Stationary Engine Fundamentals Module Flashcards
True or False;
The engine flywheel should be pinned and locked out before entering the crankcase?
True
Before performing maintenance on a recently run engine, what must you do?
Disconnect any electrical feed and close, lock, tag and purge all gas sources
True or False;
When working in areas of high concentrations of hydrogen sulphide(h2s), you should always wear a personal alarm monitor?
true
The thermal efficiency of an engine is best described as the ability of the engine to;
Change the energy in the fuel to usable heat energy and power
The amount of air an engine can take into the cylinder compared with the volume of the cylinder is called ______________.
Volumetric efficiency
The description of compression ratio is best stated as;
The cylinder volume plus the combustion chamber volume, divided by the combustion chamber volume.
On a 2-stroke engine with 6 cylinders and a firing order of 1-5-3-6-2-4, the running mates would be?
There would be no running mates as it applies to 4-strokes only.
The displacement of a 6 cylinder engine with a 5 inch bore and 6 inch stroke is;
Engine displacement = area of bore x length of stroke x # of cylinders
bore: 5/2 = 2.5²
stroke = 6
# of cylinders = 6
= π x 2.5² x 6 x 6
=706.85in3
When comparing a Diesel engine to a gas engine, the:
-compression pressures and compression ratios may be twice as high or greater in a diesel
-diesels are heavier
When air is compressed, what are the noticeable effects?
The temperature increases, as the volume becomes smaller
The SI metric system measures pressure in?
Pascals
Pressure (P) = Force (F) / Area (A)
When you are determining engine rotation using the SAE standard, you view the engine from:
The main power end of the engine.
What type of head design has the valves in the block?
L head engine (flat head)
True or False;
Indicated horsepower is the power at the flywheel of the engine.
False - indicated HP is theoretical power of an engine
True or False;
A two-stroke engine completes one cycle in 720 degree rotation
False
360 = 2 stroke
720 = 4 stroke
True or False;
Potential energy is the energy resulting from the motion of an object.
False
Kinetic energy is energy resulting from the motion of an object
True or False;
An under square engine is an engine with a larger stroke than bore.
True
True or False;
Blow-by is leakage past the rings
True
True or False;
Running mates are pistons that reach TDC at the same time.
True
True or False;
The basic requirements for combustion are air, spark and compression.
False - fuel, air, ignition
True or False;
The fuel must be atomized and mixed with air to be burned.
True
True or False;
At the end of the exhaust stroke, the intake and exhaust valves are open at the same time.
True
True or False;
A 2 stroke engine makes twice as much power as a four stroke engine of the same capacity.
False - does not, because the effective power stroke is shorter than a 4 stroke.
True or False;
Spark-ignition engines have a much lower compression ratio than Diesel engines.
True
True or False;
The classification for an engine with a normal operating speed of 800 rpm is a low-speed engine.
False - Medium speed
Low speed - under 500rpm
Medium 500-1000rpm
High - over 1000rpm
True or False;
Integral engines require proper alignment with the driven equipment
False - driven equipment is built into engine
True or False;
On a horsepower-torque curve, the high point of the torque curve indicates the approximate rpm for maximum volumetric efficiency.
True
What causes air to flow into the engine?
The piston creates low pressure when moving downward.