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).
Performance comparison chart for the Phantom III engine under various configurations.
| Identifier | ExFiles\Box 96\2\ scan0239 | |
| Date | 2nd June 1937 guessed | |
| PHANTOM III POWER COMPARISON TESTS RUN OPEN EXHAUST AND WITH STD. STROMBERG CARB. CURVE ①: STD. PROD. 6 PORT ENGINE TIMING WITH .020 CLCE I.O. 7° PTDC E.O. 47° BBDC I.C. 42° PBDC E.C. 8° BTDC CURVE ②: 4 PORT HEAD OTHERWISE AS CURVE ① CURVE ③ Nº 1.: 4 PORT HEAD WITH SOLID ROCKERS CLCE. SET AT .012 LEC. 5401 CAMSHAFT TIMING .030 CLCE I.O. 5° PTDC. E.O. 38° BBDC I.C. 30° PBDC. E.C. 85° BTDC. CURVE ④: CONTINENTAL PRACTISE. UNIT Nº 8 4 PORT HEADS DETURBULATED 6.5:1 C.R RM{William Robotham - Chief Engineer} 38 x 44 CAMS WITH NORMAL TAPPET SETTINGS .006 AND .008 TIMING .020 CLCE I.O. 1° BTDC E.O. 40° BBDC I.C. 48° PBDC E.C. 6° BTDC AXIS LABELS: LEFT Y-AXIS: B.H.P RIGHT Y-AXIS: M.E.P. LBS/SQ" X-AXIS: R.P.M. GRAPH LABELS: MEP (LBS/SQ") B.H.P SIGNATURE: Sudds | ||