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).
Performance graph for a 25/30 HP Turbulence Cylinder Head, showing B.M.E.P. and ignition advance against R.P.M.
| Identifier | ExFiles\Box 103\4\ scan0163 | |
| Date | 27th April 1936 guessed | |
| 25/30 H.P. CYLINDER HEAD (TURBULENCE) ① CYL HEAD E.60660. C/R 6:1 ② " " MOD. TO LEC. 5002 C/R 5.86:1 INDUC'N PIPE E.60874 STROMBERG CARB. LEC. 4883. MIN ADVANCE FOR MAX POWER NECESSARY ADVANCE TO JUST AVOID DETONATION R.P.M. B.M.E.P. | ||