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 comparison chart for a Bentley 4 1/4 Litre engine, contrasting standard turbulent and deturbulated cylinder heads.
| Identifier | ExFiles\Box 82\4\ scan0330 | |
| Date | 5th June 1936 | |
| SP{Mr Spinney} 30 BENTLEY 4 1/4 LITRE POWER COMPARISON BETWEEN STD. TURBULENT & DETURBULATED HEADS. (Le C. 5002) TESTS CARRIED OUT OPEN EXHAUST. ① DETURBULATED STD. CYL. HEAD TO Le C. 5002 (6.3:1) ② STD. TURBULENT CYL. HEAD E.B. 560 (6.5:1) STD. VALUES 1.6 DIA. INLET 1.4 DIA EXHAUST B.H.P. & M.E.P. R.P.M. ① M.E.P. ② ① B.H.P. ② 5-6-36 | ||