Vehicle Engines - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 142

internal motor
cooling

lubrication
system

fuel pipes injectors oil pump

fuel
filter

fuel
system

cooling
system

engine
lubrication

injection

seals

fuel pre-cooling
and pre-heating

injection
pump

injection
pressure

external motor
cooling

oil
lines

oil
filter

Fig. 9.4 Cooling and lubricating system of self ignition combustion engines

9.2.2.1 Main Construction Elements

Self ignition engines are usually built in a design with ''in-line'' and ''V'' engine
form [ 25 ]. Friction losses in the construction are shared in the transmission by
32%, in the oil pump by 10%, in the valves by 8%, and in the piston rings by
approximately 50%.
Figure 9.3 presents the main elements of a self ignition engine [ 26 ].
The main construction elements and their influence on fuel combustion and
exhaust gas emissions are presented in Table 9.7 .

9.2.2.2 Main Operation Parameters

Table 9.8 presents the impact of main operation modes on the fuel consumption
and exhaust gas emissions of self ignition engines.
Figure 9.4 shows the common operation of cooling and lubricating system of
self ignition engines.

9.3 Summary and Recommendations: Vehicle
Engine Technology

There are four- and two-stroke engines. The combustion cycle of four-stroke
engines consists of the intake, the compression, the expansion, and the exhaust.
A complete operating cycle of the engine requires two crankshaft revolutions.
Four-stroke engines have one inlet and one outlet valve per cylinder for the gas
exchange.
Key parts of the four-stroke engine are the crankshaft, the connecting rod, one
or more camshafts and the valves.
In a two-stroke engine, two piston strokes and only one crankshaft revolution
are needed for one combustion cycle. The first cycle covers the intake and the
compression; the second cycle does the expansion and moves the exhaust gases