Engine Principles Practice Test

These questions are part of the practice quiz. Start practicing

• If nickel is detected in the lube oil, which subsystem should be inspected for potential failure?
• Who is the inventor of the 'Fireball' type pre-combustion chamber?
• The lightest, strongest, and quietest engine blocks are:
• Which statement best describes how temperature affects oil viscosity?
• Maximum lubrication oil temperature should not exceed which value?
• Which value is NOT a cylinder bank spacing for a V-configured engine?
• Connecting rod cap mounting bolts are manufactured from metal alloys of grade ________ or higher.
• Which of the following is the purpose of frost plugs or core plugs used in engine blocks?
• What is the minimum allowable engine oil pressure at idle?
• Which of the following is a common corrective action for a cylinder misfire?
• Air to fuel ratios can exceed __________ when idling a diesel engine, promoting excessive cylinder component wear.
• What is the primary role of a catalytic converter in emissions control?
• The shortest duration stroke of a four-stroke diesel engine is the _________ stroke.
• What is catalyst light-off and why is it important for emissions during warm-up?
• Intake manifold resonance influences engine performance by
• Pilot injections reduce combustion noise by:
• Which crankshaft hardening method yields the deepest penetration of hardened material?
• Why is engine warm-up important?
• Which component converts the reciprocating motion of our engines into rotational movement?
• What is the purpose of a catalytic converter and how does it reduce emissions?
• A cylinder liner absent of crosshatch is called?
• Which tool would a technician utilize to verify piston to cylinder wall clearance?
• A by-product of combining oxygen and hydrocarbons during combustion is?
• What percentage of fuel savings can be obtained by adopting a lubricating oil windage tray?
• When measuring piston diameter for wear, the reading is taken at what orientation relative to the piston pin bore?
• Which device uses exhaust energy to compress intake air?
• Which statement best describes the high-pressure fuel system used in the DI chamber?
• Specific power is defined as
• Which government agency tests engine oil additives?
• A stoichiometric air-fuel mixture provides nearly complete combustion; O2 sensors optimize fuel delivery around this ratio for balanced performance and emissions.
• How many societies and organizations have developed standards focused on reciprocating internal combustion engines?
• What is the correct difference between indicated horsepower (IHP) and brake horsepower (BHP)?
• The two-cycle diesel engine delivers a power stroke every __________ of crankshaft rotation.
• What piston design is most commonly used today?
• Which emission control technique lowers combustion temperatures to reduce NOx?
• Excessive engine exhaust heat is detrimental to engine components, which operating condition would a technician expect to see high exhaust temperatures?
• Choose the component that is NOT considered a cylinder component.
• It only takes a ________ second delay to produce excessive cylinder pressure.
• Which statement about oil viscosity is true?
• Pilot injections normally occur ________ degrees before the main injection.
• How many gaskets are utilized to properly seal a filter of the cartridge design?
• Which lubricating oil is the most expensive to purchase?
• A dual-mass flywheel is typically used in which type of vehicle?
• What is a primary advantage of lean burn in engines?
• V8 engines have cylinder banks arranged at which angle to allow for even crankshaft rotation between firing impulses?
• The clearance volume is measured with the piston at the TDC position, which factor listed below would be directly affected by changing the physical clearance volume dimension?
• Which of the following is the most likely cause of excessively high oil pressure?
• Which percentage increase in tensile strength do CGI blocks offer over traditional cast iron blocks?
• What causes blow-by and what indicators might you observe in the crankcase?
• Which component forms the main housing for cylinders and mounts the crankshaft?
• Diesel engines operate with which type of air-fuel mixture and ignition method?
• Which option lists the correct flame temperature for diesel fuel?
• Where would a technician draw an oil sample for analysis?
• As a general rule of thumb, there should be between 0.003 and ________ thousands of an inch clearance between a piston and the cylinder wall.
• Define compression ratio and describe its effect on efficiency and knock risk.
• What is "dynamic compression ratio" and how does it differ from static compression ratio?
