190201a Engine Fundamentals Flashcards
how many years ago was the first internal combustion developed
200
internal combustion engines convert heat energy of fuel into
useable mechanical energy and wasted heat
the term compression ignition refers to
the method of igniting fuel in a diesel engine
the term torque could best be described as a
rotational force
what is the swept volume of a single cylinder referred to as?
piston displacement
the compression ratio would be about _______ times that of a gas engine
2 times
a dirty air filter would do what to the Volumetric efficiency of an engine
decrease it
horsepower is a measurement of
the rate of doing work
What is the general rule of thumb for engine thermal efficiency
1/3 work 1/3 cooling 1/3 lost to exhaust
the term stroke refers to
distance piston moves from TDC to BDC
scavenging is a term that refers to
removing exhaust gases from the cylinder
what is the term for the degrees that intake and exhaust valves are open/
valve overlap
rpm and fuel output are controlled on a diesel by
regulating fuel quantity
cam on a 4 stroke rotates at _________ crankshaft speed?
1/2
main purpose of a turbocharger is to increase _______?
volumetric Efficiency
area = bore squared x 0.7854 or ?
A = π x r squared
you calculate piston displacement by what formula
area X stroke
amount of air taken into a cylinder during the intake stroke divided by the actual volume is known as?
volumetric efficiency (expressed in a percentage)
1 BTU = ___________ kj.
1.055 Kj
1 hp = __________watts.
746 watts
the bore of the engine refers to the
diameter of the cylinder
Imperial inches (in)
S.I. (metric) millimeters (mm) or centimeters (cm)
what is meant by a naturally aspirated induction system?
outside air pressure is used to fill the cylinder
the ability of an engine to convert the heat energy of the fuel to usable heat energy to push the piston is known as?
Thermal efficiency
the stroke of an engine is
twice the throw
What are the three types of horsepower
- indicated (ihp)
- frictional (fhp)
- brake horsepower (bhp)
bhp = ihp - fhp
as soon as the exhaust valve opens and release pressure is called
blow down
blower scavenging on a two stroke engine requires
a positive displacement air pump
maximum pressure is obtained at approximately _______ after TDC
23 degrees
on power stroke at what degree is maximum pressure obtained approximately?
20 - 25 degrees
what are the two different ways to cool the intake air on a diesel engine?
Intercooled (air to air)
Aftercooled (air to coolant)
the effective power stroke of a two stroke cycle engine is limited to approximately ____ to ____of crankshaft rotation.
90 t0 95 degrees
the effective power stroke of a four stroke cycle engine is limited to approximately ____ to ____of crankshaft rotation.
120 to 140 degrees
in order for a two stroke cycle diesel engine to scavenge, the must have?
positive inlet pressure
internal combustion engine dissipates approximately 60% of the heat developed by combustion through?
cooling and exhaust systems
what are the three types of horse power?
indicated horsepower
frictional horsepower
brake horsepower (bhp = ihp - fhp)
compression ratio of a gas engine?
8:1 to 9:1
compression ration of a diesel engine?
14:1 to 23:1
as soon as the exhaust valve opens and exhaust pressure is released in a two stroke cycle diesel, is called?
blow down
the term stroke refers to?
the distance a piston travels from TDC to BDC
the ability of a diesel engine to convert the heat energy if the fuel into useable heat energy to push the piston down.
thermal efficiency
what does naturally aspirated mean?
air enters the inlet manifold under atmospheric pressure
what is scavenging?
the removal of exhaust gas from the cylinder
