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).
Analysis of cylinder head temperatures and engine detonation characteristics under supercharged conditions.
| Identifier | ExFiles\Box 133\1\ scan0115 | |
| Date | 17th September 1936 | |
| -11- Hs{Lord Ernest Hives - Chair}/Ed.{J. L. Edwards}1/KW.17.9.36. These figures are, of course, purely representative, and are not intended to represent any point or any particular set of conditions. Cylinder Head. The point between the exhaust valves is easily the hottest (No.14), but it is a little difficult to separate the others. The next on the list, however, is probably the plug, and following this the group consisting of the point between the inlet valves, the two side positions, and the extreme edge on the exhaust side, are nearly the same. Speaking generally, the head appears to be of a fairly uniform temperature about 240°C. - with a hot spot of about 270°C. between the exhaust valves. Detonation. With the supercharged running, detonation curves were taken at constant speed, viz: 4,000 R.P.M. The boost was set to some given value, and the mixture weakened off until the unit just detonated at about 1 ft. Curves were then taken showing B.M.E.P. against fuel consumption at constant speed and detonation intensity, and the results, with temperatures, are shown in Figs. XXI to XXV, and XXVIII to XXIX. On removal of the head and piston after one such curve, there appeared to be a zone of high temperature radiating from the plug, and spreading out fanwise to embrace the exhaust valves. Detonation attack, however, showed on both head and piston as occurring just under the inlet valves. | ||