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About This Quiz
Whether you’re a factory-trained, professional auto technician or a shade tree mechanic who likes to tinker with old cars, you have to know an awful lot about engines to maintain and repair them properly. And you really have to know your stuff if you’re into modifying engines for more performance.Â
Well, if you know your wrist pins from your crank pins, this quiz is for you. If you’re the one that friends and relatives call for help every time their cars' engines make funny noises, you ought to breeze through these 35 questions quicker than a Dodge Hemi V8 goes through a gallon of gas.Â
Now, even though piston engines work pretty much the same as they did 100 years ago, much has changed over the decades. Some young car enthusiasts today have never had the satisfaction or frustration of working rebuilding a carburetor or fiddling with a distributor to get the ignition timing just right. Meanwhile, there some “old school†enthusiasts still shake in their shoes at the sight of a fuel injection system or an engine control unit. And then, there are those who can work on any engine ever made and make it sing.Â
Which one are you? Take this quiz and find out!
What is the purpose of a torque wrench?
It tightens bolts to a specific pressure.
A torque wrench is used to tighten bolts to a specific tension setting. A gauge or digital readout on the wrench indicates when correct torque is applied. Using a torque wrench is critical when tightening bolts on engine parts, such as connecting rod bolts, main bearing cap bolts, and cylinder head bolts, among others.
It is used to tighten or loosen "stuck" bolts.
It allows you to remove bolts that are in hard-to-reach places.
It is used to compress springs.
Cars with fuel injection no longer need which device?
Valves
A carburetor
If you’re old enough to remember carburetors in passenger cars, you’ve been driving a long time. While fuel injection had been used on a few cars since the 1950s, the advent of computerized control in the 1980s made it more common. A far more precise method for supplying fuel to the cylinders, fuel injection proved invaluable for increasing power while reducing emissions and improving fuel economy.
A catalytic converter
Fuel filter
What is one difference between gasoline and diesel engines?
The gasoline engine is a two-stroke engine, and the diesel is a four-stroke.
The gasoline engine uses a spark plug, and the diesel uses a glow plug.
Gasoline engines compress the air/fuel mixture, and a spark plug ignites it. In a diesel engine, high compression alone ignites the mixture, but diesel engines also use glow plugs to help start the process on very cold days.
The gasoline engine pistons are arranged in a V-shape, and the diesel cylinders are in a line.
The gasoline engine uses a supercharger, and the diesel can only use a turbocharger.
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Thick white smoke coming out the exhaust usually means what?
The engine is on fire.
The engine is clean.
The cylinder head gasket has failed.
A car leaving a trail of white smoke from the tailpipe is a telltale sign that either the cylinder block has cracked or a head gasket has failed. A cracked block can also leak oil.
The air conditioning system is leaking into the exhaust.
What should you do if your car begins to overheat?
With the car off, you should immediately add more water to the radiator.
Turn on the air conditioner to make it cooler.
Pull off the road and turn off the engine as soon as possible; wait until the engine has cooled down before checking it.
An engine that is overheating can be damaged quickly. After safety pulling off the road, stop the engine and let it cool before opening the hood to check anything. Opening the hood right away can unleash a cloud of scalding hot steam right in your face.
Ignore the problem, and it will go away.
What part opens and closes engine valves?
The piston
The camshaft
A shaft with oblong-shaped lobes, the camshaft operates “followers†that push intake and exhaust valves open at precise intervals. Pressure from valve springs allows the valves to close.
The crankshaft
The axle
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The connecting rod does what?
It connects the engine to the axle.
It connects the piston to the crankshaft.
The connecting rod connects to the piston to the crankshaft, converting the pistons’ vertical motion in the cylinders (as the combustion cycle pushes the piston downward) into rotational motion that turns the crankshaft.
It connects the engine to the transmission.
It connects the piston the camshaft to the valve stems.
Which component did Cadillac introduce so the driver no longer had to turn a crank?
The distributor
The alternator
The crankshaft
The starter motor
Before Cadillac introduced the electric starter in 1912, car owners had to manually crank the engine to initiate the combustion process. It was difficult and dangerous to do, and could even break a person’s arm.
If the engine is overheating, which of the following is a likely reason?
The air conditioning needs Freon.
It is too hot outside.
The oil pump has failed.
The thermostat has malfunctioned.
It’s much less common for a modern car engine to overheat than it was in the past, but when it happens, checking the thermostat (when the engine cools down) is usually the second thing to do after first determining if the radiator or a hose is leaking coolant.
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Which part of the engine do you need a harmonic balancer tool to install and remove properly?
The crankshaft
Before removing a crankshaft from an engine, you use a harmonic balancer remover to remove the harmonic balancer.) Don’t you just love that its name is exactly what it does?) This is the part that connects the crankshaft to the drive belt pulleys and also helps reduce vibration.
The cylinder head
The oil pump
The piston
What is the most likely reason you would notice spark plugs coated in oil when you are changing them?
The crankshaft is leaking.
The engine block has a hole in it.
The valves or piston rings are leaking.
