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