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).
Standardization of dynamo and starter motor carcase dimensions for different car models.
| Identifier | ExFiles\Box 61b\3\ scan0093 | |
| Date | 23th February 1921 | |
| R.R. 235A (100 T) (S.H. 798 10-12-20) G 2947 To CJ. from R.{Sir Henry Royce} c. to EFC. xoz s6027 R4/G23.2.21. X.3533 X.294. X.3534 X.3526. RE ELECTRICAL EQUIPMENT. X.543. With reference to the electrical programme, we are arranging for the engine we are designing to be fitted with a 5½" carcase for the dynamo. We have thought that such a carcase dimensions might be made standard, so as to give us an easy and straight forward programme, in which case we should alter the length of the machine for the various requirements of motor and generator, large and small machines :- This may not, however, prove entirely satisfactory when we come to get out the exact dimensions, and it may be necessary for us to have three diameters of carcase, namely - Starter motor for the small cars -------- 4½" dia. Dynamo for the small cars -------------- 5½" dia. Starter motor for the large cars -------- 5½" dia. Dynamo for the large cars. ------------- 6½" dia. I should be glad if Mr. Clark would consider these figures, and let me know what are the figures of the various makers. It will be noticed that the starter motor for the "Goshawk II" will have to be capable of starting an engine of approximately 3,000 c.c. and that for the new 40/50 H.P. capable of starting an engine of approximately 6,000 c.c. R.{Sir Henry Royce} | ||