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).
Performance comparison of Lucas and C.A.V. motors, detailing figures for torque, speed, power, and efficiency.
| Identifier | WestWitteringFiles\H\January1922\ Scan33 | |
| Date | 3rd January 1922 | |
| Contd. -3- EFC1/T3.1.22. say, 10 or 11, the motor would be working at a higher power and higher efficiency and would appear to be better adapted for the work with this other ratio. It is possible, however, that our estimate of 66 lb-inches is on the high side, therefore a comparison with a torque of 44 lb-inches would be interesting. The figures in this case would be :- Motor speed 1310 Engine speed 156 Amperes 140 B.H.P .90 Efficiency .53 (see our EFC7/T31.10.21) Thus, compared with the C.A.V. motor, the performance at the high torque figure seemed much poorer, but on the lower torque figure, the engine speed is approximately the same though the amperes are higher and the efficiency lower. It would appear that for this motor, as wound, to be as favourably suited to the Goshawk engine as the C.A.V. the gear ratio would have to be rather higher. At a still lower torque figure the Lucas motor might show to advantage over the C.A.V., The comparison of the two performances is on the same volt-ampere characteristic of 1 volt drop per 50 amperes. The performance of the Lucas motor would not be down so much relatively to the C.A.V. on a more favourable characteristic, as the Lucas motor has a somewhat lower resistance (actually it is of considerably lower resistance in the armature, but slightly higher resistance in the field circuit). Mr. Hives states that actually on the car, the | ||