PUMP GP-GEAR 1996105 - Caterpillar

Cylinder Block and Head
The cylinder block for the four cylinder engine has five main bearings that support the crankshaft. The cylinder block for the six cylinder engine has seven main bearings that support the crankshaft. The main bearing caps are fastened to the cylinder block with two bolts per cap.The removal of the oil pan allows access to the following components:
Crankshaft
Main bearing caps
Piston cooling jets
Oil pumpThe compartment for the camshaft is accessible through covers on the left side of the cylinder block. These side covers also support the pushrod lifters. The camshaft is supported by bearings that are pressed into the cylinder block. There are five camshaft bearings for the four cylinder engine and there are seven camshaft bearings for the six cylinder engine.The cylinder head is separated from the cylinder block by a gasket that is made of steel and non-asbestos fiber. Coolant flows out of the cylinder block through gasket openings and into the cylinder head. The gasket also seals the oil supply and the drain passages between the cylinder head and the cylinder block. The air inlet ports are located on the top of the cylinder head. The exhaust ports are located on the right side of the cylinder head. There is one intake and one exhaust valve for each cylinder. Valve guides are pressed into the cylinder head. The fuel injector is located between the two valves. Fuel is injected directly into the cylinders at very high pressure. A system with pushrods and with rocker arms is used in order to control the valves and the fuel injectors.Pistons, Rings, and Connecting Rods
One-piece aluminum pistons are used in most applications. Engines with higher cylinder pressures require two-piece pistons. Refer to the parts manual in order to obtain information about the type of piston that is used in a specific engine.The one-piece aluminum pistons have an iron band for the top two rings. This helps to reduce wear on the compression ring grooves. Oil from the piston cooling jets will spray the underside of the piston. This will cool the piston, which improves the life of the piston and rings. The piston has two compression rings and one oil ring. All of the rings are located above the piston pin bore. The oil ring is of the standard or conventional type. Oil will return to the crankcase through holes that are located in the groove for the oil ring. The design of the compression rings is of the keystone type, which is tapered. The piston groove is also tapered. Too much carbon deposits can cause seizure of the piston rings. This is prevented by the action of the rings in the piston grooves.The two-piece piston consists of an alloy steel crown that is connected to an aluminum skirt by the piston pin. Oil from the piston cooling jets will spray the underside of the piston crown. This will cool the piston, which improves the life of the piston and the rings. The piston rings are located