Questions

Question 1

What is the purpose of dynamic dampers?

Answer 1

Reduce vibration

Question 2

What type of bearings are found in a reciprocating engines?

Answer 2

Plain, ball and roller bearings

Question 3

Are the connecting rods used in each cylinder the same of a radial engine the same? Explain.

Answer 3

No, it has master and articulating rods

Question 4

Name the different types of piston rings.

Answer 4

Compression, oil control, oil scraper

Question 5

Where should piston rings gaps be installed relative to each other? Why?

Answer 5

Compression rings gaps should be installed staggered to prevent excessive blowby

Question 6

What could result from incorrectly installed pistons rings?

Answer 6

Excessive oil consumption

Question 7

What purpose do oil control rings serve?

Answer 7

Controls layer of oil on cylinder walls

Question 8

What is used to prevent valve surge or floating in an aircraft engine?

Answer 8

Two or more springs on each valve

Question 9

On engine equipped with hydraulic valve lifters, what should the running valve clearance be ?

Answer 9

Zero

Question 10

What is the purpose of valve overlap?

Answer 10

Better volumetric efficiency and lower cylinder operating temps

Question 11

What is the main advantage of horizontally opposed engines over a radial engine ?

Answer 11

Smaller frontal area and less drag

Question 12

How many throws are in the crankshaft of a six cylinder horizontally opposed engine

Answer 12

6

Question 13

What material are piston rings made of

Answer 13

Cast iron or chrome plated steel

Question 14

What is the reason for using hydraulic lifters in an aircraft engine?

Answer 14

To eliminate valve clearances during operation and reduce component wear

Question 15

What speed does camshaft turn relative to crankshaft speed?

Answer 15

Half the speed

Question 16

What kind of main bearings are used in a horizontally opposed engine?

Answer 16

Steel backed, lead-alloy inserts

Question 17

What stroke is the piston of a recip engine on when the intake begins to open?

Answer 17

Exhaust

Question 18

What stroke is the piston of a recip engine when exhaust valve begins to open?

Answer 18

Power

Question 19

Why are hot and cold valve clearances given for radial engines?

Answer 19

Because of the expansion of the large engine

Question 20

What is a cam-ground piston?

Answer 20

Piston made out of round that expands to be round at operang temperatures

Question 21

Where is the piston when ignition occurs?

Answer 21

Typically, around 30 degrees before top dead center on the compression stroke

Question 22

Describe the inspection you would give the valve springs during engine overhaul.

Answer 22

They should be cleaned thoroughly, then visually inspected for evidence of overheating, cracks,
broken ends, and compression strength

Question 23

What is the purpose of using valves with sodium filled stems?

Answer 23

Sodium
is used because it is an excellent heat conductor.

Question 24

What causes engine sudden stoppage

Answer 24

Striking an object or engine seizure due to intemal damage.

Question 25

What type of inspection must be made after sudden stoppage of an engine?

Answer 25

Most manufacturers require a
complete engine tear down and inspection.