• The piston ring that scrapes excess lube oil from the cylinder wall during the downward stroke is called the...
• What are piston rings and what happens when ring lands fail?
• Which sensor detects engine knock and helps protect the engine?
• Which material yields the lightest, strongest, and quietest engine blocks?
• During break-in, applying a heavy load serves primarily to promote what?
• Connecting rod cap mounting bolts are manufactured from metal alloys of grade ______ or higher.
• Which component forms the border between itself and the engine block to form the combustion chamber?
• What is the most common heat source presently used to start combustion in a diesel engine?
• Which system is responsible for removing excess heat from the engine air intake system and heating the vehicle cab compartment?
• You are to purchase a high torque rise engine; which application would the high torque rise engine be best suited for?
• The lubricating system performs how many distinct functions?
• What are early signs of insufficient lubrication in an engine and typical causes?
• The flame temperature of diesel during combustion is about 4,000 degrees Fahrenheit. True or False?
• How many degrees of crankshaft rotation would be required for a single piston to travel from bottom dead center to top dead center?
• The flame temperature of diesel fuel during combustion is reported to be approximately:
• How fast does a twin balance shaft assembly rotate compared to the engine's rotation speed?
• What is knock sensing and how is it used in modern engines?
• How does turbocharging affect volumetric efficiency and the engine's power band?
• When breaking in a newly rebuilt engine, how long should the technician apply a heavy load to promote the piston ring to wall sealing?
• Which of the following is the most recent diesel engine oil classification?
• Measuring the piston diameter for wear, a technician will record the reading ________ degrees opposite of the piston pin bore.
• Which lubricating oil additive is critical for use in hydraulically controlled fuel injectors?
• Direct injection engines require fuel injectors capable of delivering much higher injection pressures to better atomize fuel for combustion. True or False?
• Pilot injections reduce combustion noise by shortening ignition delay.
• The lubricating oil most expensive to purchase is typically:
• Which statement best describes the difference between direct fuel injection and port fuel injection regarding combustion control?
• Flame temperature of diesel fuel can exceed over ____________.
• Which component forms the combustion chamber boundary with the engine block?
• Synthetic lubricants reduce oil consumption by what percentage?
• The "15W" in 15W-40 engine oil stands for which of the following?
• What is the difference between detonation and pre-ignition?
• Which statement best defines volumetric efficiency and its influencing factors?
• Which block design uses what is called a serpentine block wall near the crankcase area?
• Which piston ring scrapes excess lube oil from the cylinder wall during its downward stroke?
• The operator of an on-highway tractor depresses the throttle to increase engine speed; how must the fuel system governor react to meet the operator's request?
• How is torque measured in the metric system?
• Exhaust Gas Recirculation (EGR) lowers NOx formation by which primary mechanism?
• What property of engine oil primarily determines the strength of the lubricating film between moving parts?
• Engines with a rear mounted gear-train have minimal gear rattle due to close proximity of the __________.
• Which cooling method removes heat from bearings and other moving parts via engine oil flow?
• Explain the function of an EGR valve and the impact of EGR on engine performance during idling.
• Compression ratios beyond ___________ generally will result in a decrease of engine efficiency.
• Peak torque output is usually obtained ____________ rpm above idle.
• Which failure would NOT cause liquid to collect on top of a piston?
• High torque rise engines for highway trucks are typically which type of engines?
• Valve overlap refers to which phenomenon in cam timing?
• The latest Compacted Graphite Iron engine blocks boost of a __________ increase in tensile strength over traditional cast iron engine blocks.
• In a two-stroke diesel engine, a power stroke occurs every how many crankshaft degrees?
• What is a lean burn strategy and what are its advantages and challenges?
• What is the difference between a wet sump and a dry sump lubrication system?
• Which term describes a long stroke relative to bore?
• Which combustion chamber design utilizes a high-pressure electronically controlled fuel system?
• A properly designed combustion chamber will provide good fuel economy for which type of emissions?
