Cylinder bore having variable coating

An engine block, comprising:

• a body including a bore wall and a sprayed coating overlying the bore wall having a thickness and pores dispersed within the thickness;
• the sprayed coating including a first depth region disposed adjacent an interface of the sprayed coating with the bore wall and a second depth region disposed adjacent an exposed surface of the sprayed coating, the second depth region having a greater average porosity than the first depth region, the sprayed coating further includes a third depth region disposed between the first and second depth regions within the coating thickness, and the third depth region having an average porosity between that of the first and second depth regions.

An engine block, comprising:

• a body including a bore wall and an iron or steel coating overlying the bore wall having a thickness and pores dispersed within the thickness;
• the iron or steel coating including a first depth region disposed adjacent an interface of the iron or steel coating with the bore wall and a second depth region disposed adjacent an exposed surface of the iron or steel coating, the second depth region having a greater average porosity than the first depth region, the iron or steel coating further includes a third depth region disposed between the first and second depth regions within the coating thickness, and the third depth region having an average porosity between that of the first and second depth regions.