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).
Calculations for starter motor to engine transmission torque losses and ratios.
| Identifier | ExFiles\Box 50\2\ Scan092 | |
| Date | 9th June 1921 | |
| X4298- 9.6.21. X.3082 - STARTER MOTOR TO ENGINE TRANSMISSION. Assumed losses (starting with 100% torque on motor). 6 : 1 reduction on motor, 3% loss giving 6 x 97% torque on motor chain wheel. 14 : 13 chain drive, 3% loss giving 14/13 x 6 x 94% torque on gear box chain wheel. 6 : 1 reduction on gear box, 3% loss giving 14/13 x 36 x 91% torque on dog clutch. 3 : 5 step up in gear box and remainder of transmission, 4% loss giving 3/5 x 14/13 x 36 x 87% torque on engine i.e. 2020% torque on engine. Effective torque ratio 2020/100 = 20.2 Speed ratio 23.3 EFC. | ||