C-10 and C-12 Truck Engines Caterpillar


Basic Engine

Usage:

C-10 MBJ

Cylinder Block

The cylinder block is a unique design with a deep counterbore that supports the cylinder liner. The cylinder block also forms the coolant jacket. Two oil manifolds are provided in the cylinder block for engine lubrication. The manifold on the lower right side of the cylinder block provides oil to the following components:

  • Piston cooling jets

  • Crankshaft bearings

  • Oil filter base

The manifold on the upper left side of the cylinder block provides oil to the following components:

  • Camshaft bearings

  • Valve mechanism

The manifold on the right supplies oil to the manifold on the left. The oil travels through the cut above the number one main bearing and the cut above the number four main bearing.




Illustration 1g00762739

Cylinder liners (1) are seated on a ridge (4) in the middle of the cylinder wall between the crankcase and the coolant jacket. The ridge is created by a counterbore in the cylinder block. The cylinder liners have a lip (2) which rests on the ridge. The seals of the coolant jacket are located in the upper regions and middle regions of the cylinder liners. The lower barrier uses a D-ring seal (3) that is located above the seating surface of the cylinder liner. The upper barrier is the head gasket which is above the coolant jacket.

The cylinder block has seven main bearings in order to support the crankshaft. The main bearing caps are fastened to the cylinder block with two bolts per cap.

Pistons, Rings, and Connecting Rods




Illustration 2g00762765

The piston is a two-piece articulated piston. The piston has a forged steel crown (5) and a cast aluminum skirt (6). Both parts are retained by the piston pin to the small end of the connecting rod.

The pistons have three rings:

  • Compression ring

  • Intermediate ring

  • Oil ring

Rings (2) are located in grooves in steel crown (5). The rings seal the crankcase from the combustion gases and the rings also provide control of the engine oil. The design of compression ring (1) is a barrel face with a plasma face coating. The design of intermediate ring (3) is a tapered shape and a chrome finish. Oil ring (4) is double railed with a coil spring expander. The oil ring has a ground profile and a chrome finish.




Illustration 3g00762786

Connecting rod (8) is a conventional design. The cap is fastened to the shank by two bolts (9) that are threaded into the shank. Each side of the small end of the connecting rod (7) is machined at an angle of 12 degrees in order to fit within the piston cavity. This allows a larger surface area on the piston, and connecting rod in order to minimize bearing load.

Crankshaft

The crankshaft converts the linear motion of the pistons into rotational motion. The crankshaft drives a group of gears (front gear train) on the front of the engine. The front gear train provides power for the following components:

  • Camshaft

  • Water pump

  • Engine oil pump

  • Air compressor

  • Fuel transfer pump

  • Accessory drive

The crankshaft is held in place by seven main bearings. The oil holes and the oil grooves in the shell of the upper bearing supply oil to the connecting rod bearings. The oil holes for the connecting rod bearings are located at the following main bearing journals: 2, 3, 5 and 6.

Hydrodynamic seals are used at both ends of the crankshaft to control oil leakage. The hydrodynamic grooves in the seal lip move lubrication oil back into the crankcase as the crankshaft turns. The front seal is located in the front housing. The rear seal is installed in the flywheel housing.

Camshaft




Illustration 4g00762808

The camshaft has three lobes at each cylinder in order to operate the unit injector, the exhaust valves, and the inlet valves. Seven bearings support the camshaft. The camshaft is driven by an idler gear that is turned by the crankshaft in the front gear train. Each bearing journal is lubricated from the oil manifold in the cylinder block. A thrust pin that is located at the rear of the block positions the camshaft through a circumferential groove. The groove is machined at the rear of the camshaft. Timing of the camshaft is accomplished by aligning marks on the crankshaft gear, idler gear, and camshaft gear with each other.

The injector lobe on the camshaft has a modified profile. The modified profile produces multiple injections.

Vibration Damper

The force from combustion in the cylinders and from driveline components will cause the crankshaft to twist. This is called torsional vibration. If the vibration is too great, the crankshaft will be damaged. Driveline components can excite torsional stress. This stress will cause damage to components. The vibration damper limits the torsional vibrations to an acceptable amount in order to prevent damage to the crankshaft.

The viscous vibration damper is installed on the front of the crankshaft. The viscous vibration damper has a weight in a case. The space between the weight and the case is filled with a viscous fluid. The weight moves in the case in order to limit the torsional vibration.

Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.