This is more likely to be a problem in an old, worn engine. Oil that leaks past piston rings or valve stems gets makes its way to the combustion chamber and “fouls†the spark plug. The result could be misfiring, or not firing at all.
The camshaft is leaking.
What is the purpose of a fuel injector?
To inject fuel into the oil
To atomize and inject fuel
A fuel injector does just what its name suggests, injecting fuel into the engine to burn. First, it atomizes the fuel, turning it into a fine spray. In many modern car engines, “direct injection†puts the fuel right into the combustion chamber. Other kinds of fuel injection have been used to inject it further upstream, either into the intake manifold or the cylinder ports.
To purify the fuel
To eject used fuel from the combustion chamber
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When the thermostat is hot, what does it do?
It closes.
It turns on the radiator.
It opens.
After you start your car’s engine, its internal temperature will begin to increase as a result of the combustion cycles. When a pre-set temperature is reached, the thermostat opens to allow engine coolant to flow between the engine and radiator. A “stuck†thermostat can cause the engine to overheat.
It turns on the check engine light.
What does DOHC stand for?
Differential Oil Hardware Cylinder
Double Overhead-cam
In an inline four- or six-cylinder engine, “DOHC†means double overhead-cam, which means the engine has two camshafts, one to operate the intake valves, and the other to work the exhaust valves. In a V-type engine, DOHC means two camshafts per cylinder bank for a total of four.
Digital Optimal Horsepower Control
Direct Open Hydraulic Catalyst
In what way can you "tune" the exhaust system to increase engine power?
Moving the muffler closer to the engine
Installing afterburners
Installing headers
Headers, something that once only hotrodders and racers used, work more efficiently at extracting exhaust gases than traditional exhaust manifolds. That’s because headers use individual pipes for each cylinder, rather than combining pipes for two or more cylinders. On some modern engines, exhaust manifolds are designed to work more like headers.
Lengthening the exhaust pipe
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An OHV engine has a camshaft located where?
In the engine block over the crankshaft
“OHV†stands for overhead-valve. This means the camshaft is located in the cylinder block, above the crankshaft, rather than in the cylinder head. In such a setup, the camshaft operates long pushrods that reach up to rocker arms to operate the valves in the cylinder heads. The Chevrolet and Bentley V8s still OHV engine designs, so you know they can still make a lot of power.
Outside the engine block under the bottom of the pistons
Inside the engine block under the crankshaft
In front of the engine
What is the order of a four-stroke engine cycle?
Intake, exhaust, compression and power
Intake, compression, power and exhaust
In a “four-stroke†engine, which is all passenger car and most motorcycle engines today, (1) the intake stroke moves the piston downward, pulling the air-fuel mixture through the intake valves into the cylinder; (2) the compression stroke moves the piston upward to compress the mixture; (3) the spark plug ignites the mixture, creating the power stroke that pushes the piston downward, and (4) the piston moves back upward in the cylinder, pushing the combustion gases out through the exhaust valves.
Intake, power, compression and exhaust
Power, compression, intake and exhaust
Which of the following tools would be used to clean debris from threaded holes?
Sprocket cleaner
Straight-edge
Calipers
Taps
When working on or rebuilding an engine, you would use something called a “chaser†tap to clean or re-form existing threads. A “cutter†tap is used to create new threads. Both tools must be used very carefully.
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What attaches the piston head to the connecting rod?
The rocker arm
The wrist pin
The wrist pin (gudgeon pin if you live in the U.K.) is a kind of bearing that allows the connecting rod to pivot as the piston moves up and down.
The rod lobe
The flywheel
Which of the following is not an electric car?
Toyota Mirai
BMW i3
Honda Civic
Okay, this is a bit of trick question, since it’s not about engines, really. Honda does offer an electric vehicle, called the Clarity Electric (with a pitifully short battery range), but there’s no electric Civic. The Toyota Mirai is a fuel cell EV, meaning it generates its own electricity onboard through a reaction between hydrogen and oxygen.
Tesla Model S
What is the purpose of a catalytic converter?
It changes harmful gasses into less harmful gasses.
Catalytic converters have been used to control automobile exhaust pollution since the mid-1970s. Part of the exhaust system, today’s “three-way†catalytic converters use precious metals like platinum and palladium to convert harmful carbon monoxide, unburned hydrocarbons, and smog-causing nitrogen oxides into carbon dioxide, water, and harmless oxygen and nitrogen. If you see water dripping out of your car’s exhaust pipe, that’s the catalytic converter at work.
It mutes the sound of the engine.
It converts compressed natural gas into a liquid fuel.
It's used by California pollution stations to test engine emissions.
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If blue smoke is coming out of the exhaust pipes, which of the following is most likely the cause?
The spark plug gap is set wrong.
The piston rings are worn.
Blue smoke from a car’s exhaust pipe is a sure sign that oil is slipping past worn or damaged piston rings or valve seals and into the combustion chamber.
The head gasket is cracked.
The timing is off.
Which are the two most common engine configurations in cars today?
