Turbo charger Flashcards Preview

Cooling systems > Turbo charger > Flashcards

Flashcards in Turbo charger Deck (33):

Basic function of a turbo

utilizes exhaust gases and heat to drive a centrifugal air pump that increases air pressure of the air entering the intake manifold


five other things a turbo can do for and engine

helps operate at higher altitude
increase power without adding weight
increases power without needing larger engine
compensates for varying load demands
reduced exhaust gas and increases fuel economy


after cooler and intercoolers are used with turbo because

as air is compressed it heats up becoming less dense hot air must be cooled to get the best benefit from the increased air flow


as a result of the increased air flow to the cylinders

you will get increased turbulence as well aiding in the combustion process


difference of turbo over naturally aspirated

compression ratio is lower
cam and valve timing are changed to fully gain the benefits
injection timing is retarded
fuel injection pump out put or fuel injector size is increased
centrifugal fuel injection advance may not be required
crankcase vent could be vented to atmosphere


power out put of a turbo charged engine

may be as much as 50% more


turbocharger is often called a

centrifugal air pump


a turbo charger operates in direct proportion to engine speed true or false

as the amount of engine exhaust heats up the turbo speed will also increases


turbocharger components include

turbine housing , turbine wheel , compressor housing , compressor wheel


turbine housing

used to direct hot expanding exhaust gases to the turbine wheel causing the turbine shaft to rotate
due to high temps on the exhaust tide housing must be heat resistant usually made from cast


nozzle constructed of a series of veins is for

directing the flow of exhaust gas to the outer edge of the turbine wheel so it will receives constant force


wastegates are used for

diverting some of the exhaust gas from the turbine wheel to help maintain safe intake manifold pressure


compressor housing usually constructed out of

aluminium due to the lower heat on the intake side


diffuser plate used on the compressor side used for

helps direct the boost air to the intake manifold


why must the turbo charger get full oil flow right away

because when the engine starts up the turbo can reach high speeds soon after


how do some turbochargers stop internal oil from pushing past the seals during normal operation

with a wind back seal


why are piston rings used to seal turbo oil cavity

because of the high operating temps


why must radial and axial movements be kept with in spec

because the turbine or compressor wheels may come into contact with the housing


what must you do after running an engine with a turbo under loaded conditions

allow time for the turbo to cool down with system oil before shut down
a turbo that is cooled to fast may warp crack or have premature bearing failure


blue smoke from an engines exhaust

engine is likely burning oil
could be from worn piston rings or oil might be leaking into the compressor side of the turbo and feeding the engine


if the oil drain on the turbo was plugged

oil into the turbo could become pressurized and leak past the seals into the turbine or compressor housing


what is an important step to take when installing a new turbo

pre fill the turbo with oil and spin by hand to ensure it will have proper lubrication before start up


shut down procedure for turbo

run at half speed for 3 to 5 min
then idle for another 3 to 5 min
this allows engine oil to remove as much heat as possible before shut down


why must you cover turbo exhaust during transport

because air flow over exhaust turbine could cause the intake side to turn and premature bearing wear could ensue


where is the after cooler or intercooler usually located

after the turbo and before the cylinders


air to air coolers can reduce the heat of incoming air from

135 to 160 down to 43 degrees


why is an air to air more effective in cooling then a air to coolant

because the ambient temperature of the air moving through a air to air cooler is much lower then the temp of the coolant in the air to coolant system


one clue to coolant in the intake manifold

white smoke out the exhaust


why are waste gates and variable displacement turbochargers used

to control the amount of exhaust acting on the turbine to affect haw much boost or turbine speed you can have under various loads


waste gate function

senses the amount of boost pressure in the system and allows a specific value of exhaust gas to bypass the turbine controlling your maximum boost


two types of VDT

pivoting nozzle vain
sliding nozzle vain


Sliding nozzle vain operation

air actuated linkage controls the sliding nozzle back and forth controlling the amount of backpressure acting on the turbo


pivoting nozzle vain operation

air actuated vain open and close to controll the amount of exhaust gas back pressure acting on the turbine