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 'Ramp' and standard cylinder heads, detailing constructional differences and detonation test setup.
| Identifier | ExFiles\Box 133\2\ scan0060 | |
| Date | 26th July 1934 | |
| -2- (3) The plug position is unalterable for use in multi-cylinder unit. (4) Tests are shortly to be carried out with a smaller inlet valve, which will increase the turbulence at this point and indicate the value of the better orifice co-efficient of the Ramp head. A modified head, designed to give more turbulence at end of compression, will shortly be available for test. Detailed Report. Comparison of Ramp & Std. Heads. Constructional Details :- Ramp. Std. Compression Ratio (except where stated):- 6.59 6.40 Inlet valve dia. 1.500" 1.400" Exhaust valve dia. (normal) 1.300" 1.300" Area past inlet valve. 1.677 sq" 1.450 sq.in. " " exhaust " 1.160 " 1.160 " Valve lift. .375" .400" Inlet port dia. 1.500" 1.350" Exhaust port dia. 1.350" 1.350" Detonation. For the purpose of comparing the detonation of the two heads, the comp. ratio of the "Ramp" was reduced to that of the std. head. viz: 6.40. This was effected by fitting a slightly thicker gasket under the "Ramp" head. | ||