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).
Proposal to order improved and ventilated magnetos from Messrs. North & Sons for the 40/50 HP and 20 HP chassis.
| Identifier | ExFiles\Box 65\3\ scan0361 | |
| Date | 8th April 1929 | |
| O.O. c. Hs.{Lord Ernest Hives - Chair} c. EFC. c. Mx.{John H Maddocks - Chief Proving Officer} X 7791 Ry14/G18.4.29. X 7792 X 7790. CHASSIS MAGNETOS. Messrs. North & Sons have developed improvements in both types of their magnetos which we use on chassis. We therefore propose that we should order the following magnetos from them :- 1/- 40/50 HP. CHASSIS 6 EW.6A magnetos to be used on the experimental cars. These have improved windings and ventilated low tension contact covers, giving a better spark range and generally all round better performance. 2/- 20 HP. CHASSIS They have developed a 20 HP. type magneto avoiding the use of the sleeve and introducing the armature of the EW.6A. We require three of these magnetos and again for use in the Experimental Department. In addition to the foregoing we should order 12 low tension contact covers to be ventilated to approved plan discussed between us. These covers to be handed to Mr. Maddocks for him to try same out on cars and decide whether the slot for ventilation allowed noise to escape more easily from the interior of the contact breaker. The object of the ventilation is to ensure that no contaminated air containing oil or petrol vapour shall be imprisoned in the contact breaker. The ventilation will ensure air passing regularly, and therefore Messrs. Norths state that it will definitely prevent the isolated instances we encounter of platinum points burning away quickly. They state that provision of ventilation on three other chassis for which they supply magnetos has entirely eliminated the trouble, whereas before the introduction of the ventilation they were involved in a very serious difficulty, so many platinum points broke down in the course of a few weeks running. Ry. | ||