This document summarizes the components and functioning of an engine's air induction and exhaust system. It describes the key parts of the air intake system including the air cleaner, turbocharger, aftercooler, intake manifold and combustion chamber. It also outlines the main components of the exhaust system like the exhaust piping, silencer and exhaust manifold. The document explains the requirements for proper air and exhaust system functioning, potential issues that can arise and their effects, as well as tips for troubleshooting problems.

1. AIR INDUCTION AND EXHAUST SYSTTEM
AIR SYSTEM FLOW
Air cleaner
Turbo charger
(compressor side)
After cooler/Intake manifold
Intake ports/valves
Combustion chamber
Exhaust piping
silencer
Turbo charger
(turbine wheel
Exhaust manifold
Exhaust valves/ports

2. Air system
• Function
• To supply air for complete combustion of fuel
• To take exhaust gases out of engine, hence divided into
two parts as
• Air intake system and Exhaust system
• Air intake system requirements
• Air supplied to the engine must be
• Sufficient- 1 ltr of fuel needs 12,500 ltrs of air for
complete burning. Oxygen in air is essential for burning
• Clean air- dust in air is harmful for engine-free of dust
particles
• Cool air- air at high temp will ignite fuel early, air at
high temp is thin and has less oxygen
• Dry air- air with moisture will have less oxygen,
moisture in combustion chamber is harmful to engine

3. Components in air intake system
• Air cleaner- element/housing
• Hump hose
• Suction pipe and vacuum indicator
• Turbocharger
• Air crossover connection
• Clamps
• After cooler/inter cooler
• Intake manifold
• Intake valves
• Combustion chamber

4. Air intake system
• Hump hose- leads the air from cleaner to turbo or
intake manifold-connects housing & suction pipe-
perfect sealing with the help of clamps-strong
enough to withstand vacuum
• Suction pipe- always under suction, transfers clean
air to turbocharger or intake manifold, vacuum
indicator mounted on it, even a hose can be
connected for remote vacuum indicator.
• Vacuum indicator- an easy way to know the
condition of air cleaner, red band is shown when
restriction beyond a limit, can be seen from a
distance.

5. Turbocharger
• Turbine casing and turbine wheel
• Impeller & casing
• Bearing housing
• Water cooled bearing housing also provided
• Rotates on the waste energy of exhaust gases
• Exhaust gases are directed on turbine wheel
• Clean air from air cleaner is pressurized by impeller wheel
• Advantages of a turbocharger
• More air-more fuel can be burnt-more power
• Better air/fuel ratio at all speeds-less pollution
• More air at lower speeds- better fuel combustion
• Self compensating at high altitudes
• Pressurized air manifolds – reduce combustion noise
• Utilizes energy from exhaust gases-more efficient
• Noise reduction- less noise

6. Crossover connection
• Leads the pressurized air from turbo to intake manifold,
always pressurized, sealed with clamps & gaskets
After cooler
• cool air means-more oxygen-more fuel- more power
• Fitted in housing or intake manifold
• A bundle of tubes to circulate engine coolant
• Pressurized hot air passes over this element
• Heat from air absorbed by coolant
• Drops the temp of air from 300* to 218* F
• Coolant flows inside the tubes
• Air flows through the fins
• Heat flow is from hotter fluid to colder fluid
• Chocking of tubes from inside or the fins from outside
will result in high intake air temperature

7. Intake manifold
• Leading air to the intake ports of cylinder heads
• Under suction in naturally aspirated engines
• Pressurized in turbocharged engines
• Sealing with gaskets
• Single or multiple configuration
• Distributes air evenly to all intake ports
Exhaust system
• Components in exhaust system
• Exhaust valves
• Exhaust manifold
• Exhaust piping
• Exhaust system supports
• Silencers/mufflers
• Rain caps

8. • Requirements of exhaust system operation
• Exhaust back pressure within the limits
• Noise reduction
• Prevent rain water entry into cylinder
• Exhaust piping support
• Lagging
Problems in air system and their causes/trouble shooting
• Trouble shooting tips
• An organized study of the problem
• For investigation & correction of difficulty
• Think before acting-study problem thoroughly
• Ask for any warnings, previous repairs, any similar trouble
before, is it safe to continue running engine
• Do easiest and obvious things first
• Double check before beginning disassembly
• Find and correct basic cause of trouble

9. • Blow – by means
• Combustion gases leak into crankcase due to wear of piston
rings/liners
• Blow-by results into –high crank case pressure
• Oil seal leakages
• Sludge formation in oil
• Improper lubrication of parts
• Reduced engine life
• Early engine overhaul
• High cost of overhaul
• Reasons for dust entry in combustion chamber
• Improper sealing of air cleaner element
• Porous/poor quality of paper element
• Torn air cleaner element
• Split tubing/piping
• Loose clamps
• Cracked hump hoses

10. • Use of broken gaskets
• Loose/cracked air intake manifolds
• Missing washers/wing nuts in air cleaners
Effects of dirt/dust entry in to engine
• Dirt forms abrasive paste oil
• Wear of piston rings/liners/valves/guides
• High lub oil consumption
• Excessive blow-by
Loss of power or engine not taking load
• Restricted air flow
• Incomplete combustion of fuel
• Engine not developing full H.P

11. Reasons for restriction to air flow
• Inlet cap/path obstruction
• Less diameter of air intake piping
• Excessive/sharp bends in intake systems
• Faulty location of air cleaner
• Poor quality of air filter/paper
• Chocked air cleaner element
Restrictions to air flow – tips
• Water manometer to measure restriction
• New element -8 to 15 inches of water
• Dirty element -25 inches of water
• Vacuum indicator showing red flag
• Avoid suction of leaking exhaust gases
• Never use torn element

12. Effects of restricted/less air to engine
• Incomplete combustion of fuel
• Heavy black smoke
• Low power/loss of power
• Hard starting/failure to start
• Reduced fuel economy
• Excessive lube oil consumption
• Carbon deposition in combustion chamber
Reasons for high back pressure
• Longer exhaust pipe lines
• Less pipe diameter
• Too many bends in the system
• Sharp bends
• Wrong location of silencer

13. Effects of excessive back pressure
• High combustion temperature causing early burning of
fuel…. Detonation… resulting in
• Piston crown burning
• Liner wall scuffing
• Piston rings scuffing
• Connecting rod bearing wear
Excessive back pressure results in
• Low power overheating(high coolant temperature)
• Poor fuel economy
• High engine wear rate
• Early bearing failure
• Carbon deposition on valves and pistons

14. Water entry or accumulation results in
• Hydraulic lock
• Early cylinder failure
• Rusted out pipe and fittings
• High noise level due to damages