WorksheetsEngines - how they work
Total questions: 55
Worksheet time: 28mins
Every engine converts heat into mechanical enery
true
false
Every engine converts up and down piton motion into circular motion at the crankshaft
True
False
Compressed air has a higher temperature than the air we breathe
True
False
One cubic foot of uncompressed air can be compressed into one cubic inch of space or less
True
False
Liquid or solid fuel burns faster than vaporized fuel
True
False
The rotary engine turns reciprocating motion into circular motion
True
False
The stroke of the piston is set by the "throw" of the crankshaft (how far it is offset)
True
False
The modern gasoline engine works best at a 15 to 1 compression ratio
True
False
Gasoline engines work best at a one-part fuel and two-part air mix.
True
False
In a two-stroke engine there are actually four movements of the piston, two up and two down, in one complete cycle.
True
False
In a diesel engine, air alone is compressed in the cylinder
True
False
The power stroke in the reciprocating engine begins when the piston almost reaches the top of the stroke and the fuel-air mix is ignited.
True
False
Two-stroke cycle engines create about 50% power gain over a four-stroke engine of the same displacement.
True
False
The carburetor on a diesel engine mixes air and atomized fuel before it is injected into the intake manifold
True
False
A typical six-cylinder diesel engine has a total of twelve fuel injectors at the cylinders
True
False
A diesel injection pump times, measures, and delivers fuel under pressure to the cylinders
True
False
Water is one of the major contaminates of diesel fuel.
True
False
Carburetors control the engine speed.
True
False
A key to keeping an engine running efficiently, is to make sure the crankcase is tightly sealed and working as a partial vacuum
True
False
Modern engines sometimes are designed so that crankcase vapors are routed back to the intake system to help reduce air pollution.
True
False
Cooling system parts must be matched in capacity in order to provide adequate heat rejection
True
False
Diesel engines use heat heat plugs instead of spark plugs to ignite the fuel-air intake mix
True
False
Diesels must be built sturdier than gas engines to withstand greater forces of combustion.
True
False
Fuel energy is measured in British Thermal Units (BTU's).
True
False
Gasoline has more BTU's than diesel fuel.
True
False
A non-structural engine should never be used to replace a structural engine.
True
False
Matter, such as diesel fuel, can be changed, but it can not be destroyed.
True
False
Inertia is the push or pull that starts, stops, or changes the direction of a moving body.
True
False
The turning effect of force is called torque.
True
False
Work is being done when a car engine is running and the gearshift is in neutral.
True
False
Indicated horsepower is the most useful unit of measurement used to determine the efficiency of an engine in a vehicle.
True
False
A "Prony brake" or dynamometer is used to measure the gas pressure that is developed inside the combustion chamber of a cylinder.
True
False
Never exceed the rated horsepower of an engine.
True
False
It is better to run leaner fuel-air mixes in a gasoline engine than one that is to rich.
True
False
Heat is the greatest source of energy loss in an engine.
True
False
When air is compressed in a cylinder it si
Ignited
Heated
Vaporized
Stabilized
A fuel is vaporized in order to
Heat it throughly before ignition
Transport it easily to combustion of the cylinder.
Help each particle contact enough oxygen to ignite fully.
Eliminate water vapor in the fuel.
At the bottom a piston stroke cylinder chamber holds 80 cu. In. of air. At the top of a stroke it holds 10 cu. In. of air. What is the compressed ratio?
8 to1
3 to 8
8 to 3
1 to 8
In a two-stroke diesel engine, the complete cycle is
Power stroke, exhaust, intake, fuel injection, compression.
Intake and exhaust, compression, fuel injection, power stroke
Intake, power stroke, exhaust, fuel injection, compression
In a typical four-stroke cycle engine having six cylinders, the cranks on the crankshaft are set how far apart?
90 degrees
45 degrees
120 degrees
180 degrees
Turbochargers in an intake system are usually used to help
Transport the fuel-air mix to the combustion camber
Exhaust gases from the exhaust manifold.
Swirl the fuel-air mix at the injector nozzles.
Increase horsepower.
The function of a diesel fuel injection nozzle is to
Mix the fuel with the air and inject it into the cylinder
Filter the diesel fur=el and separate impurities before combustion.
compress the air-fuel mix.
Atomize the fuel and spray it into the cylinder combustion chamber.
Exhaust systems help to
Reduce noise, put pressure on the exhaust valves, and exhaust waste gases.
Exhaust the cylinder, exhaust the exhaust manifold, and muffle noise.
Lubrication in an engine lubrication system
Helps conserve energy by reducing heat through friction reduction.
Helps deaden the noise of the engine.
Seals the moving parts of the cylinder.
All of the above
Air cooling systems are usually used for engines that are designed into what kind of machines?
Off-the-road equipment such as bulldozers that work in harsh environments.
Outboard marine engines.
Push-type lawnmowers.
All of the above.
Governing systems on an engine
Match the power to the load.
keep the speed at a steady level.
Both A and B
In an in-line type of engine, the cylinders are arranged in
A straight line above the crankshaft.
In two opposed lines opposite each other across the crankshaft.
inline eith the overhead valve camshaft.
None of the above
Engine types can be classified by
Grade of metal used in their construction.
Valve arrangement, and type of fuel.
Cubic inch displacement.
Manufacturer's trade name
What is the typical compression ratio for a gasoline engine?
8 TO 1
16 TO 1
15 TO 1
1 TO 1
The law of inertia best applies to which machine function?
Piston movement
Heat dissipation
Flywheel movement.
Combustion of fuels.
One horsepower is equal to
The amount of heat it takes to raise the temperature of one gallon of water 599 fegrees Fahrenheit.
One thousand turns of a crankshaft
The lifting of a weight 550 pounds one foot in one second.
Horsepower measured in combustion chamber of the engine is called
Rated horsepower
Flywheel horsepower
Friction Horsepower.
indicated horsepower
Volumetric efficiency in an engine is determined by
Dividing brake horsepower by indicated horsepower and multiplying by 100
Dividing the amount of air taken in by the pistion displacement and multiplying by 1oo.
Measuring the amount of exhaust and dividing it by the theoretical gassification of the fuel and multyplying by 100.
Dividing the theoretical BTU displacement of the fuel with actual heat output and multiplying by 100.
Compression ratios in a cylinder should not be altered to produce more horsepower because of posssible damage to
Cylinder and cylinder walls
The carburetor
The crankshaft
Lubrication quality
Boyle's and Charles' Law of Thermodynamics deals with
The effect of torsion on the crankcase.
The loss of energy at the components driven by the engine.
The potential nuclear energy light and matter
The reaction of gases in the cylinder combustion chamber
