Internal-combustion engine with catalyst (porous structure) to promote combustion [57]: 11-cylinder head; 11A,11B-poppet valves; 12-piston; 13-cylinder; 14-recess; 15-piston crown; 16-fuel injector; 17-nozzle; 18-fuel jets; 19-mounting ring; 20-screws; 21-gauze disc; 22-hole; 23-vertical gauze sheet (catalytic); 24-liner; 25-edge; 26-wire; 27-screws; 28-cutaway.