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).
Page detailing heat balance and the effects of supercharging on octane number requirements, with a data table.
| Identifier | ExFiles\Box 140\1\ scan0224 | |
| Date | 28th March 1938 guessed | |
| -20- Heat Balance Over A Range Of Intake Manifold Pressure At 1000 R.P.M. The percentages of the heat supplied which were converted to work, absorbed by the cooling water, and dissipated in the exhaust are shown on Figures 36 and 37. The thermal efficiency was nearly constant over the entire range of intake manifold pressures. The percent of heat absorbed by the cooling water in general gradually decreased with a corresponding increase in percent heat lost in the exhaust gases as the manifold pressure was increase. These data provide some further indication that supercharging tended to blow fresh charge through the cylinder during the period of valve overlap. The observed increase in percent of heat in the exhaust and unaccounted for with increasing manifold pressure would be a logical result of loss of fresh charge in the exhaust. The Effect Of Supercharging On Octane Number Requirements The fuel octane numbers for incipient knock were determined for the 5.55 to 1 compression ratio supercharged engine at carburettor air temperatures of 80, 120, and 170 degrees Fahrenheit at an engine speed of 1000 r.p.m. Standard Cooperative Fuel Research Committee Reference Fuel C-9 plus lead was used as the fuel. The data are presented in Table IV below. Table IV. C.F.R. Motor Method Octane Number of Lead-Treated Reference Fuel Which Produced Incipient Knock at 1000 rpm. with 5.55 to 1 compression ratio. Intake Manifold Pressure, Carburettor Air Temperature. Inches of Mercury Absolute. 80°F 120°F 170°F.{Mr Friese} 29.0 78 - 80 77 - 79 80 - 81. 30.0 81 - 83 79 - 81 82 - 83. 32.0 84 - 86 83 - 84 84 - 86. 34.0 87 - 89 85 - 87 86 - 87. 36.0 88 - 89 87 - 89 - 38.0 89 - 90 - - 39.0 90 - 91 - - | ||