MEC 155 Lesson 1 (Elements)

Comprehensive fill-in-the-blank practice flashcards covering internal combustion engine classifications, cycles, fuel systems, components, and mechanical configurations.

An internal combustion engine is a heat engine in which the burning of fuel occurs in a confined space called a __________.

combustion chamber

When fuel burns inside an internal combustion engine cylinder, an __________ reaction of fuel with an oxidizer creates gases of high temperature and pressure.

exothermic

In early internal combustion engine development prior to the electric spark plug, various forms of __________ were used to initiate combustion from an external flame.

torch holes

The air-fuel ratio for a Spark Ignition (SI) engine typically ranges from $6$ to __________.

$$19$$

The combustion process in a Compression Ignition (CI) engine initiates when the air-fuel mixture self-ignites due to high temperature caused by high __________.

compression

The air-fuel ratio for a Compression Ignition (CI) or diesel engine typically ranges from $18$ to __________.

$$70$$

A four-stroke engine cycle experiences four piston movements over __________ engine revolutions for each cycle.

two

A two-stroke cycle engine executes its full cycle through two piston movements over __________ engine revolution.

one

In a two-stroke cycle engine, the second stroke comprises expansion/power stroke, exhaust blowdown, and intake and __________.

scavenging

The engine design shown in the diagram, featuring a triangular rotor turning inside a nonrotating block (stator), is known as a __________ engine.

rotary

In-line or straight engines position cylinders one behind the other along the length of the crankshaft and typically consist of $2$ to __________ cylinders or more.

$$11$$

In a V-engine, the angle between the two banks of cylinders along a single crankshaft typically ranges from $15^\circ$ to $120^\circ$, with __________ being the most common range.

$$60^\circ\text{ to }90^\circ$$

A W-engine is constructed similarly to a V-engine except that it features __________ banks of cylinders operating on the same crankshaft.

three

An __________ engine features two pistons in each cylinder with the combustion chamber located in the center between them, producing two simultaneous power strokes.

opposed piston

The cylinder configuration shown in the diagram, where pistons are arranged circularly around a central crankshaft and linked to a master rod, is a __________ engine.

radial

A bank of cylinders on a radial engine always possesses an __________ number of cylinders ranging from $3$ to $13$ or more.

odd

An engine with no intake air pressure boost system that relies entirely on atmospheric pressure is classified as __________.

naturally aspirated

In a supercharged engine, intake air pressure is boosted by a compressor mechanically driven off the engine __________.

crankshaft

In a turbocharged engine, the intake air compressor is driven by a turbine powered by the engine's __________.

exhaust gases

A __________ is a venturi flow device that meters fuel into the incoming air flow via a pressure differential.

carburetor

In a multipoint port fuel injection system, fuel injectors are mounted directly adjacent to the __________ of each cylinder.

intake valves

Gasoline is the light distillate fraction of crude petroleum and constitutes approximately __________% of the processed crude.

$$43$$

While regular unleaded gasoline has a greenish or slightly bluish hue, premium (high-octane) gasoline has a __________ color.

pinkish

Diesel fuels are petroleum distillates that boil in the temperature range of $200^\circ\text{C}$ to __________.

$$370^\circ\text{C}$$

Red diesel (marked diesel or gas oil) is legally designated specifically for __________ applications such as marine vessels and agricultural equipment.

offroad

Natural gas obtained directly from oil wells is specifically termed __________ gas.

casing-head

Autogas is an LPG fuel formulated from a varying mixture of propane and __________.

butane

The alternative fuel blend E10 (gasohol) consists of $10\%$ ethanol and __________% gasoline.

$$90$$

In four-stroke cycle engines, the camshaft rotates at __________ engine speed.

half

A Single Overhead Camshaft (SOHC) engine regulates the inlet and outlet of gases using a single camshaft, whereas a Double Overhead Camshaft (DOHC) engine uses __________ camshafts.

two

The combustion chamber volume is at its minimum when the piston is located at __________.

TDC

Cylinder liners that directly come in contact with the liquid coolant inside the water jacket are classified as __________ sleeves.

wet

In an engine intake manifold, an individual delivery pipe feeding a single cylinder is termed a __________.

runner

The heavy rotating wheel connected to the crankshaft that stores kinetic energy and furnishes large angular momentum to smooth operation is the __________.

flywheel

The component shown in the image, used to preheat the combustion chamber in a diesel engine for cold starts, is a __________.

glow plug

In large reciprocating engines, the piston rod connects the piston to the crankshaft via an intermediate joint known as a __________.

crosshead

Combustion gas that forces its way past the piston rings into the crankcase is referred to as __________.

blowby

The mechanical pin used to pivotally fasten the connecting rod to the piston body is called the __________.

wrist pin

The sealing element shown in the image, installed between the cylinder head and engine block to prevent fluid leaks, is the __________.

head gasket

The maximum theoretical number of main bearings in an engine block equals the number of cylinders plus __________.

one

Most automotive reciprocating internal combustion engines employ spring-loaded valves called __________ valves.

poppet

The most common design of belt-driven positive displacement supercharger is the __________ supercharger.

Roots

A heat engine in which the burning of fuel occurs in a confined space called a combustion chamber is known as a(n) __________.

