IC engine cylinder bores are finished in best way by:

Explanation:

​Honing

• Honing is an abrading process mostly used for polishing bored and reamed holes and external cylindrical surfaces using bonded abrasive stones (called hones)
• Honing is, in fact, a cutting operation and is used to remove material less than 0.25 mm but sometimes it is used to remove stock up to 3 mm also
• The honing is mainly used to correct some out of roundness, taper, and tool marks left by previous operation or axial distortions
• Honing is done by means of bonded abrasive grit sticks (of aluminium oxide or silicon carbide) applied to the surface to be honed under controlled pressure and with a combination of rotary and reciprocating motions of abrasives
• Most honing is done on an internal cylindrical surface, such as automobile cylindrical walls.

Lapping

• It is an abrading process for refining surface finish and the geometrical accuracy of flat cylindrical and spherical surfaces.
• It is a process or removing surface roughness, tool marks, surface cracks from grinding, slight distortions and other minor – defects from previous operations
• Lapping produces geometrically true surfaces, corrects minor surface imperfections, improves dimensional accuracy and provides a very close fit between two contact surfaces

Grinding

• It is a metal cutting operation performed by means of a rotating abrasive tool, called “grinding wheel”.
• Grinding is the most common form of abrasive machining.
• It is a material cutting process which engages an abrasive tool whose cutting elements are grains of abrasive material known as grit.
• These grits are characterized by sharp cutting points, high hot hardness, chemical stability, and wear resistance.
• The grits are held together by a suitable bonding material to give the shape of an abrasive tool.