Abstract: A system for hydrostatically testing a cylinder block for an internal combustion engine simulates the gas loads imposed upon the cylinder block when the engine is firing. The system includes an engine cylinder block having multiple cylinders, with pressure conduits extending from a series of hydraulic control valves to each of the operating cylinders such that hydraulic fluid is conducted into the engine cylinders at pressures and frequencies which approximate, if not exceed, the magnitude and frequency of the gas pressure loading imposed upon the operating cylinders when the engine is firing.

Abstract: A main bearing structure for an internal combustion engine includes a cylinder block with main bearing bulkheads which are bored for receiving cylindrical alignment elements carried in a main bearing cap assembly. The cylindrical alignment elements and the bores formed in the cylinder block are not concentric, with the result that a majority of the cylindrical alignment elements extending into the cylinder block are in interference fit with the cylinder block itself.