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).
Suitability of various third-party starter motors for the Goshawk II engine.
| Identifier | ExFiles\Box 51\5\ Scan010 | |
| Date | 2nd June 1921 | |
| To Da. {Bernard Day - Chassis Design} from EFC. {E. Fowler Clarke - Electrical Engineer} c. Ry c. Da {Bernard Day - Chassis Design} /Thr. c. Ry/WER X.4342 EFC {E. Fowler Clarke - Electrical Engineer} 8/T2.6.21. 43 X.3242 - STARTER MOTORS OF OTHER MAKES FOR GOSHAWK II. During my visit to Mr. Royce we reviewed the various motors of other makes which are suggested experimentally for Goshawk II. Regarding the proposed Rotax M.T.1 L motor, he considered the external dimensions to be unsuitable, the diameter being too small, and when I informed him that there had been some difficulty as regards this motor fouling the crankcase breather, he definitely decided that this particular motor should be taken off the list and not further considered. Makers curves of performance of the C.A.V. "SC" motor of 4½" dia. were shown to Mr. Royce and it was agreed that possibly this motor was somewhat too large electrically in output. On the other hand, the Smith type 5S, 4½" dia. motor appeared to be a little too small electrically. We left it, however, that these two motors should be tried. It is suggested that we propose to Mr. Royce that as the Smith 5S motor has to be specially made in any case, it be made somewhat longer so as to give a larger output. We will do this and let you have a copy of the note. The remarks contained in our EFC {E. Fowler Clarke - Electrical Engineer} 8/T2.6.21 regarding dynamos of other makes for Goshawk II apply generally also to the case of the motors. EFC. {E. Fowler Clarke - Electrical Engineer} | ||