Reciprocating Engines

Question 1

What is the purpose of a dynamic damper on crankshafts?

Answer 1

Reduce engine vibration.

Question 2

What types of bearings are generally found in reciprocating engines?

Answer 2

Plain, ball, roller.

Question 3

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

Answer 3

No, radial engines use master and articulating rod assemblies.

Question 4

Name the different types of piston rings.

Answer 4

Oil control, compression, oil scraper.

Question 5

Where should piston ring gaps be installed relative to each other and why?

Answer 5

Staggered so they do not align, prevents excessive blow by.

Question 6

What could result from incorrectly installing piston rings?

Answer 6

Excessive oil consumption.

Question 7

What purpose do oil control rings serve?

Answer 7

Regulate the thickness of the oil film on the cylinder walls.

Question 8

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

Answer 8

Two or more springs used on each valve.

Question 9

What should the running valve clearance be?

Answer 9

Zero.

Question 10

What is the purpose of valve overlap?

Answer 10

Better volumetric efficiency, lower cylinder operating temperatures.