Navistar N13 - Engine Description

10ENGINESYSTEMS
HeavyDutyOnBoardDiagnostics(HD-OBD)
TheEPAhasaddednewregulationsfor2010to
reduceheavydutyvehicleemissions.TheHD-OBD
systemisdesignedspecicallyforelectronically
controlledheavydutyengines.ThegoalforHD-OBD
regulationistokeepengineemissionsinspecication
foraslongasagivenvehicleisinuse.
HD-OBDislegislatedtobeimplementedinthree
phases:
•2010:FirstengineforeachOriginalEquipment
Manufacture(OEM)becomesfullycertied.
•Theleadengineisdeterminedbyalegislated
equationbasedonprojectedsalesvolume&
usefullifeoftheengine.
•ForNavistar®,thisistheEPA2010
®
N13
engine.
•2013:Oneengineineachenginefamilybecomes
fullycertied.
•Thiswillbethelargeststepofthethree
phases.
•2016:AllenginesmustbefullyHD-OBDcertied.
TheHD-OBDsystemcontinuouslymonitorsforproper
engineoperation,andwillalertthevehicleoperatorto
emission-relatedfaultsusingtheMalfunctionIndicator
Lamp(MIL).
TheMILisinstalledintheElectronicInstrument
Cluster.Whenadetectedemissionsfaultoccurs,
theMILwillbeilluminated.Diagnosticinformationis
alsostoredintheEngineControlModule(ECM),and
maybeaccessedbythetechnicianfordiagnosisand
repairofthemalfunction.Diagnosticinformationis
accessedbyconnectingtheElectronicServiceT ool
(EST)tothein-cabDiagnosticConnector.
EngineDescription
TheNavistar
®
N13dieselengineisdesigned
forincreaseddurability,reliability,andeaseof
maintenance.
Thecylinderheadhasfourvalvespercylinderfor
increasedairow.Theoverheadvalvetrainincludes
rockerarmsandvalvebridgestooperatethefour
valves.Thefuelinjectoriscentrallylocatedbetween
thefourvalves,directingfueloverthepistonfor
improvedperformanceandreducedemissions.
Theoverheadcamshaftissupportedbyseven
bearingsinthecylinderhead.Thecamshaftgear
isdrivenfromtherearoftheengine.Theoverhead
valvetrainincludesrollerrockerarmsanddualvalves
thatopen,usingavalvebridge.
Navistar
®
N13enginesuseone-piecesteelpistons.
Allpistonsuseanoffsetpistonaxisandcentered
combustionbowls.Crownmarkingsshowcorrect
pistonorientationinthecrankcase.
Theone-piececrankcaseusesreplaceablewet
cylinderlinersthataresealedbydualcreviceseals.
Thecrankshafthassevenmainbearingswithfore
andaftthrustcontrolledatthesixthbearing.One
fracturedcapconnectingrodisattachedateach
crankshaftjournal.Thepistonpinmovesfreelyinside
theconnectingrodandpiston.Pistonpinretaining
ringssecurethepistonpininthepiston.Therearoil
sealcarrierispartoftheywheelhousing.
Agerotorlubeoilpumpismountedbehindthefront
coverandisdrivenbythecrankshaft.Pressurized
oilissuppliedtovariousenginecomponents.All
Navistar
®
N13enginesalsouseanengineoilcooler
andacartridge-styleengineoillter,whichare
installedintheenginelubeoilmodule.
Thelow-pressurefuelpumpdrawsfuelfromthe
fueltank(s)throughachassismountedlter/water
separator.Thelow-pressurefuelpumpprovidesfuel
fortheenginemountedfuelmodule.Conditioned
low-pressurefuelissuppliedfromtheenginemounted
fuelmoduletothehigh-pressurefuelpump,InletAir
Heaterfuelsolenoid,andtheAFTfueldosermodule.
Thehigh-pressurefuelsystemisadirectfuelinjected
common-railsystem.Thecommon-railincludesa
high-pressurefuelpump,twofuelrailsupplylines,
fuelrail,sixfuelinjectors,andpressurereliefvalve.
Thefuelinjectorsareinstalledinthecylinderhead
underthevalvecoverandareelectronicallyactuated
bytheECM.
Navistar
®
N13enginesuseadualstage,xed
geometryturbochargerassembly.Eachstage
includesaChargeAirCooler(CAC).TheHigh
Pressure(HP)turbochargerincludesapneumatically
operatedwastegate.TheLowPressureChargeAir
Cooler(LPCAC)ismountedonthelowerrightside
oftheengine,andusestheenginecoolingsystemto
regulatechargeairtemperatures.TheHighPressure
ChargeAirCooler(HPCAC)ismountedinfront