Flashcards on Reciprocating Aircraft Engine Fundamentals

Reciprocating Aircraft Engine Fundamentals: A Student Guide

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How are conventional reciprocating engines classified by cylinder arrangement and cooling method?

By cylinder arrangement relative to the crankshaft (in-line, V-type, radial, opposed) and by cooling method (liquid-cooled or air-cooled).

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Aircraft Reciprocating Engines

12 cards

Card 1

Question: How are conventional reciprocating engines classified by cylinder arrangement and cooling method?

Answer: By cylinder arrangement relative to the crankshaft (in-line, V-type, radial, opposed) and by cooling method (liquid-cooled or air-cooled).

Card 2

Question: What is the main advantage of a horizontally opposed engine over a radial engine for modern aircraft?

Answer: A much smaller frontal area and easier streamlining than a radial engine.

Card 3

Question: Why is valve clearance adjusted on radial engines but not on most horizontally opposed engines?

Answer: Most horizontally opposed engines have hydraulic valve lifters that remove clearance; radial engines have solid lifters requiring manual valve clearan

Card 4

Question: What types of piston rings are used in reciprocating aircraft engines?

Answer: Compression rings, oil control rings, and scraper rings.

Card 5

Question: What is the purpose of the oil control rings?

Answer: To control the thickness of the oil film on the cylinder walls.

Card 6

Question: What may result from installing piston rings incorrectly?

Answer: Excessive oil consumption.

Card 7

Question: What type of connecting rod assembly is commonly found in radial engines?

Answer: A master and articulating rod assembly.

Card 8

Question: Why are hydraulic valve lifters used in aircraft engines?

Answer: They keep all clearance out of the valve operating mechanism, decreasing wear of valve train components.

Card 9

Question: At what speed does the camshaft turn relative to the crankshaft in a horizontally opposed engine?

Answer: The camshaft turns at one half of the crankshaft speed.

Card 10

Question: Where is the piston when the ignition spark occurs in a reciprocating engine?

Answer: About 30 degrees of crankshaft rotation before the piston reaches top center on the compression stroke.