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).
From 'E' confirming Mr. Royce's requested alteration to the 20HP inlet cam form to raise the valve gear's bouncing speed.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan154 | |
| Date | 11th June 1929 | |
| BY.{R.W. Bailey - Chief Engineer} FROM E.{Mr Elliott - Chief Engineer} C. to SG.{Arthur F. Sidgreaves - MD} (struck through) HS.{Lord Ernest Hives - Chair} ORIGINAL (Stamp) X1770 Y5770! (Handwritten) 20HP. VALVE TIMING. Referring to your memo. BY1/G8629., 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} | ||