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).
Graph showing the relationship between compression ratio and octane number for various engines.
| Identifier | ExFiles\Box 89\1\ scan0171 | |
| Date | 28th November 1935 guessed | |
| RELATION BETWEEN COMPRESSION RATIO & OCTANE N° FOR VARIOUS ENGINES. Y-AXIS LABELS: C.F.R. MOTOR METHOD OCTANE NUMBER X-AXIS LABEL: COMPRESSION RATIO LEGEND: C.F.R. ENGINE (MOTOR METHOD.) TWO S.V. WATER COOLED CYLINDERS TYPICAL OF AMERICAN MOTOR CAR PRACTICE GRAPH ANNOTATIONS: .06 RATIO PER O.N. .15 RATIO PER O.N. | ||