Reciprocating Engines Flashcards
What is the purpose of dynamic dampers on crankshaft
Reduce engine vibration
What types of bearings are generally found in reciprocating engines
Plain, Roller, Ball bearings
Are the connecting rods used in each cylinder of a radial engine the same
NO… Radial engines use master and articulating rod assemblies
Name the different types of piston rings
Oil control, Compression and oil Scrapper
Where should piston rings 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 of 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
When troubleshooting a running engine malfunction, what does a cold cylinder indicate
No combustion in that cylinder
Name at least one part of an inspection that should be made after a propeller strike (not sudden stoppage)
(1)Inspect the engine mounts, cranckcase, and nose section for damage
(2)Inspect the oil screens/filters for metal particles
(3) Inspect the propeller drive or crankshaft for misalignment.
What is the fuel pressure range on Float-Type carburators
3 to 5 PSI
What publication is used to check an engine for normal operation
The manufacturer’s maintenance manual
What should be done to repair a loose stud in an engine crankcase
Remove the loose stud, inspect the hole for size and condition of the threads. It may be necessary to use a suitable oversize stud or HeliCoil insert
What is an indication that a primer is leaking or is open
during engine operation
The engine will not idle properly
What procedure should be followed when valve blow-by is indicated by a hissing sound on a reciprocating engine when pulling the propeller through
Perform a cylinder compression test to identify the faulty cylinder
What factors about the condition of an engine can be learned by studying the results of a compression test
The results of a compression test determine if the valves, pistons rings and pistons are adequately sealing
What is meant when it is said that an engine PART is within “serviceable limits”
A part that is within the manufacture’s serviceable limits and can be used in an engine, will not likely wear to the point
of causing engine failure within the next time between overhaul TBO interval
When an engine is overhauled, how is its total time affected? When an engine is rebuilt, how is its operating history affected
OVERHAULED - The total time on the engine must be continued and the time since major overhaul is entered into the logbook.
REBUILT - If the manufacturer rebuilds the engine it is granted a ZERO-TIME status and is considered to have NO
previous operating history
Name some of the precautions that should be performed prior engine replacement
Disconnect the battery, turn off the fuel valves, chock the wheels and if necessary install a tail stand
When inspecting a piston, where are cracks most likely to be found
Highly stressed areas, base of piston bosses, inside at the junction of the bore and the walls and ring lands
How is a cylinder barrel inspected for out of roundness
You must measure with a (cylinder bore gauge or a telescopic gauge and
micrometer,or an inside micrometer) the top of the cylinder and the skirt.
This two readings should be taken, 90° to each other
Is the aircraft electrical system required to power a cylinder head temperature gauge
NO… A thermocouple is used as the electrical source
What are the possible indications of an oil pressure transmitter or indicator malfunction
A severe or sudden drop in oil pressure while the oil temperature remains normal and the oil supply remains full
What are some indications of induction system leakage
Low power and uneven running
