Process characteristics: in-line, six-cylinder structure. The self-hardening sand on-line production process is adopted for on-line core assembling, core setting and pouring. Castings are poured by horizontal pouring process. The pouring system is designed according to the design concept of large flow rate and low flow velocity. The overflow exhaust structure is added on the top surface to effectively ensure the controllable defect rate of pores and sand holes in castings.