• The cooling effect of scavenging air in a two-stroke engine accounts for what percentage of engine cooling?
• Piston-to-wall clearance is typically between 0.003 and how many thousandths of an inch?
• Which component re-ingests exhaust gases to reduce NOx emissions?
• How many functions does a lubricating system perform?
• Peak torque is typically achieved at about how many rpm above idle?
• What is the effect of cooler intake air on engine performance?
• Which piston design features a nickel insert within the crown?
• Which statement is true regarding idle operation and air-to-fuel ratio based on the given material?
• Which piston ring hardening process was adopted when EGR was introduced?
• Which percentage range is associated with fuel savings from a lubricating oil windage tray?
• Which diesel engine design has the highest reported thermal efficiency?
• Which measuring tool would a technician use to verify the main bearing to crankshaft running clearance?
• Which block design feature is intended to improve rigidity by extending material around the crankcase?
• Differentiate between a blower, a supercharger, and a turbocharger.
• Today's modern diesel engines have a thermal efficiency of ____________ .
• What is the term for the maximum safe spark advance before knocking occurs and how do engines protect against exceeding it?
• Which statement best describes a cylinder liner that lacks a crosshatch pattern on its inner surface?
• What percentage of friction is associated with the engine's piston?
• Which fuel delivery method provides more precise metering at high engine loads?
• Higher compression ratios improve efficiency but increase knock risk and require what type of fuel?
• During which stroke of a four-cycle engine would a liquid-filled cylinder stop the crankshaft from rotating?
• Which of the following could cause liquid to collect on top of a piston?
• A small ignition delay can lead to which consequence in the engine?
• Diesel engines differ from Otto cycle engines in terms of ignition method, compression ratio, and typical fuel-air mixture. Which statement is correct?
• Which agency tests engine oil additives?
• Which range best describes the thermal efficiency of modern diesel engines?
• Scavenging in an engine context refers to:
• In response to a higher engine speed request, the governor typically advances what aspect of fuel delivery?
• In a four-stroke engine, how many crankshaft revolutions constitute one engine cycle?
• Brake Mean Effective Pressure (BMEP) is used to compare engine performance. Which statement best describes BMEP?
• Which series of engine oils is used in diesel engines?
• Combustion requires a fuel source and _________________, which is the required element to support combustion?
• Which vehicle type would utilize a dual-mass flywheel?
• Synthetic lubricants claim a 2% to ___ reduction in fuel consumption.
• In an engine design with interference between valves and pistons, what component ensures correct timing to avoid contact?
• Which option is NOT a major source of frictional losses in an internal combustion engine?
• If a diesel fuel requires more than __________, the engine may not start or run.
• In spark-ignition engines, which description correctly differentiates knock from pre-ignition?
• Intercooling serves what purpose in turbocharged engines?
• Diesel engine oils are commonly referred to as which series?
• What is the role of the oxygen sensor in a modern gasoline engine?
• Most combustion slobber is produced during:
• The most likely cause of cavitation on a replaceable cylinder liner is
• Which statement about fuel injection placement is accurate?
• What is the function of a crankshaft position sensor and how does it interact with the engine control unit?
• In 15W-40 engine oil, the '15W' indicates viscosity at what temperature?
• Which engine block design has the cylinder and cylinder block as one cast component?
• A CI engine relies on __________ to generate heat for combustion.
• How many gears are incorporated within a scissor gear arrangement?
• In a diesel engine, which factor should determine when to change engine oil?
• A condition known as ___________ lock can bend a connecting rod.
• A high nickel content detected within the lube oil; which engine component could be breaking down to produce this nickel?
• Which component is the largest structure of an engine?
• Identify the largest structural component of an engine.
• CK is the designation for which type of engine oil classification?
• There are four phases of combustion that occur in a DI combustion chamber, choose the incorrect phase listed below.
• Connecting rods are manufactured to withstand forces __________ times greater than those during normal operation.
• What is the purpose of a knock sensor and how does it influence engine control?
• A harmonic wave is known to sound like ___________.
