Air Induction And Exhaust Systems Flashcards
What is central purpose of an air induction system?
Supply the engine with an ample supply of cool, clean air for combustion
An air induction can be composed of what parts?
Air cleaner(s), Pre-cleaner(s), Air filter(s), Dust ejection system(s), restriction indicator, filter housing(s), Inlet tubing, Clamp, Hoses, Cold/hot air intake systems, Manifold(s) and gaskets, Shutdown devices
What are the main functions of the air induction system?
Cleans the air supply, Silences the inlet airflow, Provides air for combustion, Cools air, it allows extra airflow when blowers and turbo’s are used.
Maximum engine performance occurs when air is less then?
33 C
2 stroke engines are considered to be:
Naturally aspirated, unless equipped with turbo
Engines without a turbocharger are considered to be?
Naturally aspirated
What factor can limit the volumetric efficiency of a engine?
Engine operating speed, Air humidity, Air temperature, Altitude, Liner and ring condition, Valve adjustment and cam condition, Air filter and inlet tubing condition
Naturally aspirated engines may have a volumetric efficiency of?
75-85%
Pre cleaners may be able to remove what percentage of large particles?
80%
What is called when exhaust gases cause the dust ejectors to dump?
Exhaust gas aspirator
What are the two types of air filter assemblies?
Wet or Oil bath
Dry type
How effective are each of the different types of air filter assemblies ?
Oil bath - up to 98.5%
Dry type - up to 99.5%
Dry filters are commonly constructed of what?
Pleated paper
Screw on constant torque clamp must extend how far?
1/4”
Seals and gaskets should:
Be replaced when components are disconnected
Air shutdown devices should only be used when?
In a emergency situation
Air shutdown devices should be inspected on a regular basis for?
Condition and freedom of movement
Components used in an exhaust system can include?
Manifolds and gaskets, Piping, Mufflers, Catalytic converters, particulate traps, Heat shields, Spark arrestors
When an exhaust system is routed past a cab or sleeper:
Components must be secure, leak free, quiet and not create vibrations
Exhaust manifolds are commonly constructed of what?
Cast iron
Straight through muffler
Allows exhaust gases to pass directly through a central tube in the muffler
Reverse flow muffler
Cause the exhaust gases to change direction as they pass through the inside of the muffler
Mufflers are typically constructed of?
Mild steel although stainless is becoming more common
Exhaust stack
is the point at which the exhaust gases leave the exhaust system
Stacks can sometimes have what? what is purpose?
Rain cap. Keep water and other contaminates out of the exhaust system
80% of cylinder wear related to contaminated air can be prevented by?
An effective pre-cleaner
When ideal combustion does not occur exhaust gases can include?
Carbon monoxide, Unburned fuel, Oxides of nitrogen, Carbon
12 ounces of dirt has the ability to?
Destroy an engine
Loose, missing or incorrect fasteners on an exhaust system are likely to cause?
Leakage problems
A faulty induction or exhaust system can cause what 3 major problems?
Lack of power
Black smoke
Premature engine wear
Blue smokes tends to indicate what?
Oil is being burnt
Incomplete combustion is generally the result of what?
Incomplete combustion
What is the purpose of a pre-cleaner
Remove large dirt and dust particles from the incoming air stream, reducing the load on the main air filter
What is the primary function of the exhaust system?
Gather exhaust gases from cylinders, direct them to silencing mechanism, then disperse them to atmosphere
T/F Fibreglass packing is used in some mufflers to absorb sound waves?
True
What device is used for testing restrictions on an air induction system?
Water manometer
