Chapter 22. -DIESEL AND GASOLINE ENGINES 



UPPER BEARING SHELL 



LOWER BEARING SHELL 



FRAME TO 

 BASE BOLT 



NUMBER 10 

 MAIN BEARING 



^icating oil 

 ;tion outlet 



■|0N SYSTEM 

 OUTLET 



BASE SHIMS 



STUD NUT 



MOATING OIL 

 )ER INLET 



LUBRICATI 

 BYPASS 



LTRATiON 

 SYSTEM INLET 



75.20X 



Figure 22-13.— Engine base. 



the engine. However, in some engines, the oil 

 reservoir may be located at some point relatively 

 remote from the engine; such engines may be re- 

 ferred to as dry sump engines. 



In the engine base shown in figure 22-13, 

 oil sump is an integral part of the base or crank- 

 case, which has functions other than just being 

 an oil reservoir. Many of the smaller engines do 

 not have a separate base or crankcase; instead, 

 they have an oil pan, which is secured directly 

 to the bottom of the block. In most cases, an oil 

 pan serves only as the lower portion of the crank- 

 shaft housing and as the oil reservoir. 



Some engines have flat steel plates attached 

 to each end of the cylinder block. End plates 

 add rigidity to the block and provide a surface 

 to which may be bolted housings for such parts 

 as gears, blowers, pumps, and generators. 



Many engines, especially the larger ones, 

 have access openings in some part of the engine 

 frame. (See fig. 22-11.) These openings permit 

 access to the cylinder liners, main and con- 

 necting rod bearings, injector control shafts. 



and various other internal engine parts. Access 

 doors (sometimes called covers or plates ) for 

 the openings are usually secured with handwheel 

 or nut-operated clamps and are fitted with 

 gaskets to keep dirt and foreign material out of 

 the engine's interior. 



The cylinder assembly completes the struc- 

 tural framework of an engine. As one of the main 

 stationary parts of an engine, the cylinder as- 

 sembly, along with various related working 

 parts, serves to confine and release the gases. 

 For the purpose of this discussion, the cylinder 

 assembly will be considered as consisting of the 

 head, the liner, the studs, and the gasket. (See 

 fig. 22-14.) 



The design of the parts of the cylinder as- 

 sembly varies considerably from one type of 

 engine to another. Regardless of differences in 

 design, however, the basic components of all 

 cylinder assemblies function, along with related 

 moving parts, to provide a gas- and liquid-tight 

 space. 



559 



