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| Illustration 1 | g01329939 |
Front left engine view (1) Fuel manifold (Rail) (2) Canister for the crankcase breather (3) Electronic control module (4) P2 connector (5) Secondary fuel filter (6) Hand primer (7) Primary fuel filter (8) Oil sampling valve (9) Oil filter (10) Fuel pump (11) Water pump (12) Damper (13) Fan (14) Fan pulley (15) Belt tensioner | |
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| Illustration 2 | g01329941 |
Rear right engine view (16) Oil gauge (17) Air intake (18) Oil filler (19) Front lifting eye (20) Alternator (21) Exhaust manifold (22) Exhaust elbow (23) Turbocharger (24) Wastegate solenoid (25) Starting motor (26) Oil pan (27) Drain plug (oil) (28) Drain plug or coolant sampling valve (29) Breather (30) Rear lifting eye | |
The C6.6 diesel engine is electronically controlled. The C6.6 engine has an Electronic Control Module (ECM) that receives signals from the fuel injection pump and other sensors in order 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 six 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 in order to cool the piston. The pistons have a Quiescent combustion chamber in the top of the piston in order to achieve clean exhaust emissions. The piston pin is off-center in order 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 in order to reduce wear of the groove. The skirt has a layer of graphite in order to reduce the risk of seizure when the engine is new. The correct piston height is important in order 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 in order to conform to requirements for emissions.
A piston and a connecting rod are matched to each cylinder. The piston height is controlled by the distance between the center of the big end bearing and the center of the small end bearing of the connecting rod. Three different lengths of connecting rods are available in order to attain the correct piston height. The three different lengths of connecting rods are made by machining the blank small end bearing of each rod at three fixed distances vertically above the centerline of the big end bearing.
The crankshaft has seven main bearing journals. End play is controlled by thrust washers which are located on both sides of the number six main bearing.
The timing case is made of aluminum. The timing gears are stamped with timing marks in order 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 fuel injection pump
The camshaft and the fuel injection pump run at half the rpm of the crankshaft.
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| Illustration 3 | g01360006 |
The Caterpillar fuel injection pump (1) that is installed on the left side of the engine is gear-driven from the timing case. The fuel transfer pump (2) is driven by the fuel injection pump (1) . The fuel transfer pump draws low pressure fuel from the primary fuel filter. The fuel transfer pump delivers the fuel to the secondary filter at a pressure of 400 kPa (58.0160 psi) to 500 kPa (72.5200 psi). The fuel injection pump draws fuel from the secondary filter. The fuel injection pump increases the fuel to a maximum pressure of 130 MPa (18855 psi). The fuel injection pump delivers the fuel to the high pressure manifold (Rail). The fuel injection pump is not serviceable. Adjustments to the pump timing should only be made by personnel that have had the correct training. The engine uses speed sensors and the ECM to control the engine RPM.
For the specifications of the C6.6engine, refer to the Specifications, "Engine Design".