Performance comparison chart of a 25 HP car's lap speeds at Brooklands Track with various engine and axle configurations.
| Identifier | ExFiles\Box 5a\1\ 01-page207 | |
| Date | 26th August 1931 | |
| 25 HP CAR. IMPROVED HIGH SPEED PERFORMANCE. BROOKLANDS TRACK. LAP SPEED 65.87 MPH STANDARD ENGINE AND CAR. 11/50 AXLE 67.87 MPH STANDARD ENGINE S.U. CARBURETTER. 11/50 AXLE 72.48 MPH (73.45) SPECIAL ENGINE R.R. CARBURETTER 11/50 AXLE 73.6 MPH (73.6) SPECIAL ENGINE R.R. CARBURETTER 12/50 AXLE 75.23 MPH (76.62) SPECIAL ENGINE S.U. CARBURETTER 11/50 AXLE 76.39 MPH (78.43) SPECIAL ENGINE S.U. CARBURETTER 12/50 AXLE 65.52 MPH (70) JAPAN(Experimental Engine) I (16GII) 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) | ||
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).