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).
Conclusion on the performance of brass and tungsten for jump spark points and the effects of distributor ventilation.
| Identifier | WestWitteringFiles\H\November1921\ Scan9 | |
| Date | 7th November 1921 | |
| -2- Contd. It is concluded that brass is not satisfactory for jump spark points. Tungsten has performed very favourably and carbon remains to be tried. Evidently distributor ventilation does not seriously affect platinum sparking points, but it does affect the operation of the rocker mechanism as regards lubrication. If the rusting were due to the moist atmosphere, ventilation would be more likely to cause than to prevent it. It seems unlikely that the small H.T. sparks are sufficient to cause it and experiments are in hand to find the effect of primary current surges as previously reported (AB.29/7.11.21). Sgd. F.J.A. | ||