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).
Instructions for modifications to a Phantom head to create a high compression, large valve version.
| Identifier | ExFiles\Box 14\3\ Scan089 | |
| Date | 29th August 1933 | |
| To RHC.{R. H. Coverley - Production Engineer} from Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}2/KT.29.8.33. HIGH COMPRESSION LARGE VALVE HEAD. Please have a Phantom head made with modifications shown on attached drawing Hs.{Lord Ernest Hives - Chair}1012. (1) Ceiling of combustion chamber lowered .164", and valve guide sockets lengthened by .164". (2) Valves .164" longer in stem fitted. Hs.{Lord Ernest Hives - Chair}1013 & Hs.{Lord Ernest Hives - Chair}1014. (3) Valve guides to Hs.{Lord Ernest Hives - Chair}1117 and Hs.{Lord Ernest Hives - Chair}1118 lengthened by .164". (4) Provision for 14 mm. plugs instead of 18 mm. with centre line of plug lowered as shewn on drawing. (5) Double taper valve springs. Hs.{Lord Ernest Hives - Chair}664 Outer spring. Hs.{Lord Ernest Hives - Chair}665 Inner spring. EX.8895 Crumpet retainer. EX.8896 Top spring cap. EX.8897 Bottom spring washer. Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} | ||