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WorksheetsDiesel engine knowledge check
Total questions: 40
Worksheet time: 33mins
What does this component do?
Nothing - it is not part of an engine
Actuate the valves to fill air and vent exhaust to the cylinder
Translate reciprocating motion from the piston to rotary motion
Meter and inject fuel to control combustion
Diesel engine combustion is the process of combusting _______________ to create an expanding gas that makes the engine operate.
water and oil
air and water
fuel
fuel and air
The flywheel is a heavy weight attached to the crankshaft that
controls the timing to open and close the intake and exhaust valves.
stores and releases rotational energy during the intake, compression, and exhaust strokes.
is super fly and shaped like a pizza.
stores and releases rotational energy to start the engine.
Each movement of the piston in and out of the cylinder is called a
compression.
exhaust.
stroke.
shift.
What is the correct order of the 4 strokes of an internal combustion engine?
Compression, Intake, Exhaust, Power
Power, Compression, Intake, Exhaust
Intake, Power, Compression, Exhaust
Intake, Compression, Power, Exhaust
Engine revolutions per minute (RPM) measure the rotations of what component?
Camshaft
Crankshaft
Starter
Connecting rods
What is the minimum number of cylinders required for a 4 stroke engine to ensure no interruptions in output power?
(ie. at least one cylinder in power stroke)
5
3
1
4
A 4 stroke, 4 cylinder engine is running at 1000 RPM. How many power strokes (ignitions) occur during 1 minute?
2000
1000
500
4000
The diameter of the engine cylinder is called the ______ and the distance the piston can move is called the ________. The multiplication of these 2 factors provides the engine __________.
bore, stroke, displacement
displacement, stroke, bore
bore, cam ratio, displacement
cat, dog, unicorn
The compression ratio is calculated by measuring the difference in the ______________ when the piston is in the lowest and highest positions. A ___________ compression ratio results in a more efficient engine.
displacement, lower
bore size, higher
bore size, lower
displacement, higher
Fuel injection permits higher compression ratios because
the cylinder size is variable.
air can be compressed before fuel is added.
the stroke can be extended.
fuel is mixed with air before compression.
Diesel engines offer better fuel economy and more power under heavy loads than gasoline engines because the _____________ can be changed to fit the load.
fuel to air ratio
oil to fuel ratio
air flow
air to core ratio
High torque and extra power at lower engine speed is a condition called _________ and is a unique advantage to diesel engines.
knocking
lugging
overspeed
beast mode
What does a fuel injector do?
inject..... fuel?
set and control fuel pressure to the rail
control the timing and the atomization (spray) of fuel delivery into the cylinder
control fuel flow from the tank, through the filters, to the engine
Diesel engines operate within set speed limits. The bottom limit is called ____________ and the upper limit is called _____________.
bottom speed, top speed
low speed, high speed
low limit, high limit
low idle, high idle
Engine speed will drop as more power is needed. To produce more power and raise engine speed again, more fuel must be supplied. This control system function is done automatically by a ______________.
governor
fuel valve
fuel pump
fuel injector
Why is fuel filtration important to diesel engine operation?
Fuel can mix with oil and must be separated by a filter.
Dirty fuel can plug and damage the fuel injectors. Plugged injectors will not deliver the correct amount of fuel.
The fuel contains too much oil as delivered.
Fuel filters are not important. Diesel fuel will burn the same way regardless of contamination.
Why does a Caterpillar diesel engine require a cooling system?
Cylinder combustion temperatures are really high (fuel is exploding!).
The sun can make the engine very hot on a hot day.
Engines do not need cooling system. Air circulation cooling is sufficient.
Fuel will spontaneously combust if the engine is not cooled.
The water pump on an engine is designed to
keep water out of the fuel injectors.
keep water out of the oil system.
purify water and make it available to both the operator and the engine.
circulate water through the cooling system.
The radiator is designed to
transfer heat from the engine coolant to the air around the fins.
transfer hear from the engine oil to the air around the fins.
transfer heat from the fuel to the air around the fins.
control the emissions of the engine exhaust.
