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).
Table comparing chassis starter rolling condition figures for various motor models.
| Identifier | ExFiles\Box 34\3\ Scan168 | |
| Date | 11th May 1927 | |
| X2642 CHASSIS STARTER ROLLING CONDITION FIGURES. X3082 X503 MOTOR. | 45a. | 45a.sp.{Mr Spinney} | 45b.expl. | 45b.prodn. | 45b.sp.{Mr Spinney} | 45b.vi.a. | 45b. V.i.a. Series par^l ---|---|---|---|---|---|---|--- ENGINE TORQUE. | 1155 | 1155 | 1155 | 1155 | 1155 | 1155 | 1155 GEAR RATIO. | 23.3 | 23.3 | 23.3 | 23.3 | 23.3 | 23.3 | 23.3 MOTOR TORQUE. | 55 | 55 | 55 | 55 | 55 | 55 | 55 MOTOR SPEED. | 940 | 1430 | 1030 | 980 | 1280 | 1075 | 1195 AMPERES. | 117 | 133 | 111 | 120 | 151 | 107 | 145 VOLTS. | 10.0 | 9.9 | 9.7 | 9.5 | 9.0 | 9.90 | 9.10 ENGINE SPEED. | 40 | 61 | 44 | 42 | 55 | 46 | 51 E.H.P. | 1.57 | 1.77 | 1.44 | 1.53 | 1.92 | 1.45 | 1.76 B.H.P. | .82 | 1.25 | .90 | .855 | 1.12 | .94 | 1.03 EFFICIENCY. | .52 | .705 | .625 | .56 | .61 | .65 | .59 11.5.27. EFC. | ||