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).
Comparison of Kestrel and Bentley ramp heads, showing performance curves and valve area data.
| Identifier | ExFiles\Box 133\2\ scan0049 | |
| Date | 4th July 1934 | |
| Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}11/KW.4-7-34 KESTREL AND BENTLEY RAMP HEADS INLET VALVE AREA INLET SQ IN/CU IN EXHAUST VALVE AREA EXHAUST SQ IN/CU IN BENTLEY. STD .039 .033 RAMP. .045 .033 KESTREL STD .036 .025 RAMP. .036 .025 AREA COMBUSTION CHAMBER PER SWEPT VOLUME .30 SQ INS/CU INS FOR BOTH ENGINES BOTH CURVES 6.1/1 C/R.{Sir Henry Royce} KESTREL RAMP BENTLEY RAMP I.M.E.P. 170 160 150 140 130 R.P.M. 1200 1600 2000 2400 2800 3200 3600 4000 | ||