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).
Low-speed sparking characteristics, comparing different magnetos and drive mechanisms.
| Identifier | WestWitteringFiles\I\July1922\ Scan129 | |
| Date | 31th July 1922 | |
| Contd. -11- EFC1/T31.7.22. (16) Low Speed Sparking Characteristics (See p.2 re chain drive on this test). Speeds at which regular sparking occurred on 5.5 mm. gaps with (a) Fully advanced position) Corresponding (b) Central position ) to selected (c) Fully retarded position) range. were found to be:- SPEED Magneto. Advanced. Central. Retarded. ZR.6 56 105 150 EO6c 210 200 200 ELO.6 67 68 69 N.B. A comparison of the low sparking speeds with belt and chain drives had been made on the ZR.6 magneto previous to the endurance test and had given the following results :- SPEED Drive. Advanced. Central. Retarded Belt. 85 140 200 Chain. 68 128 175 These figures are given to show the extent of the error introduced by driving the magneto with belt, as was done in the case of previously reported tests. The lowest sparking speed of the ELO6 is the lowest recorded speed for a magneto in the retarded position. A comparison of the figures of this machine with those of the ZR.6 shows up decidedly in favour of the sleeve type magneto. The weight is of course somewhat greater - 17.7 lbs. as against 15.4. The results obtained for the Contd. | ||