Glow plug engine

A glow-plug engine comprising:

• a combustion chamber to which a premixed air-fuel mixture is introduced,
• a piston that compresses the premixed air-fuel mixture introduced in the combustion chamber, and
• a glow-plug with a tip end section that is exposed into the combustion chamber for igniting the premixed air-fuel mixture compressed by the piston;
• wherein the glow-plug protrudes toward a top surface of the piston in the combustion chamber, and the tip end section of the glow-plug is placed in a prescribed region near the top surface of the piston when the piston is positioned at a top dead center, the prescribed region being determined to set a starting point for combustion of the premixed air-fuel mixture near the top surface of the piston.