PATENT SPECIFICATION DRAWINGS ATTACHED 988378 No. 5333/62. Na. 30754/62. Index at acceptance: F1 B(1D2, lDlO, lG4P, 1G4Z); Fl Q(l, 11B2A, 11B4C, 11135) Int. Cl. : -F 02 b/IF 02 g, 1 10 15 20 25 30 35 40 COMPLETE SPECIFICATION Improvements in and relating to Internal Combustion Engines 1, ERNEST EDWARD CHATTEETON, a British Subject, of 24 Wood Lane, Ruislip, Middle sex, do hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement:-~ This invention relates to reciprocating in- ternal combustion engines operating on a 2- stroke cycle and either of the liquid fuel in- jection compression ignition type or of the fuel injection spark ignition type and has for an object to provide an engine which will have high efciency and in which adequate cooling of the necessary parts will be facilit- atedi According to the present invention in a reciprocating internal combustion engine which operates on the Z-stroke cycle with air scavenging the inlet port is arranged to open before the exhaust port and the opening periods of the inlet and exhaust ports are such that the expansion ratio of the engine is greater than the compression ratio and with that at the end of the expansion period the pressure in the working cylinder is substan- tially below that of the air in the source from which the inlet port receives its air sup- ply, and means are provided for injecting fuel into the air in the working space after the closing of the exhaust port. In one arrangement the inlet port is adjacent to one end of the working space and the exhaust port adjacent to the other and the inlet port opens at the termination of the expansion period, before the exhaust port opens so that air begins to enter the cylinder through the inlet port before the exhaust port opens and a stratied charge of hot gas and air tends to be formed within the cylinder, with the hot gas layer adjacent the exhaust port, for expulsion of the layers in succession during the exhaust period. In the case where the engine operates on the liquid fuel injection compression ignition cycle the fuel is preferably injected towards the end of the compression stroke. The en- gine may also operate on the spark ignition principle and in which case the fuel is in- jected into air in the working space shortly after the closing of the exhaust port and sub- stantially before the end of the compression stroke. When the engine operates on the compression ignition cycle preferably the com- pression ratio is normal for a compression ignition engine and the expansion ratio is, for example 75:1 or higher. In any case the engine may be used in combination with a combustion chamber arranged to receive the exhaust gases and scavenging air, with means for injecting fur ther fuel into the combustion chamber and a turbine arranged to be driven by the pro- ducts of combustion from the combustion chamber. The invention may be carried into prac- tice in various ways but one specic embodi- ment as applied to single cylinder engines will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a cross-sectional elevation of a form of 2stroke engine according to the pre- sent invention in combination with a turbine; Figure 2 is a diagrammatic representation of the operating cycle of the 2-stroke engine of Figure l; The engine shown in Figure 1 comprises a crank case indicated at 10 and consists of an upper section 11 joined to a lower section 12 by anges 13 and 14 respectively on each section. Attached to the upper section of the crank case is a cylinder block 15 contain- ing a cylinder liner 16 around which extends an annular inlet manifold 17, and provided with a number of circumferentially spaced Date of ling Complete Specication (under Section 3 (3) of the Patent: Act I949) May I0, I963. Application Date Feb. [2. 1962. Application Date Aug. l0, I962. Complete Specication Published April 7, [965. Crown Copyright I965. 45 50 55 60 65 70 75 80 85