Question 1

Intake stroke

Accepted Answer

Piston moves downward, drawing air-fuel mixture into the cylinder.

Question 2

Compression stroke

Accepted Answer

Piston moves upward, compressing the air-fuel mixture.

Question 3

Power stroke

Accepted Answer

Spark plug ignites the compressed air-fuel mixture, creating combustion and generating power.

Question 4

Exhaust stroke

Accepted Answer

Piston moves upward, pushing out the exhaust gases from the cylinder.

Question 5

Valve overlap

Accepted Answer

Period when both the intake and exhaust valves are open simultaneously.

Question 6

Valve timing

Accepted Answer

Timing of the opening and closing of the intake and exhaust valves.

Question 7

Ignition timing

Accepted Answer

Timing of the spark plug firing in relation to piston position.

Question 8

Spark advance

Accepted Answer

Adjusting the timing of the spark plug firing.

Question 9

Knock

Accepted Answer

Uncontrolled combustion, resulting in a knocking sound and potential engine damage.

Question 10

Air-fuel ratio

Accepted Answer

Proportion of air to fuel in the mixture.

Question 11

Carburetor

Accepted Answer

Device that blends air and fuel for combustion in the engine.

Question 12

Fuel injection

Accepted Answer

Directly injecting fuel into the combustion chamber.

Question 13

Throttle body

Accepted Answer

Controls the amount of air entering the engine.

Question 14

Manifold absolute pressure (MAP) sensor

Accepted Answer

Measures intake manifold pressure.

Question 15

Engine control module (ECM)

Accepted Answer

Controls various engine functions based on sensor inputs.

Question 16

Mass airflow (MAF) sensor

Accepted Answer

Measures the amount of air entering the engine.

Question 17

Oxygen sensor (O2 sensor)

Accepted Answer

Measures oxygen content in the exhaust gases.

Question 18

Ignition coil

Accepted Answer

Converts low-voltage battery power into high-voltage spark.

Question 19

Distributor

Accepted Answer

Distributes high-voltage spark to each spark plug.

Question 20

Ignition system

Accepted Answer

Components responsible for generating and delivering spark to the combustion chamber.

Question 21

Camshaft

Accepted Answer

Controls the opening and closing of the valves.

Question 22

Crankshaft

Accepted Answer

Converts reciprocating motion into rotational motion.

Question 23

Timing chain

Accepted Answer

Transfers power from the crankshaft to the camshaft.

Question 24

Cooling system

Accepted Answer

Regulates engine temperature and prevents overheating.

Question 25

Thermostat

Accepted Answer

Regulates coolant flow to maintain optimal engine temperature.

Question 26

Radiator

Accepted Answer

Cools the coolant by transferring heat to the surrounding air.

Question 27

Water pump

Accepted Answer

Circulates coolant throughout the cooling system.

Question 28

Fan clutch

Accepted Answer

Engages and disengages the radiator fan based on engine temperature.

Question 29

Cylinder head

Accepted Answer

Houses the combustion chambers, valves, and spark plugs.

Question 30

Piston

Accepted Answer

Moves up and down within the cylinder, transferring force from combustion to the crankshaft.

Question 31

Connecting rod

Accepted Answer

Connects the piston to the crankshaft.

Question 32

Engine block

Accepted Answer

Main structural component of the engine, housing cylinders and other internal parts.

Question 33

Valve clearance

Accepted Answer

Gap between the valve stem and rocker arm or camshaft.

Question 34

Valve lift

Accepted Answer

Maximum distance the valve opens during its operation.

Question 35

Valve spring

Accepted Answer

Provides the necessary force to close the valves.

Question 36

Valve seat

Accepted Answer

The surface against which the valve rests to seal the combustion chamber.

Question 37

Valve guide

Accepted Answer

Guides the valve's movement within the cylinder head.

Question 38

Valve stem seal

Accepted Answer

Prevents oil from entering the combustion chamber through the valve stem.

Question 39

Cylinder leakage test

Accepted Answer

Determines the efficiency of the cylinder's compression.

Question 40

Compression ratio

Accepted Answer

Ratio of cylinder volume at bottom dead center to top dead center.

Question 41

Crankcase ventilation system

Accepted Answer

Prevents pressure buildup in the crankcase.

Question 42

Positive crankcase ventilation (PCV) valve

Accepted Answer

Controls the flow of gases from the crankcase to the intake manifold.

Question 43

Exhaust gas recirculation (EGR) system

Accepted Answer

Reduces nitrogen oxide (NOx) emissions.

Question 44

EGR valve

Accepted Answer

Recirculates a portion of the exhaust gases back into the intake manifold.

ASE Medium-Heavy Truck Certification Flashcards: T1 - Gasoline Engines