【正文】 thus, for a given cylinder block longer stroke, giving greater engine displacement and power, requires a shorter connecting rod (or a piston with smaller pression height), resulting in accelerated cylinder wear. Compound rods Manycylinder multibank engines such as a V12 layout have little space available for that many connecting rod journals on a limited length of crankshaft. This is a difficult promise to solve and its consequence has often led to engines being regarded as failures. The simplest solution, almost universal in road car engines, is to use simple rods. This requires the rod bearings to be narrower, increasing bearing load and the risk of failure in a highperformance engine. This also means the opposing cylinders are not exactly in line with each other. In certain types of engine, the master rod carries one or more ring pins to which are bolted the much smaller big ends of slave rods on other cylinders. Radial engines typically have a master rod for one cylinder and slave rods for all the other cylinders in the same bank. Certain designs of V engines use a master/slave rod for each pair of opposite cylinders. A drawback of this is that the stroke of the subsidiary rod is slightly shorter than the master, which increases vibration in a vee engine. The usual solution for highperformance aeroengines is a forked connecting rod. One rod is split in two at the big end and the other is thinned to fit into this fork. The journal is still shared between cylinders. The RollsRoyce Merlin used this style. Crank linkage of the type and characteristics The use of the internal bustion engine crank linkage of many types, according to kinematics perspective can be divided into three categories, namely: Heart crank linkage, the eccentric crank linkage and the main vicelink crank linkage. Centre crank linkage is characterized by the cylinder through the centerline of the crankshaft rotation centre and perpendicular to the axis of rotation of the crank. This type of linkage in the internal bustion engine crank in the most widely used. The singleengine general, tied for linkage with the use of the Vshaped chaxing link the internal bustion engine, and the home of the piston internal bustion engine crank linkage fall into this category. Eccentric crank linkage is characterized by vertical cylinder centerline of the crankshaft rotating in the center, but not by crankshaft rotary centre, the cylinder centerline distance between the crankshaft with a rotary axis offset e. This crank linkage institutions can reduce the swelling in the itinerary of the piston and cylinder intramural largest lateral pressure so that the pistons in the expansion programme and pressure reduction programme in the cylinder wall at the role of lateral pressure on both sides of the relatively uniform size. Vicelink the main crank linkage is characterized by: the internal bustion engine cylinder with a main link, the other out vi