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POWERPLANT ORALS
CHAPTER 1 - RECIPROCATING ENGINES
Question | Answer |
---|---|
WHAT IS THE PURPOSE OF DYNAMIC DAMPERS ON CRANKSHAFTS? | THEY REDUCE ENGINE VIBRATION. |
WHAT TYPES OF BEARINGS ARE GENERALLY FOUND IN RECIPROCATING ENGINES? | PLAIN, BALL AND ROLLER BEARINGS. |
ARE THE CONNECTING RODS USED IN EACH CYCLINDER OF A RADIAL ENGINE THE SAME? EXPLAIN. | NO. RADIAL ENGINES USE MASTER AND ARTICULATING ROD ASSEMBLIES. |
NAME THE DIFFERENT TYPES OF PISTON RINGS. | OIL CONTROL, COMPRESSION, AND OIL SCRAPER. |
WHERE SHOULD PISTON RING GAPS BE INSTALLED RELATIVE TO EACH OTHER, AND WHY? | COMPRESSION RING GAPS SHOULD BE STAGGERED SO THAT THEY DO NOT ALIGN. THIS PREVENTS EXCESSIVE BLOW-BY. |
WHAT COULD RESULT FROM INCORRECTLY INSTALLED PISTON RINGS? | EXCESSIVE OIL CONSUMPTION . |
WHAT PURPOSE DO OIL CONTROL RINGS SERVE? | THEY REGULATE THE THICKNESS OF THE OIL FILM ON THE CYLINDER WALLS. |
WHAT IS USED TO HELP PREVENT VALVE SURGE OR FLOATING IN AN AIRCRAFT ENGINE? | TWO OR MORE SPRINGS ARE USED ON EACH VALVE. |
ON ENGINES EQUIPPED WITH HYDRAULIC VALVE LIFTERS, WHAT SHOULD THE RUNNING VALVE CLEARANCE BE? | ZERO. |
WHAT IS THE PURPOSE OF VALVE OVERLAP? | IT ALLOWS BETTER VOLUMETRIC EFFICIENCY AND LOWERS CYLINDER OPERATING TEMPERATURES. BETTER SCAVAGING OF THE EXHAUST GASSES. |