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).
Engine condenser positioning and size to protect platinum points, and the decision to use electric starters post-war.
| Identifier | ExFiles\Box 37\1\ scan 006 | |
| Date | 10th July 1917 | |
| Contd. -2- R2/B10.7.17. may benefit the running of the engine considerably. Regarding the position of the condenser, I think this should be between the beginning end of the primary winding and the earth contact on the contact maker. This will avoid the rush back of current having to pass through the non-inductive high resistance. Remy appears across the contact breaker as at present. To avoid damaging the platinum on the make and break( and also to reduce the risk of damage to the platinum points on the ordinary trembler coil) I suggest that the condenser be made larger than is necessary for the greatest length of spark. That is to say, one feels, that by gradually increasing the capacity of the condenser, the length of the secondary spark would grow to a maximum, then gradually reduce. Now one feels as though this size of condenser is not necessarily the best one for preserving the life of the contact points, which I presume, would show less and less sparking as the condenser was increased in capacity. It will be necessary to make the observations of the condition of the platinum points and the size of the condenser at various speeds, up to an engine speed of 3,000 revs. when our 6 point contact maker would be running at 1500 revs. We have decided that all chassis after the war will have electric slef starters, and it would seem that this form of battery ignition would be preferable to the one we are at present using. Not only would there be a considerable saving in cost, but there should be no troublesome trembler and the battery and the magneto ignitions can be exactly Contd. | ||