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, comparing two configurations.
| Identifier | ExFiles\Box 86\1\ scan0194 | |
| Date | 3rd 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. Graph curves: MIN. ADVANCE FOR MAX. POWER NECESSARY ADVANCE TO JUST AVOID DETONATION Vertical Axis (Left): 10, 20, 30, 40 Vertical Axis (Right): B.M.E.P. 90, 100, 110, 120 Horizontal Axis: R.P.M. 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000 | ||