Process characteristics:In-line, four-cylinder, with dry cylinder liner. The core wall thickness of the water jacket of the cylinder block is relatively thin (4mm locally), and the sand core is easy to deform, which can easily cause instability in the wall thickness of the cylinder bore. During the casting process, the water jacket core is equipped with parallel core heads at the cylinder top to enhance rigidity. Additionally, an integral core assembly process is adopted, where the water jacket core and tappet core are assembled onto the main core assembly before dip-coating, followed by integral dip-coating, to ensure the positional accuracy of the sand core and thus guarantee the wall thickness of the cylinder bore.