An internal combustion engine and ignitor therefore is provided. The ignitor has an insulator extending between a nose end and a terminal end with an electrode extending outwardly from the nose end to ignite an air/fuel mixture with a cylinder chamber. A terminal extends from the terminal end and is configured in electrical communication with the electrode. A metal shell surrounds at least a portion of the insulator. The metal shell is free of external threads for attachment to a cylinder block. A connecting wire extends from the terminal for electrical communication with a power source. A tube has a lower end that receives the terminal end of the insulator therein. The tube extends about the connecting wire to an upper end opposite the lower end. The lower end of the tube compresses the shell into fixed relation within the opening of the cylinder head.