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).
Flight tests detailing ignition failures and issues with different models of Champion spark plugs.
| Identifier | ExFiles\Box 35\3\ scan 191 | |
| Date | 1st February 1928 | |
| To RG.{Mr Rowledge} from Hs{Lord Ernest Hives - Chair}/TAG. c. to Mr. Wilkins A.I.D. c. to Wor.{Arthur Wormald - General Works Manager} EP.{G. Eric Platford - Chief Quality Engineer} c. to AID. Messrs. De Havillands. Handwritten: X4196 Hs{Lord Ernest Hives - Chair}/TAGL/LGA.2.28. RR. DH.{D. Henderson - Showroom} 9a. Handwritten: X4196 .X3626 Y2810 PART 11. of Report on Flight Tests carried out on the above machine. Flying. In Part 1. we dealt with High Oil Temperatures and Over-oiling - in this report it is intended to deal with - Ignition failures. The engine was fitted with Champion R.11 plugs. These plugs are the very cool running type and therefore prone to over-oiling. This over-oiling caused considerable trouble and we then fitted Champion R.12.V. This is the next stage * 'hotter' plug. These plugs were used for 20 hrs. 40 mins. flying, 6 hrs. 45 mins. ground running, after which they were removed to enable an experimental set to be tested - Champion model R-1-V which are really a shorter type body of the R.12 model. During the 20 hrs. 40 mins. these plugs were not cleared but only had the points or gaps adjusted. They were O.K. as regards the oil resisting qualities. There are one or two objections to this plug, which are - (1) Not being able to adjust the spark gaps beyond a very limited point. (2) Owing to the fact that there are two joints to make when assembling this plug after cleaning (joints between the central electrode insulation and the plug body) makes it become a skilled job to clean them as the slightest leak at these joints causes immediate plug failure. We also have experienced trouble through condensation both outside on the insulation and inside on the plug points. contd :- | ||