A method of treating the surface of an aluminum-based engine block cylinder bore that has been mechanically roughened. In one form, this method includes using vibratory stress relief, elevated temperature stress relief or cryogenic stress relief so that residual stresses imparted to the surface by the roughening process are reduced. In this way, a protective coating that is also applied to the bore surface will exhibit better adhesion and lower incidence of stress-induced or fatigue-induced cracking.

In a spark ignition engine, a thermal insulation thin layer is formed over a wall surface, facing an inside of a combustion chamber, of a base material forming the combustion chamber, and for a thermal conductivity [W/(m.Math.K)], a thermal diffusivity [mm.sup.2/s], and a thickness L [m] of the thermal insulation thin layer, L16.7 and L207.4().sup.0.5 are satisfied. With such a configuration, a heat loss Q_total escaping from gas in a cylinder to the wall of the combustion chamber over all strokes can be reduced, and the thermal efficiency can be improved without inducing degradation of knocking due to an increase in an amount of heating Q_intake of the gas in the cylinder during an intake stroke.

Remanufacturing a used cylinder liner includes receiving a used cylinder liner having a fillet relieved of residual compressive stress via service in an engine, and compressing a material substrate of the cylinder liner forming a fatigue sensitive fillet, such that a non-uniform profile of the fillet is reshaped via plastic deformation of the material substrate. Residual compressive stress is restored to the fillet at least in part via the plastic deformation. A mask and used cylinder liner assembly for processing the used cylinder liner during remanufacturing is also disclosed.

An engine block for a vehicle includes a bore surface defining a cylinder bore. The bore surface exhibits a first microstructure and includes a pattern of a plurality of cycloidal features formed in the bore surface. The plurality of cycloidal features each exhibit a first length in a first axis and a second length in a second axis arranged 90 degrees from the first axis. The plurality of cycloidal features also exhibit a ratio of the first length to the second length in a range of 1:1.5 to 1.5:1. The plurality of cycloidal features further exhibit a second microstructure including tempered martensite, wherein the second microstructure is different from the first microstructure. The engine block is included in a vehicle. The cycloidal features are formed with a laser.

The present invention refers to a cylinder liner for an internal combustion engine, comprising a flange having a seat-engaging surface which is configured for bearing onto a flange seat of an engine block, and wherein the seat-engaging surface has a sloped portion which extends along at least a half of a radial length of the seat-engaging surface and which is inclined relative to a radial plane being normal to a longitudinal axis of the cylinder liner.