Abstract: A split cycle internal combustion engine having located wholly within the combustion chamber (13) of the firing cylinder (10) and spaced from the walls thereof a hollow dome (14) with the closed head of the dome (14) adjacent to the head (11) of the firing cylinder (10) and the open base of the dome (14) nearer to the power piston (12), a nozzle (24) directing air from a compressor around the interior wall of the dome (14), nozzle (24) directing fuel into the dome (14) after all the air has entered the dome (14) and a nozzle (25) for igniting the fuel/air mixture when the temperature of the dome (14) is insufficiently high for ignition. An inwardly directed flange (17) extends around the open base of the dome (14) to form a channel (18). It is preferred that the engine operates at very high pressures, the compressor is multi-stage.

Abstract: The invention concerns novel compounds of the formula I ##STR1## wherein: m is an integer selected from 1 to 4;n is zero or an integer selected from 1 to 4;X are selected from halogen, nitro, cyano, alkyl, substituted alkyl, hydroxy, alkoxy, alkylthio, sulfamoyl, substituted sulfamoyl, amino, substituted amino, the group --(CH.sub.2).sub.p C(.dbd.A)Z in which p is zero or one A is oxygen or sulfur, and Z is hydrogen, hydroxy, alkoxy, alkylthio, alkyl, substituted alkyl, amino or substituted amino, the group --NHC(.dbd.B)NR.sup.7 R.sup.8 in which B is oxygen or sulfur and R.sup.7 and R.sup.8 are hydrogen or alkyl;R.sup.1 is selected from hydrogen, acyl and an inorganic or organic cation;R.sup.2 is selected from alkyl, substituted alkyl, alkenyl, haloalkenyl, alkynyl and haloalkynyl;R.sup.3 is selected from alkyl, fluoroalkyl, alkenyl, alkynyl, and phenyl; andR.sup.4 is selected from hydrogen, halogen, alkyl, cyano and alkoxycarbonyl.

Abstract: The high pressures in the combustion chambers of split cycle internal combustion engines require higher voltages to be applied to spark plugs than are utilized in conventional Otto cycle engines, with the result that the working life of the spark plugs is shortened. The present invention overcomes this difficulty by directing into the combustion chamber a pilot charge consisting of a spark-ignitable fuel in admixture with compressed air at a pressure below 2000 kPa, followed, after the pilot charge has been ignited, by a main charge of fuel and compressed air at a pressure higher than 2000 kPa.

Abstract: A split cycle internal combustion engine of the kind described in U.S. Pat. No. 3,408,811, in which the only ignition means is heat supplied from an external source such as an incandescent tube or a heater for the admitted air and which advance and retardance of the ignition is effected by automatically controlling the timing of the admission of fuel and the heated air to the combustion chamber in response to the load upon the engine. This is achieved by lengthening or shortening a pivoted telescopic lever attached to the cam followers for the fuel pump and the transfer valve admitting the air. By driving the low pressure stage of the compressor from a different throw of the crankshaft from the higher pressure stages, a compact and well-balanced engine may be designed.