module 9

Which of the following is used to determine engine size (displacement)?

Cylinder bore, piston stroke, and number of cylinders.

A circle equals 180 degrees.

F

An engine in which the bore is larger than the stroke is an undersquare engine.

F

A larger bore and stroke makes the engine more powerful.

T

Compression ratio is a comparison of cylinder volumes at BDC and TDC

T

Compression stroke pressure is an indicator of engine condition.

T

Engine displacement is the piston displacement times the number of cylinders in the engine.

T

Technician A says as altitude above sea level increases, more air is forced into a normally aspirated engine. Technician B says as altitude above sea level increases, atmospheric pressure decreases. Who is right?

b only

Technician A says that horsepower is actually a measurement of torque. Technician B says that horsepower ratings are used in the United States. Who is right?

b only

Technician A says that horsepower varies with engine speed. Technician B says that torque varies with engine speed. Who is right?

both a and b

Technician A says that piston movement on the intake stroke creates vacuum. Technician B says that manifold vacuum can be used to diagnose some engine problems. Who is right?

both a and b

Torque is measured at the engine ____.

crankshaft

All of the following are measures of engine displacement, except:

cubic millimeters

Piston protrusion is a critical measurement on ____ engines

diesel

Brake horsepower is measured at the ____.

engine crankshaft

turning force, torque cylinder diameter, bore a measure of engine power killowats total piston travel. stroke negative pressure. vacuum

k

When the piston in a given engine is at BDC, the cylinder volume is 30 cubic inches. When this piston reaches TDC, the cylinder volume is 5 cubic inches. What is the compression ratio of this engine?

maybe 6:1

Technician A says, generally speaking, a diesel engine has lower compression than a gasoline engine. Technician B says that lower compression ratios reduce power. Who is right?

maybe b

Piston displacement is a measure of ____.

volume