Method of engine cylinder bore enlargement

摘要

A method is provided for forming enlarged cylinder bores in an engine based on a family of internal combustion engines having an original cylinder bore axis for each bore, wherein each cylinder bore is constrained against enlargement toward one side. The method includes providing an offset axis parallel to the original cylinder bore axis and spaced toward an opposite side of the cylinder bore by a dimension equal to one half of a predetermined bore diameter enlargement, and centering the enlarged cylinder bore on the offset axis. The method preserves a minimum wall thickness from the cylinders to camshaft bores between the cylinder banks while the outward enlargement dimension is preferably limited to a value which does not require changing the cylinder head bolt pattern or reduce the wall thickness below minimum values in other portions of the cylinders.