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).
The failure of Champion sparking plugs from a Falcon XI engine using doped fuel.
| Identifier | ExFiles\Box 35\4\ scan 003 | |
| Date | 17th March 1928 | |
| D/4/11. E.E.344. ROYAL AIRCRAFT ESTABLISHMENT. Report No.E.E.344. Investigation of the Cause of Failure of Champion Sparking Plugs Type R.11.V. Removed from Rolls-Royce "Falcon XI" Engine using Doped Fuel. -by- The Staff of the Ignition and Electrical Department. A.M.Reference:-789999/27/R.D.E.3. R.A.E.Reference:-S.F.374. 17th March,1928. D.{John DeLooze - Company Secretary} 1. Introductory. Six "Champion" sparking plugs type R.11.V. which had been removed as defective from a Rolls-Royce "Falcon XI" engine fitted in the "Wizard" aircraft were forwarded to the R.A.E. by AD/R.D.E. branch, Air Ministry, for examination and report. The engine has a compression ratio of 8:1 and runs at a speed of 2250 R.P.M. (normal). The fuel used was standard aviation spirit to which 10 cu.cms. of T.E.L. dope had been added per gallon. No benzol was used. 2. Description of Plug. (See Drawing No.E.E.1651). The plug is of the detachable porcelain insulated type with standard 18 m/m diameter on the body. thread The overall length is 2 5/8", reach 1/2". The central electrode consists of a nickel rod 0.040" diameter (19 S.W.G) and is cemented in to the insulator and further secured by means of a brass cap spun over the top of the insulator. The electrical leakage path between the central electrode and the plug body consists of a cupped surface of glazed porcelain. The length of the path is about 6 m/m.{Mr Moon / Mr Moore} The volume of the gas space within the plug is 0.3 cu.cms. It is not possible to adjust the gap between the plug points. 3./ | ||