What does the thermostat do in the engine cooling system?
prevent the engine from overheating at extreme temperatures.
control the flow of oil through the engine.
prevent the radiator from over-cooling the engine when the engine is cold.
control the flow of air through the engine at low temperatures.
The boiling point of the coolant can be raised if the cooling system is ___________.
open
filled
pressurized
flowing
Engine coolant is also used in what other system on Tier IV Final Caterpillar engines?
Fuel system to cool the injectors
Hydraulic system to cool the valves
Aftertreatment system to cool the diesel particulate filter
Aftertreatment system to heat the diesel exhaust fluid tank in cold weather
Which NPI data hub dashboards are most useful to cooling system design and validation engineers? (choose all that apply)
Histograms
Fluid Temps
Starting
Amb Temp & Alt
What does this component hold?
Fuel
Coolant
Diesel Exhaust Fluid
Oil
List the major functions of the engine oil system (choose all that apply)
Lubrication
Fueling
Cleaning
Cooling
The volume and depth of the engine oil pan determine the __________ of the engine.
tilt capability
power performance
lugability
cold weather performance
Engine oil helps ________ the engine by carrying away __________ that is captured by the ____________ before the oil is recirculated.
cool, heat, filter
cool, heat, tank
clean, unburnt fuel particles, tank
clean, metal wear particles, filter
Cracks in the engine oil cooler can result in
fuel mixing with air, damaging the engine due to high volumes of fuel.
fuel injector failure due to fuel dilution.
coolant mixing with engine oil, increasing the oil volume and diluting the oil's lubricity.
oil mixing with air, increasing the oil volume and diluting the oil's lubricity.
Why are oil sampling and analysis services (S.O.S.) important to extending engine component life?
Not all engines wear at the same rate. Operating conditions determine true wear and periodic sampling helps customers track oil life and replace when needed.
All engines wear at a similar rate. Operating conditions do not affect engine wear and engine oil should be changed as directed by the maintenance manual.
Caterpillar branded oil wears at the same rate and does not need to be sampled. Customers using 3rd party oil should periodically sample to ensure 3rd party oil meets life targets.
NOx sensors measure
sulfur dioxide.
nickel tetraoxide.
calcium carbonate.
nitrogen oxides.
What is this component called? What does it pressurize?
Fuel pump, fuel
Water pump, water
Air intake valve, air
Turbocharger, air
What does an aftercooler do?
Cools the fuel to distribute combustion.
Cools the water system before coolant flows back to the engine.
Cools the air so more air can be packed into the same space in the cylinder.
Cools the air to set the correct temperature for engine combustion to burn fuel more efficiently.
The intake air compressor of a turbocharger is turned by what component?
the timing gears
the exhaust turbine
the water pump flow
the crankshaft
Turbochargers spin _________ in _________ altitude conditions (like Colorado) because the air is ___________. ____________ can damage the turbocharger bearings.
slower, higher, thinner, Underspeed
faster, higher, thinner, Overspeed
the same rate, higher, the same, Temperature
faster, lower, thinner, Overspeed
The ___________ captures _____________ and the ____________ reduces ______________, both of which are regulated by Tier 4 final emissions regulations.
turbocharger, air, fuel filter, contamination
SCR, particulate matter, DPF, NOx
DPF, particulate matter, SCR, NOx
muffler, particulate matter, DPF, NOx
What would an engineer who designs passive regeneration systems want to monitor from field and lab data? (choose all that apply)
exhaust temperature
exhaust back pressure
oil pressure
DPF inlet temperature
Why does the diesel exhaust fluid (DEF) tank have a heater?
DEF temperature is critical to the catalytic reduction reaction
Cold DEF is not as effective at reducing NOx levels
DEF is a mixture of oil and urea and will become too viscous at cold temperatures
DEF is a mixture of water and urea and will freeze at cold temperatures
Why is an engine inducement particularly painful for customers?
The engine reduces power if the emissions system is not functioning properly.
The engine will seize and fail if the inducement is not addressed quickly.
The engine does not notify the customer of the condition and can damage the components.
The government will shutdown the engine and fine the customer and manufacturer if the inducement is not addressed.
Select all the categories that cause engine inducements. (Choose all that apply)
Low DEF level
EGR system fault
Dosing system interruption
Low intake air pressure
