Piston for internal combustion engine

A piston for a compression ignition engine, comprising:

• a crown portion having an outer diameter and an inner diameter wherein a ratio of said inner diameter to said outer diameter is greater than 0.65;
• a reentrant portion being connected with said crown portion;
• a torroidal portion being connected with said reentrant portion, said torroidal portion defining a maximum bowl depth;
• a floor portion being connected with said torroidal portion wherein the floor portion has a floor angle of 65 degrees or greater;
• a recess transition portion being connected with said floor portion;
• and
• a recess portion about a central axis of the piston, said recess portion being connected with said recess transition portion, said recess portion having a recess depth wherein said maximum bowl depth is greater than said recess depth.

A piston for a medium bore, compression ignition engine, comprising:

• a central axis;
• a crown portion positioned about said central axis, said crown portion having an outer diameter of about 105 mm and an inner diameter wherein a ratio of said inner diameter to said outer diameter is between about 0.65 and 0.75;
• a reentrant portion being connected with said crown portion, wherein said reentrant portion having a reentrant angle of about 63 to 68 degrees;
• a torroidal portion being connected with reentrant portion, said torroidal portion defining a maximum bowl depth;
• a floor portion being connected with said torroidal portion wherein the floor portion has a floor angle of about 65 to 70 degrees;
• and
• a recess portion about the central axis of the piston, said recess portion being connected with said floor portion, said recess portion having a recess depth wherein said maximum bowl depth is greater than said recess depth, said recess portion is a partial spherical surface, and a ratio of a recess diameter to the inner diameter being about 0.09.