B3U1 Engine Systems Flashcards
What is the purpose of the engine block?
It houses all of the internal components of the engine.
What are the main journals?
The round surfaces on which the crankshaft rotates.
What two categories do rings fall?
(1) Compression.
(2) Oil.
Why does the cylinder head contain elaborate coolant passages?
To help remove heat from the combustion chamber.
Describe the movement in an engine’s stroke.
It can be in either direction, up or down.
What are the events for an engine?
Intake, compression, ignition, power, and exhaust.
To what does compression ratio refer?
The comparison in the volume of the combustion with the piston at BDC to the volume of the combustion chamber with the piston at TDC.
What does a two stroke engine use to pressurize the air in the air box?
External Blower
To what temperatures does compression causes the air in the combustion chamber to increase?
Above 1000 Degrees F
When is fuel injected into the cylinder?
Just before TDC
Why do four stroke engines not require an external blower?
A four stroke generated vacuum with the downward movement of the piston.
What components make up the battery ignition system?
(1) Battery.
(2) Ignition switch.
(3) Ignition coil.
(4) Breaker points.
(5) Condenser.
(6) Distributor.
(7) High-tension wire.
(8) Spark plug.
What does the secondary coil having more coils than the primary coil cause?
The secondary coil to build up much more voltage, up to about 25,000 volts, than the primary coil.
What does the fuel filters do?
Removes dirt and foreign particles from the gasoline.
What is the venturi?
The venturi is a restriction in the air passage.
What does the throttle valve do?
Regulates the amount of air/fuel mixture entering the cylinders by restricting the passage
Of what materials are gaskets made?
(1) Fiber cork.
(2) Synthetic rubber.
(3) Copper.
(4) Other soft metals.
What conditions are inspected on vibration dampeners?
Chips and cracks
What are signs of a combustion chamber leak when inspecting cylinder heads?
Discoloration and or rust around the combustion chamber Burned or warped valves, worn piston rings, and cylinder liners are some of the defects that cause a loss of compression.
What do improper adjustments to a carburetor cause?
(1) Engine backfires through carburetor
(2) Engine overheats
(3) Engine surges
(4) Engine misses
(5) Engine stops
(6) Engine turns over but fails to start
What are the causes of a gasoline engine to crank but not start?
(1) Engine flooded.
(2) Battery low.
(3) Empty fuel tank.
(4) Faulty fuel pump.
(5) Water, dirt or gum in gasoline.
(6) Faulty carburetor.
(7) Spark plug(s) fouled or wet.
(8) Spark plug(s) gap incorrect.
(9) Ignition cable disconnected or broken.
(10) Overheating shutdown switch faulty.
(11) Ignition cable wet or oil soaked.
(12) Spark timing incorrect.
(13) Vapor lock in fuel lines.
(15) Fuel solenoid fault
What are possible cuases that would cause an engine to surge?
(1) Carburetor flooding.
(2) Governor spring hooked into wrong hole in lever, or governor rod incorrectly
What is the initial adjustment you make to the low-speed air/fuel mixture?
Manufacturers reccomendation
What method of air/fuel ratio adjustments gives you the best results?
Vacuum guage method.
When do you make final valve adjustments?
After the engine reaches normal operating temperature
What do you adjust on the breaker points to correct the gap?
Stationary contact
Which engine component houses all of the internal components of the engine?
a. Head.
b. Block.
c. Oil pan.
d. Crankshaft.
B. Block
Which engine component converts reciprocating motion, up and down, into rotary motion, round and round?
a. Bearings.
b. Camshaft.
c. Crankshaft.
d. Rocker arms.
C. Crankshaft
Which engine component transfers the power of the piston to the crankshaft?
a. Flywheel.
b. Camshaft.
c. Valve train.
d. Connecting rod.
D. Connecting Rod
The engine component that forms the top of the combustion chamber is the
a. liner.
b. block.
c. piston.
d. cylinder head.
D. Cylinder head
The type of energy that the flywheel continually stores and releases to smooth the erratic operation of the engine is called
a. heat.
b. kinetic.
c. hydraulic.
d. pneumatic.
B. Kinetic
Which term describes a complete series of events?
a. Cycle.
b. Stroke.
c. Scavenging.
d. Compression ratio.
A. cycle
The position of the piston when it is at the highest point in its movement is best described by which term?
a. Scavenging.
b. Valve overlap.
c. Top dead center (TDC).
d. Bottom dead center (BDC).
C. top dead center (TDC)
Which term describes the position of the piston when it is at the lowest point in its movement?
a. Scavenging.
b. Valve overlap.
c. Top dead center (TDC).
d. Bottom dead center (BDC)
D. bottom dead center (BDC)
Which term describes the amount of time that both the intake and exhaust valves are open at the same time?
a. Cycle.
b. Scavenging.
c. Valve overlap.
d. Compression ignition.
Valve overlap
In a diesel engine, how high does the compression of the air causes the temperature to rise?
a. 120oF.
b. 212oF.
c. 500oF.
d. over 1,000oF.
D. Over 1000 degrees F.
On a two stroke engine, what creates the movement of intake air?
a. Blower.
b. Vacuum.
c. Centrifugal force.
d. Atmospheric pressure.
A. Blower
On a four stroke engine, what is the position of the valves and how is the piston moving during the exhaust event?
a. Both valves closed and the piston moving upward.
b. Both valves open and the piston moving downward.
c. Intake valve closed, exhaust valve open, and the piston moving upward.
d. Intake valve open, exhaust valve closed, and the piston moving downward.
c. Intake valve closed, exhaust valve open, and the piston moving upward.
Identify the component that provides an electrical spark in the combustion chamber at the proper time to ignite the air/fuel mixture.
a. Carburetor.
b. Spark plug.
c. Distributor cap.
d. Ignition system.
D. Ignition System
Which component prevents the voltage in an ignition system from arcing across the breaker points, causing them to burn?
a. Coil.
b. Magnetic.
c. Condenser.
d. Distributor.
C. Condenser
Identify a restriction in the passage of a carburetor that causes air to move faster.
a. Jets.
b. Nozzle.
c. Venturi.
d. Throttle.
C. Venturi
What causes a four stroke gasoline engine to operate in a lean condition?
a. An excess of fuel.
b. An excess of oil.
c. An excess of air.
d. Not have enough oil.
C. An excess of air.
Which troubleshooting choice is not a probable cause that a gasoline engine will not crank?
a. Short in electrical wiring.
b. Engine flooded.
c. Battery is low.
d. Faulty starter.
C. Battery is low
Identify the type of malfunction that occurs if a gasoline engine’s ignition firing order is incorrect.
a. Engine backfires through the carburetor.
b. Engine will not crank.
c. Engine overheating.
d. Engine knock.
A. Engine backfires through the carburetor.
What do you use to check the gap of breaker points to make sure it is at the specified distance?
a. Ruler.
b. Caliper.
c. Thickness gauge.
d. Inside micrometer.
C. Thickness Gauge
Which item fits into irregularities that exist on surfaces as you connect two engine components during engine maintenance?
a. Gaskets.
b. Wedges.
c. Lock tight.
d. Sealing compound.
A. Gaskets
Identify the reason you inspect a vibration dampener during engine maintenance.
a. Security only.
b. Cracks and chips only.
c. Security, cracks, and chips.
d. Security, paint, cracks, and chips.
C. Security, cracks, and chips
