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 curves (BHP and MEP) for a Phantom II engine with three different camshaft specifications.
| Identifier | Morton\M19\ img284 | |
| Date | 20th July 1931 guessed | |
| P.II. POWER CURVES (ALL TAKEN OPEN EXHAUST) A R.TYPE 110° SHAFT. TWIN CARBS 1.300 DIA CHOKES. STD. COMP. RATIO B. W.W. " 120° SHAFT. " C STD. 116° SHAFT. " V1182 B.H.P. 170 150 130 110 90 70 50 MEP lbs/sq in | ||