Design of gating system for die casting aluminum alloy cylinder block with cast-iron cylinder liner free was conducted.The cylinder block with uneven thickness has the characteristics of complicated shape and various structure.Meanwhile

pre-inserted cylinder liners are canceled

leading to a thicker wall-thickness.Single-side feeding is beneficial for the exhausting during pouring process

avoiding the occurrence of shrinkage holes（porosity）through exhausting gas in cylinder.Vacuum drawing can decrease gas hole greatly and densify the microstructure to improve the mechanical properties of the cylinder block.Cylinder insert mechanism was designed effectively

and its surface was treated to decrease frictional coefficient

which could decrease the harm to the mould during pull-out.