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).
Graph showing the effect of various inlet valve timings on brake horse power against RPM for engine 1G1.
| Identifier | ExFiles\Box 48\4\ Scan102 | |
| Date | 20th December 1923 guessed | |
| EFFECT OF VALVE TIMING ON POWER ENGINE 1.G.1. EXHAUST VALVE TIMING FIXED. INLET TIMING VARIED. BRAKE HORSE POWER R.P.M EXHAUST TIMING (CONSTANT) E.C. 40° E.O. TAPPET CLEARANCE - .010 INLET: I.C. 5° I.O. 23° I.C. 20° I.O. 20° I.C. 4° I.O. 42° I.C. 8 1/2° I.O. 22° | ||