months. 2 3 - 2 7 7 WATER LEAKS FROM CYLINDER. Ph.I and Ph.II definitely cured by fitting nickel plated copper tubes in place of the original aluminium tubes. June Quarter. C.C. 2 - 7 2 11 } 11 Previous " C.C. 1 1 4 2 8 } 11 W.P. - 1 - 2 3 } Six months. 3 1 12 6 22 22 | ||