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).
Magneto performance and timing, noting it fails the low speed sparking specification.
| Identifier | ExFiles\Box 65\3\ scan0429 | |
| Date | 15th January 1931 guessed | |
| WE 72 contd. (2) virtually fully advanced. The figures obtained were as follows:- magneto run in normal direction. advance 110 r.p.m. central 165 " retard 270 " magneto run in reversed direction. advance (retard normally) 85 r.p.m. central 220 r.p.m. retard (advance normally) 400 r.p.m. Incidentally this magneto does not pass our production specification of low speed sparking by a considerable margin, retarded. Upon investigating the internal timing of the magneto together with the distributor we arrived at the following figures :- (a) Armature and contact breaker timing make Breaks advance. 5.5° 110° retard. 66.5° 171° Range 61° Period 104.5° Make Ratio = .58 | ||