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).
Power test results for an 8.1 Litre Phantom engine, comparing 5.5:1 and 6:1 compression ratios.
| Identifier | ExFiles\Box 92\2\ scan0187 | |
| Date | 8th December 1938 | |
| HS.{Lord Ernest Hives - Chair} 1227 8.1 LITRE PHANTOM POWER TESTS (OPEN EXHAUST) COMPARISON BETWEEN 5.5:1 AND 6:1 COMPRESSION RATIO (A) 6:1 RATIO CYL HEAD - LARGE INLET VALVES TO (Ex. 12011) - 2.000 DIA THROAT 14 M/M SPARK PLUGS KLG 765A - DOUBLE TAPER VALVE SPRINGS (B) 5.5:1 RATIO CYL HEAD - STD INLET VALVES (E82458) 18 M/M SPARK PLUGS SINGLE VALVE SPRINGS 2 - 1 7/8 BORE SU CARBS - 1 1/4 BALANCE HOLE BHP MEP (LBS □") RPM TIMING: 020 O'L'CE IO 6° BTDC IC 48° PBDC EO 58° BBDC EC TDC 8-12-38 | ||