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When is fuel injected into a diesel engine cylinder?
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diesel engine
Diesel engine equipped with a precombustion chamber.
In a diesel engine, fuel is introduced into the cylinder as the piston approaches top dead centre of its stroke.1
Precise control of this timing is critical to engine performance, as the entire combustion process is governed by when the fuel is injected. Injection must begin at the correct piston position, typically measured by the crank angle. Initially, the fuel burns in a nearly constant-volume process while the piston is near top dead centre; as the piston moves away from this position, fuel injection continues, and the combustion process transitions into a nearly constant-pressure process.1