• Idle time is known to be especially destructive to cylinder components.
• If the cooling system thermostat fails closed, what is the most likely engine symptom?
• Which piston design incorporates a nickel insert within the piston crown?
• What is the purpose of the engine coolant radiator and why is airflow important?
• Explain the purpose of Exhaust Gas Recirculation (EGR) and its effect on NOx formation.
• What does the dynamic compression ratio account for that static compression ratio does not?
• Which piston cooling method is the most efficient?
• Variations between individual liner protrusions must be no more than _________ between the highest and lowest liner.
• Which device is mechanically driven by the engine to compress air, often directly by the engine?
• How does ignition timing influence engine torque and efficiency?
• Which best describes the difference between a carburetor and fuel injectors in delivering fuel?
• Which statement best describes the relationship between pilot injections and ignition delay?
• Symptoms of ring land damage include what?
• What is a cooling system thermostat and its function in engine operation?
• Heat is released in the combustion process when hydrogen and carbon bond with oxygen. True or False?
• The ring end gap stagger of a three-ring set should be spaced ______ degrees apart.
• How do water jackets and oil cooling differ in purpose and operation within an engine?
• Due to the high volume of air flow during scavenging in a two stroke engine, the cooling affect of this air is reported to be responsible for ___________ of engine cooling.
• What is the primary function of a turbocharger's wastegate?
• Which component should be removed before the cylinder components?
• For an ideal Otto cycle, the efficiency is η = 1 - 1/r^(γ-1). If the compression ratio r increases while γ remains constant, what happens to the efficiency?
• Describe the function of a lubrication system's oil pressure and viscosity and their impact on engine wear.
• How do changes in intake air temperature impact engine performance and emissions?
• In a three-ring set, the end gaps should be spaced at how many degrees apart?
• Explain the purpose of the camshaft and belt/chain timing in an interference engine.
• What is the stoichiometric air-fuel ratio for gasoline and why is it important for emissions control?
• A common indicator of a cylinder misfire is
• Which unit is used to express torque in the metric system?
• Which additive is indicated as critical for hydraulically controlled fuel injectors?
• How do emissions control systems function together in gasoline engines?
• Which block design is associated with enhanced rigidity around the crankcase?
• Which area of the crankshaft has the most stress applied to it during operation?
• Which component attaches to the bottom of the engine block?
• Which statement best explains why higher injection pressure is important in DI engines?
• Heat is released within the combustion process when _________ and carbon bond with oxygen. Which element bonds with oxygen to release heat?
• A harmonic wave is described as sounding like which of the following?
• Differentiate between forced induction (turbocharger) and naturally aspirated engines in terms of efficiency and operating characteristics.
• Camshaft timing influences valve lift and the engine's breathing. Which description best summarizes its role?
• Which factor would be subtracted from indicated horsepower to obtain brake horsepower?
• Which type of crankshaft hardening technique will result in the deepest amount of hardening?
• Which system is responsible for removing combustion gases from the combustion chamber?
• Cartridge filters are preferred over spin-on filters because:
• Which of the following takes place when engine oil becomes hotter?
• Which piston surface comes in direct contact with the cylinder wall?
• Which of the following is the most likely cause of excessively low oil pressure?
• What does ignition delay refer to in diesel combustion?
• Define octane rating and its relation to engine knock resistance.
• Which component connects an engine's piston to the rotating crankshaft?
• Which design feature describes a cylinder that is formed as part of the same casting as the engine block?
• In a four-stroke engine, how many crankshaft rotations are required to complete one full rotation of the camshaft?
• Brake Specific Fuel Consumption is defined as what, and what does a lower value indicate about engine efficiency?
• Which of the following is the purpose of bolster bolts or tie bolts?
• Higher specific power from a smaller displacement engine typically requires
• Which percentage of piston friction is cited in engine friction discussions?
• Which item is NOT a major source of frictional losses in an internal combustion engine?
• Which of the following statements about cartridge filters is true?
• Which piston design is most commonly used today?