Issues with magneto ignition, coil safety, and spark plug gaps on 25 HP and 45 HP cars.
| Identifier | ExFiles\Box 164\5\ img023 | |
| Date | 23th January 1931 | |
| X6058 Hs. {Lord Ernest Hives - Chair} EFC. {E. Fowler Clarke - Electrical Engineer} EP. {G. Eric Platford - Chief Quality Engineer} ) FROM R. {Sir Henry Royce} E. {Mr Elliott - Chief Engineer} RV. ) (At Le CanadelHenry Royce's French residence) c. SG. {Arthur F. Sidgreaves - MD} Wor. {Arthur Wormald - General Works Manager} PN. {Mr Northey} R2/M23.1.31. X.6097. X.6098 CAR WORK - MAGNETO IGNITION X.6058 X.8970. It is understood that both the 25 HP. and 45 HP. cars will start on the magneto ignition if the battery and starting motor are normal. Also that probably owing to our battery distributor the 25 HP. does not run backwards but starts forwards even by a spark on the make side while moving backwards (recoil). If the 25 HP. is possible perhaps we ought to be able to make the 45 HP. also. If not what would be the cost of a hand magneto? For some time the American cars carried a spare coil when touring (I believe I can remember hearing this to be so). I believe coils break down because there is no proper safety gap. Under certain circumstances the secondary EMF. may be very high indeed. If this is so it ought to be limited by a safety gap or the coil so insulated as to stand the maximum EMF. on open circuit for a long time, as may occur with certain condition of plugs etc. Does our jump spark distributor increase the stress upon the coil insulation? I have said elsewhere that I do not approve of more secondary turns. I am in definite favour of plugs set with closer points - i.e. between .015" and .020" - i.e. 4 mm. gauge for contact maker. Even .025" is too great and .030" very excessive, and I think the cause of much of our trouble here and in U.S.A. for some years, in complaints of cars missing fire first on magnetos, (which had short safety gaps) and more recently on battery ignition misfires on 20 HPs. {Horace Percy Smith - Experimental Factory Mgr} If the foregoing is incorrect will Hs. {Lord Ernest Hives - Chair} and EFC. {E. Fowler Clarke - Electrical Engineer} point out my errors. R. {Sir Henry Royce} | ||
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).