Combustion engine chamber

A structure of a chamber in a combustion engine comprising:

• a cylinder block of an engine having a cylinder in which a piston is reciprocatably disposed;
• a cylinder head of the engine disposed on the cylinder block;
• a chamber formed between a bottom surface of the cylinder head and a top surface of the piston;
• an intake port formed in the cylinder head for inducting air to the chamber;
• an exhaust port formed in the cylinder head for discharging exhaust gas from the chamber;
• an intake valve for selectably closing the intake port;
• an exhaust valve for selectably closing the exhaust port;
• a ring-groove portion, in which a piston ring is fitted, formed around a side-outer surface of the piston;
• a squish-area making portion, which is formed on the top surface of the piston, for making narrow space as a squish-area defined between the bottom surface of the cylinder head and the top surface of the piston located in top dead center;
• and
• an outer edge portion formed around the top surface of the piston except said squish-area making portion;
• and
• a land portion, which is formed around a side surface of the piston between said ring-groove portion and the top surface of the piston, having
• a squish-land portion formed between said ring-groove portion and said squish-area making portion, and
• a outer edge land portion which is formed between said ring-groove portion and said outer edge portion and is smaller than said squish-land portion in height.