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).
Comparison table of specifications for various S. Motors (starter motors).
| Identifier | ExFiles\Box 68\4\ scan0200 | |
| Date | 22th November 1919 guessed | |
| -3- TABLE (S.Motors) | Machine | R-R 45a. | R-R17. | R-R24. | Lucas A510. | C.A.V. | Bosch. | Bijur. 6 volts. | R-R4B | |---|---|---|---|---|---|---|---|---| | FIELD WINDING: | | | | | | | | | | Arrgt. of coils. | Four in series. | Four in series. | Four in series. | Four in series. | To in series, to in parallel. | Four in series. | Four in parallel. | | | Resis: of field winding (cold). | .0204 | .0204 | .0204 | .00279 | .00389 | .00299 | .00125 | 3/4 | | Weight of copper composing winding (lbs.) | 3.800 | 3.800 | 3.800 | 1.750 | 2.500 | 3.200 | — | 8 3/4 | | Turns per coil. | 13 3/8 | 13 1/2 | 13 1/2 | 18 | 6 | ? | — | | | WEIGHT. | | | | | | | | | | Weight of motor complete (lbs.) | 35.5 | 35.0 | 34.5 | 21.375 | 19.25 | 39.15 | 30.5 | 33 lbs. 29 1/2 lbs. without reduction gear and sprocket. | | ||