10 15 20 25 988,378 injecting fuel into the air in the working space after the closing of the exhaust port. 2. An internal combustion engine as claimed in Claim 1 in which the inlet port is adjacent to one end of the working space and the ex- haust port adjacent to the other and the inlet port opens at the tennination of the expan- sion 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 change of, hot gas and air tends to be formed within the cylinder, with the hot gas layer adjacent the exhausr port, for expulsion of the layers in succession during the exhaust period. 3. An internal combustion engine as claimed in Claim 1 operating on the liquid fuel in- jection compression ignition cycle wherein the fuel is injected towards the end of the com- pression stroke. 4. An internal combustion engine as claimed in Claim 1 or Claim 2 in which the engine operates on the spark ignition principle and the fuel is injected into the air in the working space shortly after the closing of the exhaust port and substantially before the end of the compression stroke. 5. An internal combustion engine as claimed in Claim 3 in which the compression ratio is normal for a compression ignition engine and the expansion ratio is between 75: 1 and 100: 1. 6. The combination with an internal com- bustion engine as claimed in any one of the preceding claims of a combustion chamber arranged to receive the exhaust gases and scavenging air, means for injecting further fuel into the combustion chamber, and a tur- bine arranged to be driven by the products of combustion from the combustion chamber. 7. An internal combustion engine substan- tially as described herein with reference to the accompanying drawings. 8. The combination of an internal combus- tion engine and turbine substantially as des- cribed herein with reference to Figure 1 of the accompanying drawings. KILBURN & STRODE, Chartered Patent Agents, Agents for the Applicants. Leamington Spa: Printed for Her Majestys Stationery Ofce by the Courier Press1965. Published at The Patent Cities. 25, Southampton Buildings. London. W.C.2, from which copies may be obtained. 35 40 45