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 of Phantom II power curves with an open exhaust, comparing two different camshaft configurations.
| Identifier | ExFiles\Box 92\2\ scan0120 | |
| Date | 3rd June 1931 | |
| CURVE I PH. II POWER CURVES OPEN EXHAUST 4:6 COMP. RATIO A.{Mr Adams} TWIN CARB. 1.30" CHOKES (STD COMP. RATIO)(R TYPE 110° CAMSHAFT) B. " " " " ( " " " )(STD CAMSHAFT) B H P R P M A B R.L.S. 3-6-31 | ||