LX470 — NEW FEATURES 12 4. Engine Proper Cylinder Head A lead-free valve seat is used for environmental purposes. The air injection port is provided for the air injection system. For details, see page 37. IN Air Injection Port EX 030LX30C Cylinder Block A lead-free crankshaft bearing is used for environmental purposes. Four oil jets for each piston are added. A check valve is built into an oil jet to stop oil injection when engine oil pressure is low, preventing engine oil pressure drop. Check Valve Oil Jet Check Valve Opening Pressure: 2.1 to 2.5 kgf/cm 2 , (210 to 250 kPa) 030LX31C