ABSTRACT
Most countries have laws that control the amounts of the harmful gases (emissions) that are permitted, and engine air and exhaust systems are designed to comply with these laws.
Figure 11.3 shows themain features of a petrol (spark ignition) engine air supply system. Our main concern, at the
moment, is the air cleaner and the intake pipe (induction tract) leading to the combustion chamber. The blow-by filter and the positive crankcase ventilation (PCV) system are part of the emission control system.
