It takes two revolutions of the crankshaft to complete each four-stroke cycle.
This image depicts the power stroke, which is the third stroke in the four-stroke cycle. The power stroke generates the engine’s power.
The connecting rod is what links the crankshaft to the piston and helps provide rotary motion, and therefore, power.
A 12:1 ratio of air to fuel would be a rich mixture, fast-burning and possibly producing black smoke.
Diesel engines operate with a high compression ratio. The compression ratio for a diesel engine can range anywhere from 16:1 to 22:1.
Antifreeze raises the boiling point of your coolant, thereby rendering it much more efficient at transferring heat.
This is a spark plug. Spark plugs are threaded into the cylinder head, where they protrude into the combustion chamber and generate the spark to initiate combustion.
Of the items given, only the powertrain control module is in charge of firing and regulating electronic fuel injectors.
The combustion chamber, indicated in the diagram by the number 2, is where the actual combustion of the air-fuel mixture takes place. It is located in the cylinder head directly above the piston (1 in the diagram).
As the “brain” of the car, it is the job of the PCM to gather signals from the car’s sensors and generate outputs to control the vehicle’s functions. The diagnostic data link, choice (B), connects a scan tool to the PCM; the scan tool, (D), is what technicians use to read the PCM.
The oil galleries are drilled directly through the crank shaft in order to provide pressurized oil to the connecting rod bearings. The pistons, push rods, and valves do not receive pressurized oil from the crank shaft oil galleries, so (A), (B), and (C) are incorrect.
The shock absorber provides damping to the suspension system. The damping effect converts motion energy into heat, which is then dissipated though the shock absorber body into the atmosphere. The shock absorber does not generate electrical power or potential energy, or neutralize chemical energy. Therefore, choices (A), (B), and (D) are incorrect.
The radiator is the engine component designed to reject heat in a water-cooled engine. The other answer choices are incorrect because antifreeze is a subcomponent of the coolant, the water pump circulates the coolant, and the thermostat regulates the coolant temperature.
Throttle body fuel injectors are located in the throttle body, so (A) is incorrect. Direct injection fuel injectors are located in the combustion chamber, so (B) is incorrect. The flame front is the burning portion of the fuel air mixture in the combustion chamber, so (D) is incorrect. Multiport fuel injectors are located in the intake manifold, so (C) is correct.
The function of the catalytic converter is to further reduce unburned hydrocarbon fuel in the exhaust gas by decomposing the unburned hydrocarbon fuel in the exhaust gas into carbon dioxide, water vapor, and heat. As a result, high heat is developed in the catalytic converter. Answer choices (A), (C), and (D) are incorrect because they represent components not developed in the catalytic converter.
Coil-on-plug ignition systems eliminate the need for spark plug wires because the ignition coil is mounted directly over the spark plugs. Answer choices (A), (C), and (D) are still necessary components in a coil-on-plug ignition system, and therefore are not correct.
The alternator converts mechanical energy into electrical energy needed to operate the vehicle's systems and to charge the battery as required. Power charger, (A), is a generic term, not a specific component. The battery, (B), stores electrical energy and the rectifier, (C), converts alternating current from the alternator to direct current.
A torque converter converts the rotational power of the engine to fluid power. A half-shaft, (A), connects the transaxle to the drive wheels in a front wheel drive vehicle. The drive axle, (C), sends power from the differential to the drive wheels. Constant-velocity joints, (D), are located between the transaxle and front drive wheels.
Rack and pinion gears convert rotational motion from the steering wheel to the linear motion needed to change the direction of the wheels. This type of gear arrangement is not used in any of the other systems listed.
If brake fluid were compressible, the fluid displacement created by the master cylinder would be diminished at the individual brake piston assemblies and braking power would be severely diminished. Viscosity, (A), refers to how easily a fluid flows. While this could have some effect on brake performance, it is not the most important property. Acidity, (C), is irrelevant to transmitting pressure and fluid movement. Adaptability, (D), is not a relevant property.
Proper lubrication of internal moving parts is essential to long engine life. Excessive wear on internal engine parts can occur when the engine oil becomes dirty or experiences degradation of its lubricating properties. Internal combustion engines are lubricated by circulating oil internally, not by lubricating fittings, (A). Changing automatic transmission fluid, (B), does not need to be done frequently and is important to the life of the transmission more than the engine. Thermostats, (D), generally don't require maintenance; if they fail to function properly they are usually replaced.
Look back over your work on the practice questions. If you got some questions wrong, think about why.