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).
Modification drawing for a cylinder head to reduce the compression ratio.
| Identifier | ExFiles\Box 19\7\ Scan151 | |
| Date | 28th October 1952 | |
| HS{Lord Ernest Hives - Chair} 747 MODIFICATION TO CYL. HEAD ALREADY MADE MACHINE TO THESE DIMENSIONS. OTHER DIMENSIONS SEE (E100578) 1.00 RAD 2.825 3.000 REDUCTION OF COMPRESSION RATIO FROM 6.5 TO 6.0 : 1 MACHINE TOP FACE AND RECUT VALVE SEATS INLET EXHAUST .950 +.0 -.5 2.000 ± .5 | ||