Patent ID: 8104175
Filing Date: 2012-01-31
Classification: F01M,F02F,Y10T

Abstract:
1. A method of manufacturing a cylinder block for a multi-cylinder engine, wherein the cylinder block comprises a crankcase and cylinder bores disposed therein separated by cylinder walls, wherein the crankcase is adapted to receive a crankshaft and comprises crank chambers disposed therein separated by partition walls, wherein each of the crank chambers of the crankcase corresponds to one of the cylinder bores of the cylinder block, wherein a cylinder bore side of each partition wall comprises a honing runoff portion thinner in section than a crankshaft side thereof such that a step face results in each partition wall, the method comprising: forming a runoff groove extending in a direction of the crankshaft in the step face of at least one of the partition walls of the crank chambers; and after the runoff groove is formed, forming a communication hole to enable communication between crank chambers at least partially within the runoff groove in the at least one of the partition walls so as to extend from an end of the runoff groove in the direction of the crankshaft as far as the honing runoff portion.