Patent ID: 6129133
Filing Date: 2000-10-10
Classification: B22D,F02F

Abstract:
A method for manufacturing a cast cylinder block having multiple cylindrical openings in side-by-side relationship in at least one plane containing the axes of said cylindrical openings, said openings extending from a crankcase region to a cylinder block top deck, the method comprising the steps of:forming in a core box a frangible isolator core having a thickness corresponding to the distance from one end of said cylindrical openings at said crankcase region to a location on said cylindrical openings approximately midway between said one end and said top deck, the length of said isolator core being approximately equal to the total span of said multiple cylindrical openings, the width of said isolator core being greater than the diameters of said cylindrical openings;said step of forming said isolator core including forming cylindrical openings in said isolator core corresponding to said multiple cylindrical openings;placing said isolator core in a casting mold package assembly;introducing molten metal into said casting mold package assembly whereby said multiple cylindrical openings are cast in said cylinder block with an isolator cavity surrounding said multiple cylindrical openings and with an outer engine block wall surrounding said isolator cavity;said isolator cavity being isolated from said crankcase region.