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 a 25 HP car, detailing speed improvements with different engine and axle configurations at Brooklands track.
| Identifier | Morton\M13.2\ img091 | |
| Date | 26th August 1931 | |
| 25 H.P. CAR. IMPROVED HIGH SPEED PERFORMANCE. 2. BROOKLANDS TRACK. SPEED OVER HALF MILE. 65.69 - STANDARD ENGINE AND CAR 11/50 AXLE 68.18 M.P.H. - ST'D ENGINE S.U. CARBURETTER 11/50 AXLE 75 M.P.H. (77.25) - SPECIAL ENGINE R.R. CARBURETTER 11/50 AXLE 75 M.P.H. (76.6) - SPECIAL ENGINE R.R. CARBURETTER 12/50 AXLE. 75 M.P.H. (76.92) - SPECIAL ENGINE S.U. CARBURETTER 11/50 AXLE 80.36 M.P.H. (80.36) - SPECIAL ENGINE S.U. CARBURETTER 12/50 AXLE. 67.16 M.P.H. (70) - JAPAN I (16 G IV) 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. | ||