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 chart comparing lap speeds for a 25 HP car with various modifications at Brooklands Track.
| Identifier | ExFiles\Box 181\M13\M13.2\ img090 | |
| Date | 26th August 1931 | |
| 26 8 31 25 HP CAR. IMPROVED HIGH SPEED PERFORMANCE. 1. BROOKLANDS TRACK. LAP SPEED. 65.87 M.P.H STANDARD ENGINE AND CAR. 11/50 AXLE. 67.57 M.P.H STANDARD ENGINE. S.U. CARBURETTER. 11/50 AXLE. 72.49 M.P.H (73.45) SPECIAL ENGINE. R.R. CARBURETTER. 11/50 AXLE. 73.6 M.P.H (73.6) SPECIAL ENGINE. R.R. CARBURETTER. 12/50 AXLE. 75.23 M.P.H (76.62) SPECIAL ENGINE. S.U. CARBURETTER. 11/50 AXLE. 76.39 M.P.H (78.43) SPECIAL ENGINE. S.U. CARBURETTER. 12/50 AXLE. 65.52 M.P.H (70) JAPAN I (16GIV) SPECIAL ENGINE SIGNIFIES:- MODIFIED VALVE TIMING, VALVE LIFT, COMPRESSION RATIO AND EXHAUST SYSTEM (THE FIGURES IN BRACKETS REPRESENT CUT OUT OPEN SPEEDS, THE INCREASE IN SPEED BEING INDICATED BY THE FULLY SHADED AREA) A.J. LIDSEY. | ||