Monolithic galleryless piston and method of construction thereof

A galleryless piston for an internal combustion engine, comprising:

• a monolithic galleryless piston body extending along a central longitudinal axis along which said piston reciprocates in a cylinder bore of an internal combustion engine, said piston body having an upper wall forming an upper combustion surface with an annular ring belt region depending from said upper combustion surface for receipt of at least one piston ring;
• a pair of skirt portions depending from said ring belt region to facilitate guiding the piston within a cylinder bore and having a pair of pin bosses providing a pair of laterally spaced pin bores aligned along a pin bore axis for receipt of a wrist pin;
• said upper combustion surface having first and second portions, said first portion extending annularly along an outer periphery of said upper wall and said second portion forming a combustion bowl depending radially inwardly from said first portion;
• said upper wall having an undercrown surface formed on an underside of said combustion bowl directly opposite said second portion of said upper combustion surface, wherein said combustion bowl has a maximum combustion bowl diameter and said undercrown surface having a complete openly exposed projected surface area that has a diameter that is at least 85 percent of said maximum combustion bowl diameter.

A galleryless piston for an internal combustion engine, comprising:

• a monolithic galleryless piston body extending along a central longitudinal axis along which said piston reciprocates in a cylinder bore of an internal combustion engine, said piston body having an upper wall forming an upper combustion surface with an annular ring belt region depending from said upper combustion surface for receipt of at least one piston ring;
• a pair of skirt portions depending from said ring belt region to facilitate guiding the piston within a cylinder bore and having a pair of pin bosses providing a pair of laterally spaced pin bores aligned along a pin bore axis for receipt of a wrist pin;
• said upper combustion surface having first and second portions, said first portion extending annularly along an outer periphery of said upper wall and said second portion forming a combustion bowl depending radially inwardly from said first portion;
• said upper wall having an undercrown surface formed on an underside of said combustion bowl directly opposite said second portion of said upper combustion surface, wherein a pair of pockets extend radially outwardly from said pin bosses along said pin bore axis to said ring belt region, said pockets defining at least a portion of said undercrown surface, a portion of an underside of said first portion and a portion of an inner surface of said annular ring belt region, said pockets having a complete openly exposed projected total 3-dimensional surface area between 45-85 percent of an area defined by a maximum outer diameter of said piston body.