Questions Flashcards
What is the purpose of dynamic dampers?
Reduce vibration
What type of bearings are found in a reciprocating engines?
Plain, ball and roller bearings
Are the connecting rods used in each cylinder the same of a radial engine the same? Explain.
No, it has master and articulating rods
Name the different types of piston rings.
Compression, oil control, oil scraper
Where should piston rings gaps be installed relative to each other? Why?
Compression rings gaps should be installed staggered to prevent excessive blowby
What could result from incorrectly installed pistons rings?
Excessive oil consumption
What purpose do oil control rings serve?
Controls layer of oil on cylinder walls
What is used to prevent valve surge or floating in an aircraft engine?
Two or more springs on each valve
On engine equipped with hydraulic valve lifters, what should the running valve clearance be ?
Zero
What is the purpose of valve overlap?
Better volumetric efficiency and lower cylinder operating temps
What is the main advantage of horizontally opposed engines over a radial engine ?
Smaller frontal area and less drag
How many throws are in the crankshaft of a six cylinder horizontally opposed engine
6
What material are piston rings made of
Cast iron or chrome plated steel
What is the reason for using hydraulic lifters in an aircraft engine?
To eliminate valve clearances during operation and reduce component wear
What speed does camshaft turn relative to crankshaft speed?
Half the speed
What kind of main bearings are used in a horizontally opposed engine?
Steel backed, lead-alloy inserts
What stroke is the piston of a recip engine on when the intake begins to open?
Exhaust
What stroke is the piston of a recip engine when exhaust valve begins to open?
Power
Why are hot and cold valve clearances given for radial engines?
Because of the expansion of the large engine
What is a cam-ground piston?
Piston made out of round that expands to be round at operang temperatures
Where is the piston when ignition occurs?
Typically, around 30 degrees before top dead center on the compression stroke
Describe the inspection you would give the valve springs during engine overhaul.
They should be cleaned thoroughly, then visually inspected for evidence of overheating, cracks,
broken ends, and compression strength
What is the purpose of using valves with sodium filled stems?
Sodium
is used because it is an excellent heat conductor.
What causes engine sudden stoppage
Striking an object or engine seizure due to intemal damage.
What type of inspection must be made after sudden stoppage of an engine?
Most manufacturers require a
complete engine tear down and inspection.
