DIESEL ENGINES
DOE-HDBK-1018/1-93
Diesel Engine Fundamentals
The Cylinder Block
The cylinder block, as shown in Figure 4, is generally a single unit made from cast iron.
In a liquid-cooled diesel, the block also provides the structure and rigid frame for the
engine's cylinders, water coolant and oil passages, and support for the crankshaft and
camshaft bearings.
Figure 4 The Cylinder Block
Crankcase and Oil Pan
The crankcase is usually located on the bottom of the cylinder block. The crankcase is
defined as the area around the crankshaft and crankshaft bearings. This area encloses the
rotating crankshaft and crankshaft counter weights and directs returning oil into the oil
pan. The oil pan is located at the bottom of the crankcase as shown in Figure 2 and
Figure 3. The oil pan collects and stores the engine's supply of lubricating oil. Large
diesel engines may have the oil pan divided into several separate pans.
Cylinder Sleeve or Bore
Diesel engines use one of two types of cylinders. In one type, each cylinder is simply
machined or bored into the block casting, making the block and cylinders an integral
part. In the second type, a machined steel sleeve is pressed into the block casting to form
the cylinder. Figure 2 and Figure 3 provide examples of sleeved diesel engines. With
either method, the cylinder sleeve or bore provides the engine with the cylindrical
structure needed to confine the combustion gasses and to act as a guide for the engine's
pistons.
ME-01
Rev. 0
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