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).
Technical memo detailing improvements and considerations for the battery ignition system on the 'Coshawk II'.
| Identifier | ExFiles\Box 52\3\ Scan023 | |
| Date | 23th November 1921 | |
| X.4430 Extract from R10/G25.11.21. X.3485 RE VISIT OF MESSRS. HIVES & HALDENEY TO WEST WITTERINGHenry Royce's home town WITH "COSHAWK II" - 23rd NOVEMBER 1921. X 4430 (6) BATTERY IGNITION. With regard to the condenser, the factor given for mica insulation is greater than for the paper, and as the thickness of the mica is only slightly greater than that of the paper, I think we ought to get a better capacity than stated, for a practical mica condenser. I think we should put more effort into obtaining the materials we require, (paper, which I believe should be waxed). There should be some vents in the high tension chamber for the purpose of getting rid of the nitric acid vapour. The low tension wire in passing down from the bakelite elbow guides gets in the way of the left hand clip holding the high tension moulding. I think we should endeavour to get this behind the tower in some way. The car brought here had the correct running position for the hand control at the top of the quadrant, but I should like this to be arranged lower down so as to provide a range for varying strength of mixture etc. The rocker for the battery ignition is intended to be a steel pressing, that seen on the car was in brass. There should be a good pressure on the rocker spring. The Americans say that the tungsten points will not last clean without a strong spring pressure. I hope that we shall be able to use this ignition on the 40/50 HP. chassis. It promises to be an excellent unit which, under manufacturing conditions, should be of reasonable cost. This ignition is reported to run the engine extremely well, owing to the more suitable and accurate advance and control of the ignition timing, which one found incapable of improvement by hand control at varying speeds. | ||