What is a Piston in Engine and How Does it Work?

A piston is a cylindrical component that moves up and down within the combustion chamber of an internal combustion engine. It plays a vital role in converting fuel combustion into mechanical motion. As the air-fuel mixture ignites, the expanding gases push the piston downward, generating energy. This energy drives the crankshaft and powers the vehicle’s movement.

To ensure that key engine parts like pistons stay protected in the long run, it’s wise to choose a car insurance plan that covers major mechanical damage. Bajaj Allianz General Insurance Company offers motor insurance with extensive coverage, including add-ons for engine protection, giving you peace of mind against unexpected repair costs.

Types of Piston Engine

Pistons come in various shapes, each suited to specific combustion needs:

• Flat Piston: Has a level surface; ideal for standard engines focused on fuel economy and reliability.
• Dish Piston: Concave design helps reduce compression ratio, commonly used in turbocharged engines to prevent knocking.
• Dome Piston: Raised top surface increases compression ratio, delivering higher power in performance engines.

How Do Pistons Work?

Pistons operate through a repeating four-stroke cycle that transforms combustion energy into mechanical force:

• Intake Stroke: The piston moves down, drawing in the air-fuel mixture via the intake valve.
• Compression Stroke: The piston rises, compressing the mixture to prepare it for ignition.
• Power Stroke: The spark plug ignites the mixture, pushing the piston down forcefully—this generates the vehicle's power.
• Exhaust Stroke: The piston moves up again, expelling burnt gases through the exhaust valve.

The piston’s motion transfers to the crankshaft via a connecting rod, creating the rotary motion needed to turn the wheels.

Also Read: What is Engine Protector Cover in Car Insurance?

Additional Piston Functions

• Heat Management: Pistons are made from heat-resistant materials and use piston rings to transfer heat away from the combustion chamber.
• Lubrication: Engine oil coats the piston and cylinder walls, reducing wear and allowing smooth operation under high temperatures.
• Continuous Cycle: The piston performs this cycle continuously while the engine is running—ensuring steady power generation.

Components of Pistons

• Piston Ring: Creates a seal between the piston and the cylinder wall. Prevents oil leaks, ensures compression and dissipates heat. Commonly made of cast iron or steel.
• Piston Skirt: The lower portion of the piston that keeps it aligned and reduces friction during motion.
• Connecting Rod: Links the piston to the crankshaft. Built from tough alloys to handle extreme pressure and stress.
• Connecting Rod Bolt: Secures the rod to the crankshaft, ensuring the piston remains in place during high-speed cycles.
• Piston Bearings: Found at connecting points to reduce friction and absorb engine loads. Essential for smooth, long-lasting engine operation.

Conclusion

Pistons are central to the working of any internal combustion engine. From initiating motion to maintaining engine balance and power delivery, they are critical for performance and efficiency. By understanding how pistons work, drivers can identify early signs of wear, take preventive steps and maintain optimal engine health.

And while your vehicle works hard under the hood, Bajaj Allianz General Insurance Company ensures your peace of mind outside it, with engine protection add-ons, cashless claim settlements and access to 7,200+ cashless garages across India. So, whether it’s regular wear or an unforeseen breakdown, you’re covered.

FAQs

Q1. What materials are pistons made from?

Aluminium alloys are commonly used due to their lightweight and heat resistance.

Q2. Do pistons come in different types?

Yes, including flat, dish and dome pistons—each designed for specific combustion needs.

Q3. What are piston rings?

They seal the piston to the cylinder wall, preventing leaks and assisting in heat and pressure control.

Q4. Can pistons fail?

Yes. Failures can occur due to poor lubrication, high temperatures or prolonged wear—resulting in power loss or engine damage.

Q5. Is engine protection covered by car insurance?

With the right add-ons, Bajaj Allianz General Insurance Company can cover engine damage due to water ingress, oil leakage and more, especially useful for modern vehicles.

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