Process characteristics:in-line, six-cylinder, with wet cylinder liner. The camshaft chamber on the bottom box surface of the cylinder block is of a fully enclosed structure, and the inner chamber has high requirements for cleanliness. The cover box structure is complex and is prone to pore defects. Therefore, in the casting process, the bottom plate core is used to assemble the waterway core, camshaft core and tappet core into a whole for dip-coating, to reduce flashing. In order to prevent the occurrence of air holes in the cover box, the pouring system is designed with the concept of large flow rate and low flow velocity after simulation analysis, and a large overflow is designed at the top of the cover box cylinder.