... endurance, High erosion endurance, High concussion endurance. intake & exhaust valve. High attrition endurance, High temperature endurance, High erosion endurance ... normal, good material: INLET VALVE IS SUH3(4Cr9Si2) ; EXHAUST VALVE IS SUH35(21-4N), normal material: INLET VALVE IS ... SUH1(40Cr) ; EXHAUST VALVE IS SUH3(4Cr9Si2). 3. our engine valves are suitable ...