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 difficulties of using bottom-seated sparking plugs on Merlin engines and a proposed solution.
| Identifier | ExFiles\Box 58\2\ Scan296 | |
| Date | 24th February 1936 | |
| WST seeme Y6000 Hs{Lord Ernest Hives - Chair}/Wst. c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} E/Bn.{W.O. Bentley / Mr Barrington} E/Fsn. E.4/HP.24.2.36. Sparking Plugs on Merlin Engines. Referring to your memo Hs{Lord Ernest Hives - Chair}/Wst.7/MA.27.1.36, the proposal to use bottom seated plugs is rather revolutionary and will be treated as a development if considered suitable for application. There is a fundamental difficulty however that in the case of deeply buried plugs, as on the inlet side of the Merlin "E", and on sleeve valve heads, the joint washer does not come away with the plug, in fact its tendency is to spread itself and remain locked in position. We are, therefore, instructing some of the existing type of adapters in N.C.M. steel for test on the existing engines, as this does not change any of the features affecting plug operation, and if effective would be a very easily applied solution of the difficulty. The internal threads of the adapter not covered by the screwed portion of the plug are to be machined away. E.{Mr Elliott - Chief Engineer} | ||