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 of a Lucas magneto against a standard Watford magneto for an EAC, noting dimensional differences.
| Identifier | ExFiles\Box 40\2\ Scan059 | |
| Date | 12th October 1925 | |
| X8793 To Wd.{Mr Wood/Mr Whitehead} from EFC. EFC3/T12.10.25. X.8793 - LUCAS MAGNETOS FOR EAC. Answering your Wd{Mr Wood/Mr Whitehead}1/NJ7.10.25. with attached letter from Messrs. Lucas of Oct. 6th, ref. EOT/4, having submitted the blueprint N416-A to the D.O. we have received from them the following remarks relating to the comparison of this magneto with our present standard Watford, :- 1. The thread on the driving spindle is 7/16 B.S.F. on Lucas and 3/8" Whit. on Watford. Remark. Presumably this difference would be immaterial and may even be an advantage. 2. The taper of driving spindle is 1 in 5, which works out at 11°-25' not 11°, as shown on Messrs. Lucas' drawing. Remark. We prefer to keep to our present standard taper of exactly 1 in 5. 3. The control lever should be left blank for drilling at Derby. In other respects we see no reason why this magneto should not be entirely dimensionally suitable for our tests. EFC. | ||