PRINCIPLES OF NAVAL ENGINEERING 



CYLINDER 

 HEAD STUD 



CYLINDER 

 LINER BORE 



75.14X 



Figure 22-11.— Cylinder block with in-line cylinder arrangement. 



SCAVENGING AIR 

 CHAMBERS 



UPPER DECKPLATE 



TRANSVERSE FRAME MEMBER 



CAMSHAFT POCKET 



LOWER DECKPLATE 



75.16 

 Figure 22-12,— An example of a V-type 

 cylinder block construction. 



to complete the housing. In others the crankcase 

 is a separate part and is bolted to the block. 



In large engines of early design, the sup- 

 port for the main bearings was provided by 

 a bedplate. The bedplate was bolted to the 

 crankcase and an oil pan was bolted to the 

 bedplate when a separate oil pan was used. 

 In some large engines of more modern design 

 the support for main bearings is provided by a 

 part called the base. Figure 22-13 illustrates 

 such a base, which is used with the block shown 

 in figure 22-11. This type base serves as a 

 combination bedplate and oil plan. This base 

 requires the engine block to complete the frame 

 for the main engine bearings. Some crankcases 

 are designed so that the crankshaft and the main 

 bearings are mounted and secured completely 

 within the crankcase. 



Since lubrication is essential for proper 

 engine operation, a reservoir for collecting and 

 holding the engine's lubricating oil is a necessary 

 part of the engine structure. The reservoir may 

 be called a sump or an oil pan , depending upon 

 its design, and is usually attached directly to 



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