Reciprocating engines

Question 1

If the ignition swath is moved from both to either left or right during an engine ground check,normal operation is usually indicated by a slight?

Answer 1

Drop in torque meter pressure indication

Question 2

What engine does this statement go with “The intake valve closes on the compression stroke”

Answer 2

A four stroke cycle aircraft engine

Question 3

What is the best indication of worn valve guides?

Answer 3

High oil consumption

Question 4

Which condition would be the least likely to be caused by failed or failing engine bearings?

Answer 4

Low oil temperatures

Question 5

To reduce the power output of an engine equipped with a constant speed propeller and operating near maximum BMEP, the

Answer 5

Manifold pressure is reduced with the throttle control before the RPM is reduced with the propeller control

Question 6

(1)Preignition is caused by improper ignition timing
(2) Detonation occurs when an area of the combustion chamber becomes incandescent and ignites the air fuel mixture in advance of normal timed ignition.
What describes theses statements?

Answer 6

Neither 1 or 2 is true

Question 7

Which of the following would indicate a general weak-engine condition when operated with a fixed-pitch propeller or test club

Answer 7

Lower than normal static RPM full throttle operation

Question 8

What does vale overlap promoter

Answer 8

Better scavenging and cooling characterstics

Question 9

By use of a differential pressure compression tester it is determined the cylinder 3 of a nine-cylinder radial engine will not hold pressure after the crankshaft has been rotated 260 degrees from top dead center compression stroke cylinder 1. How can this indications usually be interpreted

Answer 9

A normal indication

Question 10

One of the best indicators of reciprocating engine combustion chamber problems is

Answer 10

Spark plug condition

Question 11

Which of the following is a characteristic of a thrust bearing used in most radial engines

Answer 11

Deep-groove ball

Question 12

(1) Cast iron piston rings may be used in chrome-plated cylinders.
(2) Chrome-plated rings may be used in plain steel cylinders.
What is the best explanation for these statements

Answer 12

Both 1 and 2 are true

Question 13

The volume of a cylinder equals 70 cubic inches when the piston is at bottom center. When the piston is at the top of the cylinder the volume equals 10 cubic inches what is the compression ratio?

Answer 13

7:1

Question 14

There is less rolling friction when ball bearings are used than when roller bearing are employed is true regauging bearing used in what?

Answer 14

High-powered reciprocating aircraft engines

Question 15

Excessive valve clearance will casue the duration of valve opening to

Answer 15

Decrease for both intake and exhaust valeves

Question 16

The valve clearance of an engine using hydraulic lifters,when the lifters are completely flat or empty should not exceed?

Answer 16

A specified amount above zero

Question 17

If the oil pressure gauge fluctuates over a wide range from xero to normal operating pressure, the most likely cause is?

Answer 17

Low oil supply

Question 18

Engine operating flexibility is the ability of the engine to

Answer 18

run smoothly and give the desired performance at all speeds

Question 19

If air-fule ratio is proper and ignition timing is correct the combustion process should be completed

Answer 19

Judt after top center at the beginning of the power stroke

Question 20

If the hot clearance is used to set the valves when the engine is cold what will occur during operations of the engine

Answer 20

The valves will open late and close early

Question 21

The five events of a four-stroke cycle engine in the order of their occurrence are

Answer 21

Intake,compression, ignition,power,and exhaust

Question 22

After spark plugs from an opposed engine have been serviced in what position should they be reinstalled.

Answer 22

Next in firing order to the one from which they were removed and swapped bottom to top

Question 23

Which of the following is most likely to occur if an overhead valve engine is operated with inadequate valve clearances

Answer 23

The valves will not seat positively during start and engine warmup

Question 24

An engine misses in both the right and left positions of the magneto switch.The quickest method for locating the trouble is to

Answer 24

Check for one or more cold cylinders

Question 25

Which type of bearing are generally used for connecting rods and camshafts?

Answer 25

Plain

Question 26

Which of the following would most likely cause a reciprocating engine to backfire through the induction system at low RPM operations

Answer 26

Lean Mixture

Question 27

What could cause excessive pressure buildup in the crankcase of a reciprocating engine

Answer 27

Plugged crankcase breather

Question 28

Which air-fuel mixture will result in the highest engine temperature

Answer 28

A mixture leaner than a manual lean mixture of .060

Question 29

Excessive valve clearance in a piston engine

Answer 29

Decreases valve overlap

Question 30

What is the principal advantage of using propeller reduction gears?

Answer 30

To enable the engine RPM to be increased with an accompanying increased in power and allow the propeller to remain at a lower more efficient RPM

Question 31

How may it be determined that a reciprocating engine with a dry sump is pre-oiled sufficiently?

Answer 31

Oil will flow from the engine return line or indicator port

Question 32

The floating control thermostat used on some reciprocating engine installations helps regulate oil temperature by

Answer 32

COntrolling air flow through the oil cooler

Question 33

What special procedure must be followed when adjusting the valves of and engine equipped with a floating cam ring?

Answer 33

Eliminate cam bearing clearance when making valve adjustment

Question 34

Excessive valve clearance results in the valves opening

Answer 34

late and closing early

Question 35

If an engine with a stroke of 6 inches is operated at 2,000 PRM the piston movement within the cylinder will be

Answer 35

at maximum velocity 90 degrees after TDC

Question 36

A nine-cylinder engine with a bore of 5.5 inches and a stroke of 6 inches will have a total piston displacement of

Answer 36

1,283 cubic inches

Question 37

Cam-ground pistons are installed in some aircraft engines to

Answer 37

provide a better fit at operating temperatures

Question 38

Increased water vapor (higher relative humidity) in the incoming air to a reciprocating engine will normally result in which of the following.

Answer 38

Decreased engine power at a constant RPM and manifold pressure

Question 39

The operating temperature valve clearance of a radial engine as compared to cold valve clearance

Answer 39

greater

Question 40

Full-floating piston pins are those which allow motion between the pin and

Answer 40

both the piston and the small end of the connecting rod

Question 41

Grinding the valves of a reciptocatingenfine to a feather edge is likely to result in

Answer 41

preignition and burned valves

Question 42

Some aircraft engine manufacture’s equip their product with chocked or taper-ground cylinders in order to

Answer 42

provide a straight cylinder bore at operating temperatures

Question 43

During overhaul of an engine a first step of inspection on a crankshaft should be to

Answer 43

perform a runout check

Question 44

The actual power delivered to the propeller of an aircraft engine is called

Answer 44

brake horsepower