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).
Résumé of the development of various sparking plugs for new aero engines.
| Identifier | ExFiles\Box 58\2\ Scan117 | |
| Date | 8th June 1934 | |
| E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Wox. c. to By.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to Lr.{Mr Ellor} c. to Lp.{Mr Lappin} c. to Mr.Jaques. A.I.D. 81912a. Hs{Lord Ernest Hives - Chair}/Wst.9/MA.8.6.34. AERO ENGINE SPARKING PLUG DEVELOPMENT. We give below a résumé of the development of various sparking plugs for our varied requirements on our new aero engines. Goshawk Engines (14 mm.) The only satisfactory plug for these engines until quite recently has been the K.L.G. type 744. This plug will even stand a limited amount of full throttle work without overheating and it has a good oil factor. The Lodge Co., have been work for some time to produce a plug as satisfactory as the K.L.G.744, and after several unsuccessful attempts they have at last supplied us with a 14 mm. plug, type X400, which has satisfactorily completed a type-test with results on the average slightly better than the 744. On both types of plugs, electrode erosion is the worst factor, particularly with lead fuel, and we are continually testing out experimental Lodge & K.L.G. plugs on the single cylinder engine to overcome this trouble. So far the results have been negative. A plug which appears to offer a partial solution to this difficulty is the K.L.G.822. This plug is similar in construction to the 'Wizard' plug used by 'Imperial Airway' the difference being that we have retained the same insulator shape as the 744 and altered the shape of the central electrode to reduce the plug operating voltage. The operating voltage of the ordinary 'Wizard' plug is very high. This point is/importance for high altitude work. of | ||