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).
Description of the combustion chamber design, piston crown protuberance, and valve arrangement.
| Identifier | ExFiles\Box 147\2\ scan0180 | |
| Date | 21th December 1939 guessed | |
| being shown at C. A combustion chamber C¹ is formed in the head of the cylinder the walls of which are shown at C² being parallel to the axis of the cylinder and in plan of oval or elliptical shape (see Figure 2). On the crown of the piston is formed a protuberance D also oval in plan (see Figure 2). The side walls of this protuberance are parallel to the axis of the cylinder and therefore to the wall C² of the combustion chamber C¹. The cross section area of the protuberance D being only a little smaller than that of the combustion chamber C¹ the walls of the protuberance D will at top dead centre as shown lie close to the wall C² of the combustion chamber. The combustion chamber is aspirated by two overhead valves one of which is shown at E.{Mr Elliott - Chief Engineer} The ignition plugs are not shown. It will be seen that there is no straight pathway between any two particles of gas one of which is in the combustion chamber and one in the space between the projecting portion C of the head and the top of the piston B 5. | ||