The air intake system consists of the following components:
- Air cleaner or air silencer
- Gas mixer (Series 60 gas engine)
- Charge air cooler
- Throttle actuator (Series 60 gas engine)
- Intake manifold
- Air dryer
The turbocharger supplies air under pressure to the CAC and then to the intake manifold. The air enters the turbocharger after passing through the air cleaner or air silencer. Power to drive the turbocharger is extracted from energy in the engine exhaust gas. The expanding exhaust gases turn a single stage turbocharger wheel, which drives an impeller, thus pressurizing intake air. This charge air is then cooled by an air-to-air or air-to-water (marine engine) intake manifold before flowing into the cylinders for improved combustion efficiency.
On vehicle and industrial engines, charge air cooler (CAC) is mounted ahead of the engine coolant radiator. The pressurized intake charge is routed from the discharge side of the turbocharger, through the CAC to the intake manifold, which directs the air to ports in the cylinder head, through two intake valves per cylinder, and into the cylinder. At the beginning of the compression stroke, each cylinder is filled with clean air.