Horizontal and inline
V and horizontal
V and inline
Inline and V-type engines have long been the most common in cars. Examples today include inline-four, inline-six, V6, V8, and V12. Porsche sports cars (but not SUVs and sedans) use a “flat†or horizontally opposed cylinder layout, as do Subarus. Bentley and Bugatti use an oddball “W†configuration, which is based on the Volkswagen narrow-angle VR4 and VR6 engine design.
V and W
The Wankel engine is unique because of what?
It runs on water.
it runs on cooking oil.
It doesn’t have fuel injection.
It doesn't have pistons or valves.
Instead of converting reciprocating motion into rotational motion with pistons, connecting rods and a crankshaft, a Wankel (a.k.a. “rotaryâ€) engine uses elliptical rotors inside a small, barrel-shaped engine case. A Wankel has no camshafts, and instead of poppet valves operated by camshafts, there are stationary intake and exhaust ports that are alternately exposed and covered as the rotors spin on a shaft. It’s a far simpler and lighter design than a piston engine, but it tends to use more fuel and also burn oil.
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What is a ring compressor used for?
Expanding piston rings to fit over the piston.
It makes it easier to place o-rings.
Compressing piston rings.
Here’s another tool named for its single job. You use a ring compressor to hold and compress the piston rings as you install the piston into the cylinder bore.
It is an air compressor used to clean small places.
Which of the following is NOT an advantage of multi-valve engines?
They usually help increase the power compared to a two-valve engine.
They can operate at higher engine speeds.
The air exchange is better.
They have a lower manufacturing cost.
A piston engine pulls air in to be oxidized with fuel through combustion, so it makes sense that more valves let in more air. With four valves per cylinder, the two intake and two exhaust valves are individually smaller than the valves in a two-valve design, but together they have more surface area. Their smaller size has other benefits, as well. Compared to a two-valve engine, however, production cost is usually higher.
A four-stroke engine with which of the following number of valves would not be considered a multi-valve engine?
2
Any four-stroke engine must have at least two valves, one intake and one exhaust. Most modern car engines use four valves per cylinder, so this was called “multi-valve.†In the past, three- and even five-valve-per-cylinder engines have been used.
3
4
6
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The starter starts the engine using which principle?
Converting DC to AC power
Electromagnetic principles
A car’s starter is a small electric motor that turns the flywheel, therefore the crankshaft, to initiate the combustion process. An electric motor uses coil of wires around an electromagnet and turns when fed current.
Converting chemical energy into mechanical energy
Nuclear power principles
Which of the following is an advantage of poppet valves over sleeve valves?
They rock back and forth, so they are less likely to get jammed.
They are compact.
They have almost zero leakage.
Poppet valves, as opposed to sleeve valves last used in some cars in the 1930s, have almost no oil leakage. The name “poppet†is derived from “puppet,†a vague visual description for how the valves appear to operate.
They are cost-saving.
Engine cylinders fire in the correct order because of what?
The distributor cap and rotor
The spark plugs
The computer and coils
1 or 3 above
Don’t look for a distributor in a modern automobile engine. Beginning in the late 1980s, computers began taking over the task of distributing the electric current that fires the spark plugs. The computer activates individual coils for each cylinder to provide the current at just the right intervals.
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Which of the following is NOT a function of the correct firing order in an engine?
It improves fuel efficiency.
The optimal firing order depends on specific engine configurations, but in all cases it is chosen to yield an optimal combination of power production from the combustion cycles and minimal vibration.
It is designed to reduce vibrations.
It ensures power flows evenly.
It maintains engine balance.
What is the usual firing order for an inline 4-cylinder engine?
1-2-3-4
1-3-2-4
1-3-4-2
1-3-4-2 is the usual firing order for an inline four, although 1-2-4-3 is another acceptable but less frequently used order.
1-4-2-3
What is the purpose of a flywheel?
To maintain a steady engine speed
A flywheel is a heavy disc attached to the end of the engine’s crankshaft. As it turns with the crankshaft, its rotation essentially maintains the engine’s momentum and smooths out the power pulses as the individual cylinders fire.
To start the engine
To absorb the engine sound
To change transmission gears
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What are some disadvantages gasoline engines have compared to diesel engines?
Gasoline engines have a lower power-to-weight ratio than diesel engines.
Gasoline engines produce more carbon monoxide and are less efficient.
Diesel engines can be more fuel-efficient than gasoline engines, and they produce less carbon monoxide. However, these benefits are usually outweighed by the diesel producing more of other pollutants (including particulate matter), making more noise, weighing more and costing more to produce. Also, emission controls for diesels are more complex and more expensive than for gasoline engines. Just ask Volkswagen.
Gasoline engines are louder than diesel engines.
Gasoline engines are more expensive to buy.
What is the purpose of honing?
To ensure proper lubrication
When rebuilding an engine, you “hone†the cylinders, using a special tool to put a fine crosshatch pattern in the cylinder wall to help it retain lubricating oil across its surface area when the engine is operating.
To ensure smooth operation
To ensure a tight seal
To ensure force is transferred correctly
You Got:
/35
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