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 comparing engine performance based on various inlet valve durations and lift profiles.
| Identifier | ExFiles\Box 13\2\ 02-page141 | |
| Date | 9th August 1931 guessed | |
| COMPARISON OF VARIOUS INLET VALVE DURATIONS RM.{William Robotham - Chief Engineer} P.23 4.78 C/R.{Sir Henry Royce} OPEN EXHAUST STD. ALUM HEAD RR TWIN CARBS 1-4" CHOKES 1-3 DIA VALVE THROAT B.H.P. R.P.M. INDUCTION DEPN lbs/sq in. M.E.P. LBS/SQ in. .013 TAPPET CLEARANCE Diagram A: SCH 1069, VALVE LIFT .490, IN (23 to 67), EX (90 to 26) Diagram B: LEG 2918, VALVE LIFT .470, IN (3 to 54), EX (58 to 12) Diagram C: SCH 1053, VALVE LIFT .430, IN (54 to 68), EX (51) INLET DURATION 272° LEG 2918 241° STANDARD 223° INLET THROAT DIA 1.9 Curve Labels: A, B, C | ||