INTERNAL COMBUSTION ENGINE CONTAINING SUCTION AIR HEATER

PURPOSE:To electrify an electric heater within a short duration in a suction passage which is formed in an engine body by forming a plurality of thin projections having a high thermal conductivity and a low flow resistance on the face of an inwall of the passage. CONSTITUTION:Many projections 20 are shaped on the inwall of a suction passage 3 which is communicated with a suction port 2 of a cylinder head 1, just before the suction port 2 in such a shape, columnar, pointed or trapezoidal, not to give a high resistance to mixture and are concentrated as thickly as required for heat-exchange. Heat of a combustion chamber 16 and that of cooling water in a water jacket 12, if an engine is of a water cooling type, are transmitted to the wall of the suction passage 3 so that the projections 20 are heated after operation of an internal combustion engine. Fuel which trickles down along the inwall of an intake manifold 17 in a layer fashion comes into contact with the projections 20 for atomization. An electric heater, providing an aid for atomization at cold temperatures, may be applied within a short duration.