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).
Suitability of experimental Super Reach Spark Plugs for different cylinder heads.
| Identifier | ExFiles\Box 162\3\ img220 | |
| Date | 14th May 1941 | |
| To Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} from Jnr.{Charles L. Jenner} c. to Rm{William Robotham - Chief Engineer}/RC.{R. Childs} Jnr.{Charles L. Jenner}1/SW.14.5.41. B.60. Super Reach Spark Plug. In regard to the Experimental plugs, which are on order, these are suitable for the "ORIGINAL" cylinder head. In the case of the "INTERMEDIATE" head (the one we are losing interest in because of roughness), there is the possibility of the end of the plug fouling the exhaust valve at full lift. I cannot say definitely, because it is dependant on the compression ratio used and the accuracy of the spark plug hole angular drilling. Jnr.{Charles L. Jenner} | ||