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 four Phantom II engine power curves taken with an open exhaust.
| Identifier | ExFiles\Box 13\2\ 02-page084 | |
| Date | 3rd June 1931 | |
| CURVES(3) P II POWER CURVES, ALL TAKEN WITH OPEN EXHAUST (A) RR CH. EAGLE IX CARB (4.9:1 COMP RATIO) (R TYPE 110° CAMSHAFT) (B) TWIN CARBS 1.4 CHOKES ( " " ) ( " " ) (C) " " 1.3 " (STD COMP RATIO) (STD P II CAMSHAFT) (D) STD CARB. ( " " ) ( " " ) B.H.P. R.P.M. A B C D R.W.S. 3-6-31 | ||