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).
Test results and specification adjustments for the Bentley starter motor.
| Identifier | ExFiles\Box 62\1\ scan0227 | |
| Date | 16th December 1933 | |
| WST Hs{Lord Ernest Hives - Chair}/Wst. 86134 BY/RD1/W.16.12.33. Bentley Starter Motor Specification. After testing the first 26 starter motors we find the average to work out as follows :- 39.6 lbs." The lowest was 37.2 lbs." at 1680 revs. — .992 BHP The highest was 41.4 lbs." at 1450 revs. — .952 We suggest, therefore, that you now adjust the specification to meet production conditions. \ 1.03 BHP It is quite remarkable that the first three motors tested by the Experimental Department gave such outstanding performances, whereas the first few motors tested on production gave such poor performances. There has, however, been steady improvement until it would appear that there will be no difficulty in working within the limits stated above. May we remind you that a fresh specification will be required for the 20/25 H.P., for "D2" Series, at which time we are introducing the Bentley type starter motor on the 20/25 H.P. chassis, but with 8.4 : 1 gear ratio. BY/RD. | ||