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).
Letter discussing sparking plug gap size specifications and associated tooling costs with supplier Lodge.
| Identifier | ExFiles\Box 79\1\ scan0081 | |
| Date | 3rd January 1917 | |
| COPY To EP.{G. Eric Platford - Chief Quality Engineer} } from BY.{R.W. Bailey - Chief Engineer} EH. } 3rd. January 1917. BY12/G3117. X.601 RE SPARKING PLUGS. We cannot seem to get the above matter settled. I am sending you an extract from the Lodge letter of the 2nd. January, and would like you to get together and agree as to which of the proposals you are prepared to adopt. The position is that they can give us the gap size to minus .005"; that is, by our original order, based upon your request, they will give us a gap between .015 and .010. This, however, I understand you objected to on the plea that the .010 was too small. They therefore say that they can give us .020 maximum to .015 minimum, but they cannot give us the variation gap by dividing the allowance plus and minus. I would point out that they have already completed the tools to give us the gap suggested in paragraph 2 - .015 to .010, and we shall have to pay them for the new tools if we require them to be made as .020 to .015. BY.{R.W. Bailey - Chief Engineer} Extract from Lodge letter of 2nd. January 1917 "You now suggest a theoretical gap of .0175" with an allowance of +or- .005" this would represent a minimum gap of .0125" which we take it is less than you care to go. If .015" is the minimum gap you are prepared to allow then we think it is best to adhere to the present theoretical gap of .020". We have already completed the tool to make the theoretical gap of .015" as per your order BK.{A. Birkett - Commercial Manager}938, and we have all the necessary nickel rings made for your new order from this new tool. These rings, however, we are prepared to alter if required, but we should, of course, have to charge you with the new tool." | ||