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 6-cylinder magneto without automatic advance for the 40/50 car.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan273 | |
| Date | 25th February 1925 | |
| 25.2.25. SPECIFICATION OF PERFORMANCE OF 6-CYLINDER MAGNETO (WITHOUT AUTOMATIC ADVANCE) FOR R.R. 40/50 CAR. (1) The weight of the magneto complete but without coupling shall not exceed 13 lbs. (2) 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. (3) The total firing range in magneto degrees shall not, if possible, be less than 58°. (4) 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 teste 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 5.5 mm. (b) Immediately following (a) a short circuit test in which it is run at 1500 r.p.m. for half an hour with timing lever central and primary and secondary windings short circuited, i.e. with the low tension and central high tension distributor terminals connected to the metal framework of the magneto. (c) Immediately following (b) an open circuit test at 1500 r.p.m. for quarter of an hour with timing lever fully advanced and the H.T. terminals not connected to anything, so that the secondary discharges take place on the safety gap of the magneto. Contd. | ||