A) CHECK FOR EXHAUST VALVE SPINDLE ROTATION:-
THIS CHECK IS CARRIED OUT WHEN ENGINE WAS RUNNING. FIRST PULL UP THE INDICATOR ROD PLACED AT THE TOP OF THE EXHAUST VALVE AND TURN IT TO 90 DEGREE AND LET IT REST ON AIR PISTON.
AS THE AIR PISTON MOVES THE INDICATOR WILL FOLLOW ITS MOVEMENT. DURING ROTATION OF THE VALVE SPINDLE, THE TOP POSITION OF THE INDICATOR WILL CHANGE ABOUT 6 MM, BECAUSE OF THE GROOVE IN THE PISTON.
B) SPINDLE DROP-DOWN TIME CHECK:-
THIS TEST IS CARRIED OUT WHEN ENGINE IS STOPPED
- ENGAGE ALL THE ROTATION INDICATOR ON THE EXHAUST VALVES.4
- SHUT OFF AND RELEASE THE SPRING AIR ON THE VALVE, NEXT TO THE ENGINE-SIDE MANEUVERING STAND.
- CHECK THE SPINDLE DROP TIME FOR ALL THE VALVES:
- DROP TIME WITIN 30 MINUTES : CHECK AND OVERHAUL THE VALVE AND CHECK FOR AIR SPRING TIGHTNESS.
- DROP TIME FROM 30 MINUTES TO 1 HOUR : KEEP UNDER OBSERVATION.
- DROP TEST ABOVE 1 HOUR : OK