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).
Internal memorandum discussing the suitability and failure of various ignition plugs for 'Kestrel' engines under different boost conditions.
| Identifier | ExFiles\Box 58\2\ Scan197 | |
| Date | 15th May 1935 | |
| V6000. BY c.c. Lp{Mr Lappin} Hs{Lord Ernest Hives - Chair}/Wst Hs{Lord Ernest Hives - Chair} Mr.Jaques (A.I.D) EP{G. Eric Platford - Chief Quality Engineer}14/MH.{M. Huckerby}15.5.35 re IGNITION PLUGS FOR "KESTREL" ENGINES ------------------------------------ With reference to Hs{Lord Ernest Hives - Chair}/Wst.6/MA.13.5.35, we do not feel that the present serious position as regards satisfactory plugs for our engines is realised. The only satisfactory tested plug suitable for 5 lbs boost so far appears to be the K.L.G.V9 type, and yet it would appear that the K.L.G. V7/2B plug is to be recommended for this use, although we have no experience of this being satisfactory, either on the test beds or in service. At present the actual plug the Services are using appears to be the Lodge A2/2, also the K.L.G. V7/1, and unless some definite action is taken at once we feel sure that our present engines with the increased take-off boost will be run with these plugs fitted. It has already been demonstrated that the Lodge A2/2 plugs in the Kestrel VI engines used in the Fairey "Hendon" at Martlesham for 6 lbs boost caused the engines to fail; as a matter of fact, these plugs are also giving trouble even for 3½ lbs boost engines - in fact they are actually failing on our test beds for 1½ lbs boost conditions. Apart from the fact, therefore, that the engines may give trouble with these plugs fitted, we must also consider the harm done to the engine by it being run under pre-ignition conditions and which may be the start of a failure which may take place later in its life. It is essential that when instructing for increased take-off boost that the instructions should include the type of ignition plug to be used, i.e. one which has been tested as satisfactory, approved and recommended. EP{G. Eric Platford - Chief Quality Engineer} | ||