Internal Combustion Engine

In a Spark Ignition (SI) engine, the air-fuel ratio typically ranges from __________.

$$6\text{ to }19$$

In a Compression Ignition (CI) engine, the air-fuel ratio typically ranges from __________.

$$18\text{ to }70$$

In the engine cycle shown, ignition is initiated purely when fuel is sprayed into air heated by __________.

high compression

A four-stroke cycle experiences four piston movements over __________ engine revolution(s) for each cycle.

$$2$$

A two-stroke cycle completes its full operational cycle with two piston movements over __________ engine revolution(s).

$$1$$

The engine design shown, which features a non-concentric rotor revolving inside a non-rotating stator block containing the combustion chambers, is called a(n) __________.

Rotary Engine

In a V-Engine, the angle between the two banks of cylinders can range from $15^\circ$ to $120^\circ$, with __________ being the most common angle range.

$$60^\circ\text{ to }90^\circ$$

A W-Engine features __________ banks of cylinders mounted on the same crankshaft.

three

An engine configuration having two pistons in each cylinder with the combustion chamber located in the center between them is classified as a(n) __________ engine.

Opposed Piston

In the radial engine configuration shown, the connecting rods of the pistons are connected to a central __________ rod.

master

A single bank of cylinders on a radial engine always consists of a(n) __________ number of cylinders ranging from 3 to 13 or more.

odd

An engine that does not use an intake air pressure boost system and relies solely on atmospheric pressure is known as __________.

Naturally Aspirated

The forced-induction system shown increases intake air pressure using a compressor driven mechanically off the engine's __________.

crankshaft

The forced-induction system shown increases intake air pressure using a turbine-compressor driven by the engine's __________.

exhaust gases

A two-stroke cycle engine that uses the __________ as an intake air compressor is referred to as crankcase compressed.

crankcase

The fuel-metering device illustrated, which utilizes a venturi and pressure differential to meter fuel into the airflow, is a(n) __________.

carburetor

In a Multipoint Port Fuel Injection system, the fuel injectors are mounted directly adjacent to the __________ of each cylinder.

intake valves

Gasoline is the light distillate fraction of crude oil that represents approximately __________% of the crude oil processed.

$$43$$

Regular unleaded gasoline is identifiable by its __________ hue.

greenish or slightly bluish

Premium (high-octane) gasoline typically has a(n) __________ color.

pinkish

Diesel fuel is composed of petroleum distillates boiling in the range of __________.

$$200^\circ\text{C}\text{ to }370^\circ\text{C}$$

The dyed fuel used for off-road applications such as marine vessels and stationary engines is known as __________ Diesel.

Red

Natural gas obtained directly from oil wells is known as __________ Gas.

Casing-Head

Natural gas from which gasoline has been extracted or recovered is called __________ Gas.

Dry

Autogas is an automotive fuel composed of a varying mixture of __________.

propane and butane

The standard gasohol fuel blend known as E10 contains 10% ethanol and __________% gasoline.

$$90$$

In a four-stroke cycle engine, the camshaft rotates at __________ engine speed.

half

An engine configuration featuring two camshafts per cylinder bank—one exclusively for inlet valves and one for outlet valves—is called a(n) __________ engine.

DOHC

A chamber located in the exhaust stream that contains catalytic material to promote emissions reduction via chemical reaction is a(n) __________.

catalytic converter

The combustion chamber volume is at its minimum when the piston is positioned at __________.

TDC

Standard automotive engine coolant typically consists of a 50/50 mixture of water and __________.

glycol

Cylinder liners that do not come into direct contact with the liquid in the water jacket are classified as __________ sleeves.

dry

In an intake manifold, an individual pipe feeding air or mixture to a single cylinder is called a(n) __________.

runner

The rotating mass with a large moment of inertia connected to the crankshaft to store energy and smooth operation between power strokes is the __________.

flywheel

A small electrical resistance heater positioned inside the combustion chamber of CI engines to preheat the chamber during cold starts is a(n) __________.

glow plug

In large reciprocating engines, the piston connects to the connecting rod via an intermediate assembly shown, consisting of a piston rod and a(n) __________.

crosshead

High-pressure combustion gases that leak past the piston rings and into the crankcase are called __________.

blowby

In the piston assembly shown, the upper surface exposed to combustion is the crown, and the cylindrical side surface is the __________.

skirt

The pin that fastens the piston to the connecting rod is commonly referred to as the piston pin or __________.

wrist pin

The theoretical maximum number of main bearings in an internal combustion engine is equal to the number of pistons plus __________.

one

The ignition component shown generates a high-voltage electrical discharge across the __________ to initiate combustion in an SI engine.

electrode gap

A butterfly valve mounted upstream in the air intake system of an SI engine to control airflow volume is known as the __________.

throttle

The spring-loaded valve assembly shown, which is pushed open by camshaft action and seals against a valve seat, is a(n) __________ valve.

poppet

The three supercharger configurations depicted are the Roots, the Lysholm Twin Screw, and the __________ supercharger.

centrifugal

In the turbocharger assembly shown, exhaust gas turns the turbine wheel to rotate a shared shaft driving the __________ wheel, which pressurizes the intake air.

compressor