Systems and methods for a cylinder bore coating fill material

A method, comprising:

• forming a coating on an inner surface of a cylinder bore, the coating including a plurality of surface pores;
• applying a mask to the coating;
• applying a fill material to at least one unmasked region of the coating;
• removing the mask after applying the fill material;
• finishing the inner surface to reveal the coating in the at least one unmasked region, the finishing including maintaining the fill material in surface pores of the plurality of surface pores within the at least one unmasked region.

A cylinder for an engine, comprising:

• a cylinder bore;
• and
• a piston configured to reciprocate within the cylinder bore, the cylinder bore including:
• an inner surface including an upper region configured to circumferentially surround the piston when the piston is at top dead center, a lower region configured to circumferentially surround the piston when the piston is at bottom dead center, and a middle region positioned between the upper region and the lower region;
• a coating on the inner surface, the coating having a plurality of surface pores;
• and
• fill material filling only surface pores of the plurality of surface pores in the upper region and/or lower region and not filling surface pores of the middle region.