One of an engine’s most crucial components is its pistons, they are the mechanisms that store the power of the engine. The cylinder block contains the pistons. An engine’s cylinder count can change. Based on the cylinder bore of the specific engine they are being fitted in, pistons are available in a variety of materials and sizes. It’s crucial to use the right pistons to achieve the right fit in your engine block and keep the right compression ratio. The engine has a piston ring which gives no space for energy escape.
To convert thermal energy into mechanical work and vice versa, the pistons are helpful. To continue the heat-converting process, a piston follows a cyclical procedure. The air-fuel mixture expands and compresses as it goes up and down inside the cylinder. Because of this, an internal combustion engine must have a piston.
Piston’s heat converting process
- Providing heat to the gas inside the cylinder for the useful work
- Removing heat from the cylinder lowers the pressure and makes it easier to compress the gas.
- Applying work to the piston when it’s in its initial state, ready to perform the cycle again.
Functions of a piston
- The primary job of the piston is to transmit the force of a small gas explosion to the crankshaft. This gives a flywheel rotating momentum.
- It moves forward so that gases can be compressed and an explosion can occur for backward movement.
- Piston pin which is located inside the piston prevents the gas inside the chamber from escaping.
- Thanks to a connecting rod that is fastened to the bottom of the piston. It helps in mechanical work to transfer.
- During the combustion cycle, pistons assist in moving the air-fuel mixture.
- Pistons aid the control of oil flow in the cylinder walls using the oil control ring.
How does a piston work?
The piston in the cylinder goes up and down when the engine is running. The piston slows down as it approaches the turning point before abruptly resuming its acceleration. The piston is subjected to inertia forces as a result. This creates the piston force, which is transmitted to the connecting rod and crankshaft when combined with the forces produced by the gas pressure. Only at the top and lower turning locations are the connecting rods perfectly vertical. The piston is forced up against the side of the cylinder wall by the connecting rod’s tilt. As a result of the piston force and the angle between the piston crown and connecting rod axis, this force’s magnitude and direction are continually changing during the combustion cyclePiston rings are an integral part of pistons. Concerning the crankcase, they seal the combustion and operating chambers. They also remove oil from cylinder walls, reducing oil usage. Piston rings also transfer the heat that the piston absorbs during combustion to the cooled running surface of the cylinder liner.
The very first material utilised to make pistons were cast iron. Modern engines, however, benefit from lighter materials for balancing. The combustion temperatures of the engine must be adequate to withstand good pistons. For obtaining such qualities, alloys like aluminium are specifically employed.
Aluminium alloys are cast into pistons throughout the manufacturing process. Some of the pistons used in racing vehicles need to be stronger and have a longer fatigue life, hence they are forged.
Because they do not depend on the size and architecture of the readily available forgings, billet pistons are also employed in racing engines where the design is more flexible. Even though it rarely appears to the unaided eye.
Things that go wrong with pistons:
1. Timing belt snapped
The timing belt maintains the pistons and valves moving in a precisely balanced manner, but if it breaks, the pistons and valves may collide and suffer severe damage. It’s crucial to replace the timing belt following the recommendations of the vehicle’s manufacturer.
2. Worn piston rings
Over time, piston rings begin to wear, and the airtight seal between the piston and cylinder is compromised. As a result, oil enters the firing chamber from the crankcase through the piston. White smoke emanating from the exhaust pipe and a decline in engine oil level are signs of this.
3. Piston slap
If the noise persists after the engine has reached operating temperature, the piston or cylinder may be worn. Too much space between the piston and the cylinder wall will result in a noisy piston.
How to prevent damage to your pistons?
Making sure the rest of the automobile is in the top functional condition is the greatest method to guarantee your pistons are operating at maximum efficiency. Therefore, ensure you are using the proper oil for your engine and get the engine oil and filter changed at the prescribed intervals.