Cylinder Block And Liners
A steel spacer plate is used between the cylinder head and the block to eliminate liner counterbore and to provide maximum liner flange support area (the liner flange sits directly on the cylinder block).
Engine coolant flows around the liners to cool them. Three O-ring seals at the bottom and a filler band at the top of each cylinder liner form a seal between the liner and the cylinder block.
Pistons, Rings And Connecting Rods
The piston has three rings; two compression and one oil ring. All rings are located above the piston pin bore. The two compression rings seat in an iron band which is cast into the piston. Pistons in earlier engines used compression rings with straight sides. Pistons in later engines use compression rings which are of the KEYSTONE type. KEYSTONE rings have a tapered shape and the movement of the rings in the piston groove (also of tapered shape) results in a constantly changing clearance (scrubbing action) between the ring and the groove. This action results in a reduction of carbon deposit and possible sticking of rings.
The oil ring is a standard (conventional) type and is spring loaded. Holes in the oil ring groove provide for the return of oil to the crankcase.
The full-floating piston pin is held in place by two snap rings which fit in grooves in the pin bore.
Piston cooling jets, located on the cylinder block main bearing supports, throw oil to cool and give lubrication to the piston components and cylinder walls.
The crankshaft changes the combustion forces in the cylinders into usable rotating torque which powers the machine. There is a timing gear at each end of the crankshaft which drives the respective timing gears.
The bearing surfaces on the crankshaft get oil for lubrication through passages drilled in the crankshaft.
The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that cause damage.
CROSS SECTION OF TYPICAL RUBBER VIBRATION DAMPER
1. Flywheel ring. 2. Rubber ring. 3. Inner hub.
The rubber damper is made of a flywheel ring (1) connected to an inner hub (3) by a rubber ring (2). The rubber makes a flexible coupling between the flywheel ring and the inner hub.
The viscous damper is made of a weight (1) in a metal case (3). The small space (2) between the case and weight is filled with a thick fluid. The fluid permits the weight to move in the case to cause a reduction of vibrations of the crankshaft.
CROSS SECTION OF A TYPICAL VISCOUS VIBRATION DAMPER
1. Solid cast iron weight. 2. Space between weight and case. 3. Case.