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).
Specification of performance for a magneto for the R.R. 20 HP car.
| Identifier | ExFiles\Box 57\2\ Scan230 | |
| Date | 29th March 1928 | |
| SPECIFICATION OF PERFORMANCE OF MAGNETO FOR R.R. 20 H.P. CAR. (1) The magneto shall be merely a high tension generator, i.e. no distributor is necessary but a H.T. terminal should be provided suitably placed so as to be conveniently connected to a separate distributor. The magneto shall be as compact as possible, preferably of circular or square construction, utilising short cobalt steel bar magnets, as the overall height of the magneto from its base should not exceed 5 inches. (2) The weight of the magneto complete but without coupling shall not exceed 8 lbs. (3) The length of the H.T. safety gap shall not be less than the equivalent of a sparking over voltage of 12000 steadily applied. This, in ordinary forms of safety gaps will correspond to certainly not less than 8.5 mm. and probably somewhat more. (4) The total firing range in magneto degrees shall not, if possible, be less than 50°. (5) The magneto shall be capable of complying with the performance scheduled in (5), (6) and (7) below, after first having been subjected to :- (a) A short endurance test in which the magneto shall be run for 7 hours at a speed of 2000 r.p.m. with timing lever fully advanced and sparking being caused to take place on a sequence of H.T. third point spark gaps in air set to 5.0 mm. Contd. | ||