What is the Necessity of helical groove on plunger of fuel injection pump?

The helical groove on the plunger of a fuel injection pump is essential for optimizing fuel delivery timing and volume. It allows for a controlled, gradual increase in fuel pressure as the plunger moves, ensuring a smooth injection process. This design helps improve the atomization of fuel, enhancing combustion efficiency and reducing emissions. Additionally, it aids in achieving precise metering of fuel, which is crucial for engine performance and responsiveness.