C4.4 Industrial Engine Introduction Caterpillar


Introduction
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1.1. C4.4 Engine with Series Turbochargers
2.1. C4.4 Engine with Single Turbocharger

The C4.4 diesel engine is electronically controlled. The C4.4 engine has an Electronic Control Module (ECM) that receives signals from the fuel injection pump and other sensors to control the electronic unit injector. The fuel injection pump supplies fuel to the high-pressure manifold (Rail). The high-pressure manifold (Rail) distributes fuel to the electronic unit injectors.

The four cylinders are arranged in-line. The cylinder head assembly has two inlet valves and two exhaust valves for each cylinder. The ports for the exhaust valves are on the right side of the cylinder head. The ports for the inlet valves are on the left side of the cylinder head. Each cylinder valve has a single valve spring.

Each cylinder has a piston cooling jet that is installed in the cylinder block. The piston cooling jet sprays engine oil onto the inner surface of the piston to cool the piston. The pistons have a Quiescent combustion chamber in the top of the piston to achieve clean exhaust emissions. The piston pin is off-center to reduce the noise level.

The pistons have two compression rings and an oil control ring. The groove for the top ring has a hard metal insert to reduce wear of the groove. The skirt has a layer of graphite to reduce the risk of seizure when the engine is new. The correct piston height is important to ensure that the piston does not contact the cylinder head. The correct piston height also ensures the efficient combustion of fuel which is necessary to conform to requirements for emissions.

The crankshaft has five main bearing journals. End play is controlled by thrust washers which are on both sides of the number 3 main bearing.

The timing case is made of aluminum or cast iron. The timing gears are stamped with timing marks to ensure the correct assembly of the gears. When the number 1 piston is at the top center position of the compression stroke, the marked teeth on the idler gear will align with the marks that are on the fuel injection pump gear, the camshaft gear, and the gear on the crankshaft. There are no timing marks on the rear face of the timing case.

The crankshaft gear turns the idler gear which then turns the following gears:

  • the camshaft gear

  • the accessory drive gear (if equipped)

  • the fuel injection pump gear

  • the water pump gear

The camshaft runs at half the rpm of the crankshaft. The fuel injection pump runs at the same rpm as the crankshaft.

The fuel injection pump that is installed on the left side of the engine is gear-driven from the timing case. The fuel is transferred to the fuel injection pump by an external electric transfer pump. The electric transfer pump draws fuel across a suction strainer that supplies fuel to the primary fuel filter and the secondary fuel filter. The fuel then travels to the fuel injection pump. A pressure regulator that is installed in the low-pressure fuel system controls the fuel pressure to the fuel injection pump. The pressure regulator regulates the fuel at an absolute pressure of 150 kPa (22 psi) when the engine is at idle speed.

The fuel injection pump increases the fuel to a maximum pressure of 200 MPa (29000 psi). The fuel injection pump delivers the fuel to the high-pressure manifold (Rail). The fuel injection pump is not serviceable. The engine uses speed sensors and the Electronic Control Module to control the engine speed.

For the specifications of the C4.4 engine, refer to the Specifications, "Engine Design".

The following model views show a typical C4.4 engine. Due to individual applications, your engine may appear different from the illustrations.

C4.4 Engine with Series Turbochargers



Illustration 1g02409511
Typical example
(1) Front lifting eye
(2) Crankcase breather
(3) NOx Reduction System (NRS)
(4) Primary fuel filter
(5) Secondary fuel filter
(6) Electronic Control Module (ECM)
(7) Fuel priming pump
(8) Oil gauge (dipstick)
(9) Fuel strainer
(10) Oil filter
(11) Oil sampling valve
(12) Oil filler
(13) Fuel injection pump


Illustration 2g02409512
Typical example
(14) Rear lifting eye
(15) High-pressure turbocharger
(16) Low-pressure turbocharger
(17) Back pressure valve
(18) Starting motor
(19) Oil drain plug
(20) Exhaust outlet
(21) Flywheel housing
(22) Flywheel
(23) Exhaust gas cooler (NRS)


Illustration 3g02409862
Typical example
(24) Belt
(25) Connection for air inlet
(26) Coolant outlet connection
(27) Water temperature regulator housing
(28) Water pump
(29) Inlet connection for the coolant
(30) Crankshaft pulley
(31) Belt tensioner
(32) Alternator

C4.4 Engine with Single Turbocharger



Illustration 4g02407436
Typical example
(1) Front lifting eye
(2) Crankcase breather
(3) NOx Reduction System (NRS)
(4) Secondary fuel filter
(5) Primary fuel filter
(6) Fuel priming pump
(7) Fuel strainer
(8) Electronic Control Module (ECM)
(9) Oil filter
(10) Oil sampling valve
(11) Fuel injection pump


Illustration 5g02407536
Typical example
(12) Rear lifting eye
(13) Oil gauge (dipstick)
(14) Turbocharger
(15) Starting motor
(16) Oil drain valve
(17) Oil drain plug
(18) Back pressure valve
(19) Flywheel housing
(20) Flywheel
(21) Exhaust outlet
(22) Exhaust gas cooler (NRS)


Illustration 6g02407537
Typical example
(23) Oil filler
(24) Connection for air inlet
(25) Outlet connection for the coolant
(26) Water temperature regulator housing
(27) Water pump
(28) Inlet connection for the coolant
(29) Crankshaft pulley
(30) Belt tensioner
(31) Alternator
(32) Belt

Information System:

C4.4 Industrial Engine Lubrication System
Bench Test Procedure for Hydraulic Piston Pumps {0784, 5070}
C4.4 Industrial Engine Basic Engine
C4.4 Industrial Engine Cooling System
C4.4 Industrial Engine Air Inlet and Exhaust System - Series Turbochargers
568 GF and 568 LL Forest Machine Securing the Machine
C9.3 Engines for Caterpillar Built Machines Housing (Front) - Install
Installation of the 318-1497 Connecting Lines Gp {0679, 5057}
303.5D, 304D, 305.5D and 305D Mini Hydraulic Excavators Engine Supplement Turbocharger - Remove and Install
2010/05/10 Fuel Injection Nozzles for 3056E Engines {1251, 1290}
Installation of the 179-8703 Connecting Lines Gp {5057}
C9.3 Engines for Caterpillar Built Machines Cylinder Block Cover - Remove and Install
C4.4 Industrial Engine Fuel Injection
C4.4 Industrial Engine Power Sources
C4.4 Industrial Engine Electronic Control System
349F and 352F Excavators Hydraulic System Pump Control (Negative Flow) - Test
303.5D, 304D, 305.5D and 305D Mini Hydraulic Excavators Engine Supplement Fuel Transfer and Priming Pump - Remove and Install
374F Excavator Machine System Grease Lines
C6.6 Industrial Engine Fuel Priming Pump - Remove and Install - Electric Fuel Lift Pump (EFLP)
C6.6 Industrial Engine Fuel Filter Base - Remove and Install - Single Secondary Fuel Filter
C6.6 Industrial Engine Fuel Manifold (Rail) - Remove and Install
C6.6 Industrial Engine Fuel Injection Lines - Remove
C6.6 Industrial Engine Fuel Injection Lines - Install
C6.6 Industrial Engine Inlet Air Control - Remove - NRS Inlet Air Mixer