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 power output (BHP) and Mean Effective Pressure (MEP) against RPM for a Phantom II engine with different camshaft and rocker setups.
| Identifier | ExFiles\Box 125\1\ scan0094 | |
| Date | 14th June 1934 | |
| POWER COMPARISONS (PHANTOM II) OPEN EXHAUST 5.95:1 C.R. F28248 CAMSHAFT .440 VALVE LIFT STANDARD ROCKERS. STD SEMI-EXPANDING PISTON STD INTAKE SILENCER TIMING O/L 10°E I/C 50°L E/O 54°E E/C 8°L NO SPARK C AT 3500 F30070 CAMSHAFT .420 VALVE LIFT CADILLAC TYPE ROCKERS. LARGE SEMI-EXPANDING PISTON NO INTAKE SILENCER TIMING O/L 5°E I/C 5° ROC. IN SAT. BDC E/O 46°E E/C 14°E VALVES SEATING BADLY POWER CURVE NOT SETTLED BHP INDUCD DEPN. MEP lbs/sq RPM C.W.R. 14-6-34 | ||