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 curves (BHP and BMEP vs RPM) for three different inlet valve timing configurations.
| Identifier | ExFiles\Box 182\M19\ img240 | |
| Date | 5th August 1931 guessed | |
| COMPARISON OF VARIOUS INLET VALVE DURATIONS RM{William Robotham - Chief Engineer} P23 4.78 C/R OPEN EXHAUST STD ALUM HEAD R.R. TWIN CARBS 1-4" CHOKES 1-5" DIA VALVE THROAT .013 TAPPET CLEARANCE Diagram A: SCH 1063 VALVE LIFT .490 EX IN Timings: 26, 73, 67 Diagram B: LEC 2918 VALVE LIFT .470 EX IN Timings: 23, 12, 58, 54 Diagram C: SCH 1093 VALVE LIFT .430 EX IN Timings: 66, 33, 54 Left Y-Axis: B.H.P. (90-170) Right Y-Axis: B.M.E.P. LBS/SQ.INS, INDUCTION DEPN (60-110) X-Axis: R.P.M. (500-3500) INLET THROAT DIA 1.9 INLET DURATION 272° LEC 2918 241° STANDARD 223° | ||