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).
Test report on sparking characteristics, electrical resistance, and noise levels of an ignition component, compared to the Z.R.6 model.
| Identifier | WestWitteringFiles\F\May1921\ Scan43 | |
| Date | 4th May 1921 | |
| R.R. 235A (100 T) (S.H. 798, 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 3947 Contd. -4- EFC4/T4.5.21. (15) High Speed Sparking Characteristics. Regular sparking took place at all high speeds up to 3500 on 7.2 mm. gaps, for all positions of the timing lever (on our range). With lever advanced, shorting any one gap extinguished the spark following at all high speeds (over 1500 r.p.m.), but effect was not so decided at central position and still less at retard. Sparks otherwise appeared equal. Generally speaking this is a better performance than that of the Z.R.6. (16) Low Speed Sparking Characteristics. The lowest speeds for regular firing on 5.5 mm. gaps in air for advance, central and retard were 102, 124 and 180 r.p.m. respectively. It will be noticed that although the slowest speed is in the advance position, yet the performance at retard is still quite good and altogether better than that of the Z.R.6. (18) Primary resistance .40 ohm at 18°C. This is much less than that of the Z.R.6. (19) Secondary resistance 3,200 ohms at 120°C. This is practically the same as the secondary of the Z.R.6. (20) Secondary milli-amperes Maximum 11.9 (armature horizontal) Minimum 8.1 ( " vertical ) These figures are a little higher than those for the corresponding positions on the Z.R.6. This machine was rather noisy, especially at high speeds, mainly due to a rattling and squeaking in the gears, but also partly a clicking noise from the contact breaker. EFC. | ||