ATASA 5 Intake & Exhaust Systems · Intake & Exhaust Systems Cranking the engine for 10 to 15 seconds with the ignition coil disabled will pump oil to the turbo charger. Some of the

ATASA 5 TH Study Guide Chapter 32 Pages 949977 Intake & Exhaust Systems 76 Points

ATASA 5 th Intake & Exhaust Systems Please Read The Summary

1. An engine not only needs ____ for combustion, it must also get __________ gases out of the cylinder.

ATASA 5 th Intake & Exhaust Systems

Air, Spent Fuel, Spent Exhaust, Air

2. __________ draws air into the cylinders & operates emission controls, brake boosters, & AC doors.


Exhaust Pressure Vacuum

3. Vacuum, measured in relation to ______________ pressure, is any pressure less than atmospheric.


Atmospheric Ocean Space

Vacuum refers to pressure less than atmospheric pressure at any given altitude.

Remember: Atmospheric Pressure minus MAP = Vacuum 29.0 Hg” – 11.0 Hg” = 18.0 Hg”

Also: 1 Bar = 100 KPa (kilo pascals)


Atmospheric pressure at sea level is 14.7 PSI or about 100 kPa. This reads 0 Hg” vacuum on a gauge.

Good facts to know about atmospheric pressure and units.

1 atm = 760 mm Hg = 29.92 inches


Normal atmospheric at sea level is also expressed as 1 bar.


Engine vacuum is highest at idle with the throttle plate closed and no load on the engine…vacuum leaks are most evident at idle RPM!

Manometer or “Utube”

05 Hg” at WOT

1822 Hg” at CT


Vacuum used to control vehicle systems can be controlled by electric solenoids, TVS’ & PVS’. (thermal vacuum switches & ported vacuum switches)


Vacuum gauges & vacuum pumps are important diagnostic tools.


Vacuum Transducer

4. Normal atmospheric pressure at sea level is ____ psi. Also expressed as 1 bar or 100 kilopascals.


5. Vacuum problems contribute to many _______________ problems.


Inability Driveability Permeability

5. Vacuum problems contribute to many _______________ problems.


6. At idle, a healthy engine should have ___ to ___ Hg” vacuum and should have 0 to 5 Hg” at WOT.


1722 Hg” at Closed Throttle

7. The air ___________ system directs outside air into the engine’s cylinders.


Reduction Induction Deduction

8. Air filters clean the air entering the cylinders and entering the crankcase through the _____ system.


9. __________ manifolds distribute clean air or an air/fuel mixture (TBI & Carb) to the cylinders.


10. Intake manifolds can be either ______ (with coolant passages) or ______ (without coolant passages).


11. With multiport EFI, intake manifolds can be made of either ___________ or __________, since fuel vaporization & fuel condensation are not concerns like in carbureted or TBI systems.


12. Some intake manifolds provide areas for mounting vacuum sources, and contain __________ passages for operation of the EGR system. They may also have connections for MAP, ECT, & IAT sensors.


13. An intake manifold has 2 basic components: 1) ______________ area and 2) ________________.


14. The plenum is a _______________ for air. Used extensively in the Atkinson cycle engine.


ATKINSON CYCLE Internal combustion cycle that enables the compression stroke and expansion strokes to be mechanically independent of each other.

15. An engine designed for maximum torque & horsepower at high speeds has ___________ runners.


16. Efficiently using the bouncing effect of air in the runners is called _____________ supercharging.


ACOUSTIC INDUCTION CONTROL Engine air intake system using a valve that intermittently closes or

restricts the flow of air to the cylinders, improving engine performance at some engine speeds.

17. Intake manifolds with variable length ___________ are controlled by electronic butterfly valves to provide changes in airflow volume & speed as engine needs change for various rpm.


18. Intake manifold ____________ (IMT) and intake manifold runner ___________ (IMRC) are both examples of variable manifolds that can increase the volumetric efficiency of an engine.


19. A leaking manifold gasket is one of the most common causes of internal ____________ leaks.


20. ________________ & _______________ are the 2 processes of artificially increasing the amount of airflow into the engine. This will increase volumetric efficiency and horsepower.

Normally aspirated engine = nonturbocharged or nonsupercharged


21. __________________ (airtoair or airtowater) are used to cool the air charge entering the engine.


22. Turbochargers use exhaust leaving the engine to spin the __________ or hot wheel. Both gasoline and diesel engines use turbochargers to compress that air before it enters the engine.


23. The turbine is attached through the center shaft to the ____________ or cold wheel.


24. Turbochargers provide a positive pressure increase, called ___________, in the intake manifold.


25. _______ _____ is the slight delay in response as the exhaust builds up enough energy to spin the turbo wheels fast enough to respond to the engine speed. (spooling up)


26. A ________ _______ is used to limit the boost by allowing some exhaust to bypass the turbine.



Internal Waste Gate

External Waste Gate

27. A waste gate can be controlled by __________ pressure or by the PCM in response to MAP.


28. MAP, CKP & KS inputs are indicators of when to limit turbo boost & when to _________ timing.


29. High temperatures and turbo speeds of up to ______________ rpm make lubrication & cooling important.


30. Variable _________ turbines & variable ___________ turbochargers provide more boost at lower engine speeds without overboosting at higher speeds. They do not need a waste gate.


