If you look at the entire molding machine process layout, the small end riser is not the best choice here. According to the equilibrium solidification theory, the riser neck should not be placed directly on the large flat surface, because it is easy to cause the E-shaped heat knot, thereby increasing the heat knot at the riser neck of the casting, which is likely to cause shrinkage defects at the joint between the casting and the riser neck. Generally speaking, if there is a sinking, it is often insufficient to fill the metal liquid. It is necessary to increase the riser and the neck of the neck to increase the inflow of molten metal. The shrinkage hole at the neck of the riser indicates that the neck of the riser is too large, and it is necessary to reduce the neck of the riser. Therefore, it is contradictory to increase and decrease the riser neck. Since the molding machine process arrangement does not allow for large movements, the position of the small end riser is not allowed to change. According to the equilibrium solidification theory, the riser neck should have enough area to fill the molten iron and make up the shrinkage, while the riser neck can not exacerbate the hot section of the casting. Therefore, the riser neck was changed to a flat shape, the area was increased to 9 cm, and the riser neck was moved outward by 20 mm. The overall consideration is to increase the area of ​​the riser neck to facilitate the shrinkage while minimizing the thermal impact of the riser on the casting. In addition, the pouring temperature is adjusted to 1360-1380 degrees according to the wall thickness of the casting. With this improvement, shrinkage and shrinkage defects are eliminated.