Confirming Mr. Royce's requested change to the 20 HP inlet cam form (Sch. 1153) to improve valve gear performance.
| Identifier | ExFiles\Box 33\4\ Scan134 | |
| Date | 11th June 1929 | |
| BY. {R.W. Bailey - Chief Engineer} from E. {Mr Elliott - Chief Engineer} X1770 E3/M11.6.29. c. to Sg. {Arthur F. Sidgreaves - MD} Hs. {Lord Ernest Hives - Chair} 20 HP. VALVE TIMING. X1770 X5770 (crossed out) Referring to your memo. Byl/G8.6.29, and telephone conversation of today's date, kindly note this confirms that Mr.Royce wishes the period of the heavy acceleration A3 of the inlet cam form - Sch. 1153 - reduced from 7 to 6 divisions. The object of this alteration is to reduce the value of the decelerations A.4.a., and A.4.b., thus raising the bouncing speed of the valve gear. The proposed cam forms are otherwise approved. E. {Mr Elliott - Chief Engineer} | ||
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).