31. Twin turbos, two different sized turbos, and ______stage turbos are all options being used.








32. A highpitched sound is the result of an ______ leak between the compressor & engine or exhaust leak between the engine & turbo.


33. Pressure testing can be done with ____________ or with a scan tool. Leak test with soapy water.


34. Most turbocharger failures are caused by lack of __________, ingestion of foreign objects (fingers) or contaminated lubricant. …infrequent oil changes can cause selfdestruction.



35. After storage, __________ the lubrication system before starting. Allow the engine to idle for 30 seconds to 2 minutes before shutting it down after a hard run to allow the shaft to cool.


Cranking the engine for 10 to 15 seconds with the ignition coil

disabled will pump oil to the turbo charger. Some of the things that should always be done after rebuilding or replacing a turbo include changing the oil and oil filter, checking the air filtration system for leaks or obstructions, and priming the turbo oil supply

before starting the engine.

36. _________________ are air pumps driven by the engine’s crankshaft through a belt system.


37. An ____________________ clutch is used to engage and disengage the supercharger from the drive belt.


38. Air is drawn into the _______ of a supercharger, _____________ by the spinning rotors, and exits through the top where it is routed to an intercooler and finally into the intake manifold.


39. Superchargers incorporate a ________ valve that allows it to idle when extra power isn’t needed.


40. Since rotor speed is directly linked to crank rpm, __________is directly controlled by throttle position. On an EEC engine, TPS is a main input to be monitored for turbo & supercharger ops.


41. The __________ supercharger with a pair of threelobed, helical rotors is the most popular design.


Engine oil coolers are often used on turbocharger & supercharger systems.


42. A supercharger normally has its own oil supply. True or False


43. A “____________” has both a supercharger for low speeds and a turbocharger for high speeds.


44. Proper tuning of exhaust manifolds can actually create a partial __________ to help draw exhaust gases out of the cylinder, improving volumetric efficiency, horsepower and torque.


45. Exhaust pipes are made of __________ steel, ____________ steel or zinc plated steel.


46. The __________ _________ is part of both the emission control system and the exhaust system.


47. The CAT contains cerium to store ____, platinum & palladium to oxidize ____ & ____, and rhodium to deoxidize or reduce ______. The abbreviation TWC stands for _________________.


48. A minicatalytic converter, located close to the engine is known as a ___________ CAT.


49. Upstream & downstream HO 2 S are used to monitor catalyst _____________ or effectiveness.

Remember: Upstream HO2S is for A:F Ratio Feedback & Control Downstream HO2S is the Catalyst Efficiency Monitor


50. Engine misfire can melt or plug a CAT. Loss of power & low ___________ are symptoms of this.


51. A fivegas exhaust __________ and a digital infrared thermometer or _______________ to measure CAT temperature are used to best diagnose a CAT.

1400 Fº Inlet Gas

100 Fº Hotter Outlet Gas


52. ____________ flow mufflers with internal baffles & chambers are used to quiet the exhaust.


53. Too much ________________ will reduce an engine’s volumetric efficiency or ability to breathe. Not enough backpressure may allow intake gases to leave the engine along with the exhaust.


54. ______________ or silencers are extra mufflers to change the tone of the exhaust or quiet it more.


55. ________ ____________ are used to protect other parts from the extreme heat inside the CAT.


56. Exhaust systems on FWD vehicles have ________ joints to allow the engine to roll from accelerating torque without moving the exhaust system along with it. (common breakage areas)


57. Exhaust systems are checked for restrictions by testing _________ _____________ with a gauge threaded into the upstream HO 2 S hole. Idle rpm back pressure <1.5 psi 2,500 rpm < 2.5 psi


58. A __________ machine can be used to identify small exhaust system leaks. (usually for EVAP tests)


59. Besides an oxyacetylene torch, some other common tools of the exhaust system trades are:


Exhaust systems contain AIR & EGR devices as well as the CAT with pre & post EGOS. (OBDII)

What is AIR?

What is EGR?


A properly functioning, working CAT should be 50°F or 8% hotter at its outlet than at its inlet.

1400 Fº Inlet Gas

100 Fº Hotter Outlet Gas


A CAT may contain a pipe from the AIR pump to the oxidation bed where fresh air can be used to lower HC & CO when it is injected

downstream into the platinum & palladium catalysts.

Air Injection Pump Injects air here


A malfunctioning CAT is pinpointed by upstream & downstream HO 2 S with the SAME output.

Upstream

Downstream

Good Catalyst Bad Catalyst







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ATASA 5 Intake & Exhaust Systems · Intake & Exhaust Systems Cranking the engine for 10 to 15 seconds with the ignition coil disabled will pump oil to the turbo charger. Some of the