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 from L.S.P. Co. Ltd. discussing specifications and testing proposals for various spark plug models.
| Identifier | ExFiles\Box 79\1\ scan0133 | |
| Date | 12th September 1918 | |
| Page 2 L.S.P. Co. Ltd. Date 12/9/18 Messrs.Rolls-Royce, Ltd. the 17th inst., when the writer will be calling at your Works as arranged. With reference to these plugs:- D11 is the latest type of the Model D detachable plug, of which you tested a number some few months ago. We have since made great improvements in the design, and if you require a detachable plug for your engines we submit this model with considerable confidence. The Model KR5 plugs that we are sending are, we consider, a better construction than the previous KR5 plugs which you have just tested and returned to us, and the idea in submitting this pattern is that it should replace the present KR3. The Z" & Z10 are practically similar plugs, both being fitted with our new steatite insulators, the only difference between the two models is in the shape of the insulator at the sparking end of the plug, and the thickness of the central sparking point. Our idea in sending 1 Doz. of each is that you would test the complete 2 Doz. on one engine simultaneously. If this steatite insulator is satisfactory on your engines it has certain | ||