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).
Selection, purchase, and testing of different brands of spark plugs for various car markets.
| Identifier | ExFiles\Box 35\3\ scan 135 | |
| Date | 2nd February 1921 | |
| To BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} c. to CJ. c. to Hs.{Lord Ernest Hives - Chair} c. to EF. c. to Hm.{Capt. W. Hallam - Head Repairs} c. to Fn. c. to H.{Arthur M. Hanbury - Head Complaints} c. to R.R. of America Inc. (for the attention of CY) X.4196 R8/C22.2.21. X.1812 RE SPARKING PLUGS X.4295 X.4196 X.4313 X.2635 With reference to your BY11/P14.2.21, a few days ago I sent a memo recommending Champion Plugs as the standard for U.S.A. cars and Mercury standard for English built cars. I agree that cars for U.S.A. and Canada should be despatched without plugs, but dummies to keep out dirt, and certainly agree to ordering 500 Champion @ 5d. each in U.S.A. and 1,000 Mercury @ 1/2 each or less, at our works. I consider the Mercury the better from my observations, but this is subject to, and over-ruled by practical experience. Lodge mica porcelain ones such as I have used, should be discouraged at once as quite unsatisfactory. My little pump engine is excellent for testing the value of plugs from a sooting-up point of view, as the combustion chamber is divided into two; one part where the plug is, gets the over-rich mixture. This is further diluted with extra air (by valve) in part of the combustion chamber where the piston is. Thus, all cool working plugs are soon sooted up. Mercury, Champion and (Lodge with porcelain collar) all clean themselves. The old Bosch (four pointer) Lodge (mica) K.L.G.(mica) etc. fail in a few minutes hours quite consistently. Contd. | ||