A galleryless piston for an internal combustion engine and method of construction thereof are provided. The piston has a monolithic piston body extending along a central longitudinal axis. The piston body has an upper wall forming an upper combustion surface with first and second portions, with the first portion extending annularly along an outer periphery of the upper wall and the second portion forming a combustion bowl. The upper wall has an undercrown surface on an underside of the combustion bowl directly opposite the second portion of the upper combustion surface. The undercrown surface has an openly exposed 2-dimensional surface area, as viewed looking along the central longitudinal axis, between about 35-60 percent of an area defined by a maximum outer diameter of the piston body, thereby providing an expansive area against which oil being splashed or sprayed can freely contact to cool the piston.