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Bore refers to the diameter of each cylinder.

It acts as a seal against combustion gases and lubricant infiltration into the combustion chamber. Also, its purpose is to transfer heat from the piston to the liner. In the case of a new cylinder block, there can be a few variances in the cylinder bore diameter. Typically, there are three standard-sized cylinder bore diameters. A bore size code is stamped into the top of the cylinder block for each respective cylinder.

  •  A bore pitch is referred to as the distance in between the centerline bore to the centerline of the next cylinder bore adjacent to it in an internal combustion engine. It is also referred to as the mean cylinder width, bore spacing.
  • It is always larger than the inside diameter of the cylinder since it includes the thickness of both cylinder walls and any water passage separating them.

Bore-Stroke Ratio

A Bore -Stroke Ratio is defined as the ratio between the engine cylinder bore diameter to its piston stroke dimension. It determines the engine power and torque characteristics