Engine: Description and Operation
Engine DescriptionThe 6.0L diesel engine is:
^ a four-cycle turbocharged V-8 with overhead valves.
^ 6.0 liter (365 cubic inch) displacement.
^ separated into two banks, the right bank numbered 1, 3, 5, 7 and the left bank numbered 2, 4, 6, 8.
^ rated at 325 horsepower and 560 ft. lbs. torque.
The cylinder block has been designed to withstand the loads of diesel operations by using:
^ a two-piece crankcase.
^ internal piston cooling oil jets.
^ a forged steel crankshaft.
^ powdered metal, fractured connecting rods.
The piston is:
^ made of an aluminum alloy.
^ fitted with an upper keystone compression ring.
^ fitted with a lower rectangular compression ring.
^ fitted with oil control rings.
The piston pins are:
^ a free-floating type permitting the piston pin to move/float freely in the piston pin bore.
^ retained in the piston by piston pin retainers.
The camshaft is:
^ supported by five insert-type camshaft bearings.
^ of the roller camshaft design.
^ driven by the crankshaft through the use of the crankshaft gear and the camshaft gear.
The hydraulic valve tappets:
^ minimize engine noise.
^ maintain zero valve lash.
^ incorporate camshaft follower guides.
^ incorporate a roller follower design that reduces camshaft wear.
The cylinder heads are designed:
^ to incorporate electrohydraulic fuel injectors.
^ to locate the fuel injectors in the center of the combustion chambers between the rocker arms.
^ with external high-pressure oil galleries.
The glow plug system is:
^ designed to preheat the cylinders for faster cold weather starts and smoke reduction.
^ controlled by the Powertrain Control Module (PCM) and glow plug control module.
^ mounted directly into the cylinder heads.
The optional block heater is:
^ designed to heat the engine coolant and oil for improved cold weather starts.
^ located near the starter.
^ powered by a 120 volt external power source.
^ replaceable, but not repairable.
The fuel injection system used on the engine:
^ is controlled by the Powertrain Control Module (PCM) and fuel injector control module.
^ utilizes a frame mounted horizontal fuel conditioning module.
^ circulates fuel through a combination fuel filter, fuel heater and water separator assembly.
^ uses eight electrohydraulic fuel injectors.
^ has a secondary fuel filter mounted on the engine.
^ has a fuel pressure regulator mounted in the secondary fuel filter housing.
The engine lubrication system:
^ is divided into two systems: the low-pressure system lubricates the engine, the high-pressure system actuates the fuel injectors.
^ is cooled by an engine oil cooler.
^ utilizes an Engine Oil Pressure (EOP) sensor and an oil pressure regulator.
6.0L Crankshaft, Camshaft and Piston
6.0L Front Cover, Rear Cover and Oil Components-Early Build
6.0L Front Cover, Rear Cover and Oil Components-Late Build
6.0L Front Cylinder Head and Rocker Arm Carrier
6.0L Valve Cover
Lubrication System-Low-Pressure
Low-Pressure Oil Flow-Early Build
Low-Pressure Oil Flow-Late Build
The lubrication system is pressure regulated, cooled and full flow filtered. In addition to providing engine lubrication, it supplies oil to the high pressure oil system to control fuel delivery in the fuel injectors.
The following sequence describes lube oil flow through the major oil system components:
1. Oil pan (sump).
2. Oil pick-up tube and screen.
3. The low pressure oil pump is a gerotor type contained in the front cover. The gerotor assembly consists of an outer and an inner gear. The inner gear is driven by the crankshaft. The pump inlet and outlet passages are through ports in the front cover.
^ Oil pressure regulator (bypass) controls lube oil pressure via a spring loaded plunger relieving oil back to the inlet of the pump once operating pressure has exceeded 517 kPa (75 psi).
4. The oil cooler cover receives oil from the oil pump and cools it in the oil cooler, which is located underneath the oil cooler housing.
^ The cooler bypass valves open in the event that the oil cooler base and/or cooler becomes restricted.
5. The oil filter housing contains a paper type element. Unfiltered oil flows up and around the outside of the filter and then down through the center stand pipe.
^ The oil filter bypass allows oil to pass directly to the main oil gallery should the filter become restricted.
6. Turbocharger and drive gears.
^ Cooled and filtered oil supplied from the oil cooler base lubricates the turbocharger bearings and provides hydraulic pressure for the variable geometry turbocharger control valve. Oil drains from the turbocharger through a drain tube back to the high pressure hydraulic pump cover.
7. Main galleries. Cooled and filtered oil supplied from the oil cooler base fills the main galleries to distribute oil to the following components via passages machined within the crankcase.
1 Hydraulic cam followers.
2 Camshaft main journals.
3 Crankshaft main journals.
4 Connecting rod bearings receive pressurized oil from the main bearings via drilled passages within the crankshaft.
5 Rocker arms receive their lube oil from the hydraulic cam followers via the push rods. Oil drains back to the sump through holes located in the cylinder head.
6 Piston cooling tubes.
8. High pressure hydraulic pump oil reservoir.
^ This reservoir (below oil cooler) has a constant supply of oil for the high-pressure oil pump. It has an approximate capacity of 0.9 Liters (0.95 quarts).
Lubrication System-High-Pressure
Lubrication System-High-Pressure-Early Build
Lubrication System-High-Pressure-Late Build
The high pressure oil system is composed of two subsystems:
^ Injection Control Pressure (ICP) system
^ Fuel injector assembly
The hydraulic force necessary to inject fuel into the combustion chamber is provided by the ICP system. The fuel injectors on the engine are hydraulically actuated and electronically controlled.
The ICP system is composed of the following components:
^ Oil reservoir
^ Oil pump assembly (high-pressure)
^ Oil pump cover
^ High-pressure tubes
^ High-pressure rail assemblies
^ Injection Control Pressure (ICP) sensor
^ Injection Pressure Regulator (IPR) valve
^ Check valves
The high-pressure oil pump receives engine lube oil from a reservoir cast into the rear of the crankcase. This reservoir makes available a constant supply of engine oil from the pump. This reservoir is constantly refilled by the low-pressure lube oil system with filtered oil from a passage in the oil cooler housing.
The high-pressure oil pump is mounted at the rear of the crankcase and is driven by the camshaft gear. Oil is drawn from the oil reservoir through a 150 micron screen and into a passage to the pump inlet port. High-pressure oil from the pump is distributed to the injectors through a series of tubes and manifolds.
The high-pressure discharge tube is mounted to the pump and serves to connect the oil flow from the high-pressure oil pump to the rear engine tube assembly. This tube assembly divides oil flow into two tubes or branches, one for each side of the engine. Rigid tubes in each branch direct oil up into the high pressure oil rail of each cylinder head. Oil from the rails enter the injectors through O-ring sealed ports at the top of each injector. When the injector opening coil is energized, high-pressure oil is used to push fuel into the combustion chamber. After injection is complete, the oil inside the injector is vented through the top portion of the injector and allowed to drain back to the oil sump.