TUBE AS 3755658 - Caterpillar

Cylinder Block Assembly
The cylinders in the left side of the block form a 65 degree angle with the cylinders in the right side. The main bearing caps are fastened to the block with two bolts for each bearing cap.The cylinder liners can be removed for replacement. The top surface of the block is the seat for the cylinder liner flange. Engine coolant flows around the liners in order to keep the liners cool. Three O-ring seals around the bottom of the liner make a seal between the liner and the cylinder block. A filler band goes under the liner flange. This makes a seal between the top of the liner and the cylinder block. A steel spacer plate is used between the cylinder head and the block. A thin gasket is used between the plate and the block. This thin gasket seals water and oil. A thick gasket of metal and asbestos is used between the plate and the head. This thick gasket seals the combustion gases, water and oil.Cylinder Head Assembly
The cylinder heads are a one-piece cast iron head. Two inlet valves and two exhaust valves, which are controlled by a pushrod valve system, are used for each cylinder. Valve guides without shoulders are pressed into the cylinder heads. The opening for the direct injection adapter is located between the four valves. Series ports are used for both inlet and exhaust valves.The valve lifters can be removed without the removal of the head. The removal can be made because of the size of the pushrod openings through the head.Pistons, Rings And Connecting Rods
The type of pistons that are in the 3408 or 3412 engine depends on the engine's application. These engines will have pistons that are made from aluminum or pistons that are made from steel. The crown of the piston carries all three piston rings. Oil from the piston cooling jets flows through a chamber which is located directly behind the rings. The oil cools the piston which improves the life of the rings. The pistons have three rings which include two compression rings and one oil ring. All the rings are located above the piston pin bore. The oil ring is a standard ring. Oil returns to the crankcase through holes in the oil ring groove. The top ring is a Keystone ring, which is tapered. The intermediate ring will be a Keystone ring for the aluminum piston, or a standard ring that is not tapered for the steel piston.The piston is designed for a direct injection engine. The piston has a cardioid design on the top surface. This piston design helps to improve combustion efficiency. The piston pin is held in place by two snap rings. These snap rings fit in grooves in the pin bore of the piston.The connecting rod has a taper on the pin bore end. This taper gives the rod and the piston more strength in the areas with the most load.Crankshaft
The crankshaft changes the combustion forces in the cylinder