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).
Representative performance quantities for an EAC.II starter motor.
| Identifier | ExFiles\Box 64\1\ scan0194 | |
| Date | 7th November 1924 | |
| X 7620. EFC2/T7.11.24. X.8620. EAC.II. STARTER MOTOR. Representative performance quantities on the basis of overload engine torque of 1900 lb-inches. Actual figures Speed reduction ratio = 30. 28.9. Engine speed assumed = 30 r.p.m. 22 Motor speed = 900 r.p.m. 635 With 85% gearing efficiency, the effective torque ratio = 25.5 24.6 Motor speed = 900 Motor torque = 74.5 lb-inches. 77.3 Brake power of motor = 1.063 H.P. .78 With 53% electrical efficiency, electrical H.P. .405 supplied = 2.008, 1.923 corresponding to 1500 watts (nearly) 1430 or to Volts 8.44 8.72 Amperes 178 164 EFC. | ||