[Diesel Engine Principles and Construction] Flashcards
What type of intake/exhaust valves used in internal-combustion engines have heads with conically shaped or beveled edges and a beveled seat? (gives the valves a self-centering action)
Poppet valves
What is the barrel in which an engine piston moves back and forth?
Cylinder liner
What are diagrams which show the relationship between pressures and corresponding piston positions?
Pressure-volume diagrams (indicator cards)
KTA 50
To prevent permanent starter motor damage, do not crank the engine for more than how many seconds?
30 seconds (wait 1-2 minutes before re-cranking)
What is wear of the adjusting screws usually caused by?
Loose locknuts
How many degrees of crankshaft rotation are involved in one stroke?
180 degrees
What stores up energy during the power events and releases it during the remaining events of the operating cycle? (absorbs energy of the crankshaft)
Flywheel
KTA 50
How is diesel fuel supplied to the injectors?
Fuel pump that is driven by the front camshaft (geared to the crankshaft
Which type of crown design is commonly used in marine engines?
Concave
KTA 50
What is the heat exchanger for coolant?
Keel cooler
On a 2-stroke, the camshaft turns at ___ the crankshaft speed.
Same speed as
KTA 50
What reduces or increases intake air temperature?
Aftercooler
What are the points which designate changes in direction of motion for a piston and crank called?
- Top dead center (TDC)
* Bottom dead center (BDC)
What are two satisfactory cleaning agents?
- Diesel oil
* Kerosene
What aids in sealing the cylinder to prevent the escape of gas?
Piston
KTA 50
Where is the oil cooler located?
In the “V” between the cylinders banks and under the aftercooler
What are the parts of the valve actuating mechanism that change the rotary motion of the camshaft to reciprocating motion to open the valves?
Cam followers
KTA 50
What is designed to keep the equipment in good working condition?
PMCS
What are the three types of piston pins?
- Stationary
- Semi-floating
- Full-floating
What are flat steel plates attached to each end of the cylinder block to add rigidity to the block?
End plates
How are diesel engines designated?
- Cylinders
- Bore
- Stroke
- Speed
more rarely, by displacement
_________________
6 x 3 3/4 x 5 x 1500
(Cylinders x Bore x Stroke x Speed)
KTA 50
How is the engine pressure-lubricated?
By a gear-type lube oil pump mounted to the block directly below the crankshaft and driven from the rear crankshaft gear
KTA 50
How many lube oil filters are there?
5 in parallel
What are the four piston strokes involved in a 4-stroke cycle?
- Intake
- Compression
- Power/Combustion
- Exhaust
What two factors make the period immediately after starting an engine critical for cylinder liners?
- Lack of lubrication
* Condensation of corrosive vapors
What receives the side thrust created by the movement of the crank and connecting rods, and aids in proper alignment of the piston in the cylinder?
Piston skirt
KTA 50
What is the operating temperature?
175-195 degrees Fahrenheit
KTA 50
What is circulated by a centrifugal water pump with mounted thermostats to control engine operating temperature?
Coolant
How is displacement calculated?
Piston Area x Stroke x Number of Cylinders
What are the main causes of burned valves?
- Carbon deposits
- Insufficient tappet clearance
- Defective valve seats
- Valve heads that have been excessively reground
On a 4-stroke, the camshaft turns at ___ the crankshaft speed.
1/2
Seven characteristics of a KTA 50
- Hp
- Idle RPM
- Max RPM
- # of cylinders
- # of strokes
- Fuel
- Cooling
- 1250 hp
- Idle RPM: 725 - 775 RPM
- Max RPM: 2100 RPM
- 16 cylinders
- 4-stroke
- Diesel
- Water-cooled
What are the two types of connecting rods?
- Conventional
* Fork and blade
What term identifies the sequence of events that take place in the cylinder of an engine for each power impulse transmitted to the crankshaft?
Cycle
What seal the cylinder and combustion space to prevent gases within the space from escaping until they have performed their function?
Compression rings
What term is used to identify an event which occurs in a cycle of operation?
Stroke
What prevents the formation of a ridge or lip on the water-jacketed liner surface at the upper point of ring travel?
Counterbore
KTA 50
What removes heat created during engine operation?
Coolant system
What seal the cylinder, distribute and control lubricating oil on the cylinder wall, and transfer heat from the piston to the cylinder wall?
Piston rings
KTA 50
What changes the rotating speed of the turbocharger turbine?
Changes in the energy level of exhaust gases
What are the two types of piston rings?
- Compression
* Oil
What are the three basic engine designs?
In-line, V-type, and opposed-piston
What provides high volume, low pressure air to the cylinder?
Blower
What is essential for proper engine operation?
Lubrication
What acts as the moving surface that changes the volume of the cylinder’s content, removes gases from the cylinder, and transmits the force of combustion?
Piston crown
KTA 50
1) What is the oil pressure at idle?
2) What is the oil pressure at the minimum rated RPM?
3) What is the oil pressure at the maximum rated RPM?
1) 20 psi
2) 45 psi
3) 70 psi
What causes the engine to misfire and produces unusual noises at the cam follower, push rod, and rocker arm?
Sticking valve
What serve as oil returns, permitting lubricating oil from the cylinder wall to pass through the piston into the crankshaft?
Oil drains
What do piston rings do?
- Seal the cylinder
- Distribute and control lubricating oil on the cylinder wall
- Transfer heat from the piston to the cylinder wall
What is the best method of determining whether excessive wear has taken place in a liner?
Measuring the cylinder liner with inside micrometer calipers
What are the two piston strokes involved in a 2-stroke cycle?
- Power
* Compression
What are the two types of liners and oil sumps?
- Dry
* Wet
What are cylinders lying in one plane called?
Bank
What serves to confine and release gases?
Cylinder assembly
KTA 50
What forces additional air into combustion chambers so the engine can burn more fuel and develop more horsepower than if it were naturally aspirated?
Turbocharger
What distribute oil to the cylinder wall in sufficient quantity to prevent metal-to-metal contact, and control the amount of oil distributed?
Oil rings
What feature is equipped with a spring-loaded pressure plate that is designed to release excess pressure in the event of a crankcase explosion or extreme pressure within the crankcase?
Safety cover
What are the common problems with valve assemblies?
- Sticking, bent, and burned valves
- Cracked and loose valve seats
- Weak and broken valve springs
- Worn valve keepers and retaining washers
- Broken valve heads
What can be used to determine the position of the crankshaft when the engine is being timed?
Flywheel rim degree markings
What can greatly help in finding cracks that would otherwise be invisible on valve springs?
Magnaflux
What are heavily-reinforced openings in the piston skirt, and serve as mounting places for the bushings or bearings which support the wrist pin?
Bosses
What hold the piston rings in position and keep them properly spaced?
Grooves and lands
What is used when one rocker arm opens two valves simultaneously?
Bridge
What type of engine has two connecting rods attached to each crankpin?
V-type
What is the movement from BDC to TDC, or from TDC to BDC?
Stroke
What are pistons made of?
Cast iron and aluminum
