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).
Tests on a starter motor for a car with a 3-speed gear box.
| Identifier | ExFiles\Box 75\1\ scan0154 | |
| Date | 11th August 1920 guessed | |
| TESTS ON STARTER MOTOR FOR CAR WITH 3-SPEED GEAR BOX. Conditions - Engine cold - car having been left all night. Temperature of motor carcase 13°C. Voltage of battery 12.4. Resistance in switch .201 Ohms. Test No. | Voltage at motor. | Amps. | Revs. of motor. 1 | 1.6 | 40.0 | 180 2 | 1.6 | 39.8 | 200 3 | 1.6 | 39.8 | 190 4 | 1.6 | 40.0 | 200 Conditions - Engine and motor warm, several starts had been made. Temperature of motor carcase 21°C. Voltage of battery 12.9. Resistance in switch .201 Ohms. Test No. | Voltage at motor. | Amps. | Revs. of motor. 1 | 2.0 | 38.5 | 430 2 | 2.0 | 38.5 | 400 3 | 2.0 | 38.3 | 410 Conditions - Engine and motor hot - car had been run for a considerable time. Temperature of motor carcase 40°C. Voltage of battery 12.7. Resistance in switch .201 Ohms. Test No. | Voltage at motor. | Amps. | Revs. of motor. 1 | 4.5 | 29.6 | 1650 2 | 4.2 | 31.2 | 1470 3 | 3.8 | 31.8 | 1270 CONTD:- | ||