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 1 | 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 C6.6 marine generator set, refer to the Specifications, "Engine Design".
The model views show a typical C6.6 marine generator set. Due to individual applications, your engine may appear different from the illustrations.
Sea Water Cooled MCS
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| Illustration 2 | g01718684 |
(1) Expansion Tank (2) Filler for Engine Coolant (3) Crankcase Breather (4) Air Cleaner (5) Aftercooler (6) Heat Exchanger (7) Duplex Primary Fuel Filters (8) Hand Priming Pump (9) Duplex Secondary Fuel Filters (10) Water Inlet for Auxiliary Water Pump (11) Lower Engine Oil Filler Cap | |
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| Illustration 3 | g01718693 |
(12) Engine Cover (13) Blanket on Exhaust Elbow (14) Rain Cap for Air Cleaner (15) MCS Control Panel (16) Generator Terminal Box (17) Isolator Keyswitch (18) 20 AMP Circuit Breaker (19) 90 AMP Circuit Breaker for the 24 Volt Cold Start (135 AMP for 12 Volt) (20) Electronic Control Module (ECM) (21) Differential Switch for the Primary Fuel Filters (22) Differential Switch for the Secondary Fuel Filters | |
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| Illustration 4 | g01718983 |
(23) Indicator for the Air cleaner (24) Engine Alternator (25) Duplex Oil filters (26) Oil Drain Valve | |
Sea Water Cooled EMCP
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| Illustration 5 | g01621598 |
(1) EMCP Control Panel (2) Isolator Keyswitch (3) Electronic Control Module (ECM) (4) Single Primary Fuel Filter (5) Hand Priming Pump (6) Single Secondary Fuel Filter (7) Coolant Drain on Heat Exchanger | |
A Keel Cooled System
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| Illustration 6 | g01521788 |
(1) Rain Cap for Air Filter (2) Top Oil Filler Cap (3) Water Pump (4) Cover for Belts (5) Oil Gauge (Dipstick) (6) Single Oil Filter (7) Solenoid For Air Starting Motor (8) Air Starting Motor (9) Electric Starting Motor (10) Drains on Exhaust Manifold (11) Terminal Box | |
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| Illustration 7 | g01720373 |
(12) AC Connection (13) Isolatoer Keyswitch (14) Drain on Cylinder Block (15) Alarm Tank Switch (16) Outlet for the Aftercooler (17) Water Inlet for Auxiliary Water Pump (18) Outlet for Keel Cooling | |
Engine with Radiator
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| Illustration 8 | g01720414 |
(1) Filler Cap for Radiator (2) Vent lines for Cooling System (3) Cover on Tube for the Boost Pressure (4) Drain Valve for Radiator (5) Isolator Keyswitch (6) Tube from Aftercooler to the Inlet Manifold (7) Air to air Aftercooler | |