Recip Engines Bottom Half

Question 1

What are the major components on the bottom end?

Answer 1

-Connecting rods
-Crankshaft
-Crankcase
-Camshaft and lifters
-accessory pads and drives

Question 2

How are the body of the connecting rod and cap identified?

Answer 2

They will have the cylinder no. on them

Question 3

How are connecting rods held in place?

Answer 3

Two bearing inserts are installed in the big end and held in place by tangs on the inserts

Question 4

What do connecting rods do?

Answer 4

They carry the forces produced by the pistons into the crankshaft

Question 5

What is critical about connecting rods?

Answer 5

The torque on the nuts of the connecting rod bolts

Question 6

How do you determine the stroke of the engine?

Answer 6

The length of the crankshaft throw
2xcrank cheek = stroke

Question 7

What is the purpose of sludge plugs?

Answer 7

Any sludge in oil is going to be trapped and held by he sludge plugs until the next overhaul

Question 8

What is the function of dynamic dampers in the crankshaft?

Answer 8

The floating counterweights absorb torsional vibrations by changing the resonant frequency

Question 9

What are the types of propeller attachments?

Answer 9

Tapered-small low powered engines
Splined-larger high powered engines
Flanged-most common

Question 10

What is the purpose of a bearing?

Answer 10

To permit the other surface to move with a minimum of friction and wear

Question 11

What are the three types of bearings used?

Answer 11

Plain
Ball
Roller

Question 12

What are the three types of bearing loads?

Answer 12

Thrust
Radial
Combination

Question 13

What types of bearings are on the crankcase?

Answer 13

plain bearings

Question 14

What are the crankcase halves sealed with?

Answer 14

A thin gasket compound and a fine silk thread to provide an efficient oil seal

Question 15

What is the valve operating mechanism also referred to as?

Answer 15

The valve train

Question 16

What closes the valve?

Answer 16

Spring pressure

Question 17

What are valve lifters also called?

Answer 17

Tappets

Question 18

What is the function of a hydraulic valve lifter?

Answer 18

It automatically maintains zero clearance using oil pressure int the valve train unlike solid lifters

Question 19

What is the purpose of the small hole on the pushrod?

Answer 19

To allow oil to pass through them to lubricate the rocker arm assembly

Question 20

What is TBO?

Answer 20

Time between overhaul-the recommended max no. of hours that an engine can run between overhauls without endangering safe normal operation

Question 21

What is the reliability of a part?

Answer 21

The ability of a component to perform and maintain its functions in routine conditions, as well as hostile or unexpected conditions

Question 22

What were most common recip engine configurations?

Answer 22

-In line
-V-engine
-Radial engines
-Horizontally opposed engines

Question 23

Pro’s of a horizontally opposed engine

Answer 23

-The operate at higher RPM
-Require a shorter prop
-Better visibility in front of the aircraft

Question 24

What is the difference between TCM and Lycoming engine numbering?

Answer 24

-TCM cylinder 1 is the right rear cylinder
-Lycoming cylinder 1 is the right front cylinder

Question 25

What is the function of lubrication systems?

Answer 25

Reduces internal friction, cushions the impact, removes heat

Question 26

What are the two basic types of lubrication systems?

Answer 26

Wet sump
Dry sump

Question 27

What does a crankshaft do?

Answer 27

With the help of the connecting rods transforms the back and forth movement of the pistons into rotary motion.

Question 28

How are the crankshaft bearings and connecting rod bearing journals hardened?

Answer 28

By nitriding

Question 29

What is crankcase?

Answer 29

The foundation of the engine and attaches the engine to the airframe

Question 30

What is a bearing?

Answer 30

Is any surface which supports, or is supported by, another surface

Question 31

What is a thrust load?

Answer 31

Are exerted on the bearing on a plane parallel to the center of the shaft (also called axial loads)

Question 32

What is a radial load?

Answer 32

Are exerted on the bearing on a plane perpendicular to the shaft

Question 33

Where are plain bearings used?

Answer 33

Crankshaft, camshaft, connecting rods, and accessory drive shafts

Mostly subjected to radial loads

Question 34

Where are ball bearings used?

Answer 34

Some supercharger impeller shaft bearings and rocker arm bearings

Question 35

Where are roller bearings used?

Answer 35

Straight roller bearings used where the bearing is subjected to radial loads only

Tapered roller bearings used where bearing is subjected to both radial and thrust loads

Question 36

What is the crankcase breather line?

Answer 36

Prevents the pressure inside the crankcase from becoming excessive