One of the most hardworking parts inside a car engine, the piston is responsible for powering up a vehicle via its pumping motion. It basically transfers force from the gas inside the cylinder to the crankshaft with the help of a piston rod. Because it constantly moves once the engine is turned on, it needs plenty of lubricating oil to lessen friction. It's also usually made of aluminum alloy so that it can withstand regular exposure to plenty of heat, friction, and pounding force.
How pistons work?
Four main processes are involved whenever pistons put a car in motion. First is the air and fuel intake. As the pistons begin to move, just the right amount of air and fuel are mixed together and injected into the cylinder. As the pistons move up, they compress the air and fuel inside the cylinder to maximize the mixture's explosiveness. Once the pistons hit the cylinder's top, the spark plug ignites the fuel to create combustion. The force that comes with this combustion is what pushes the pistons back to the cylinder's bottom. Now as the pistons are pushed downwards, the combustion's residue is sucked out through an exhaust outlet. These four processes are repeated as the pistons move up and down real fast.
Why does a piston break down?
Because of the pistons' task, it's designed to withstand exposure to damaging elements. However, bad maintenance habits and time can cause damage to these parts. Here's a list of common car problems that can eventually damage the pistons:
- An air-and-fuel mixture that's too lean . If the mixture becomes too lean, the engine won't ignite properly. And because an excessively lean air-and-fuel ratio burns hotter, it can quickly overheat pistons and valves.
- Too much clearance between the cast pistons and the cylinder bore . A large gap between the pistons and the bore will result into fractured skirts.
- Using the wrong motor oil . Pumping the engine with motor oil that's too thick will easily shorten the life of the pistons because oil with high viscosity doesn't extract engine heat properly as compared to oil with low viscosity.
- Installing poorly built retainers, split locks, and valve springs . Retainers, valve springs, and split locks that aren't worth their salt will easily wear out, which could easily lead to a collision between the valve and a piston.
- Excessively hot engine coolant . A coolant that's too hot can remove the cylinder tension from the piston rings, causing them to malfunction.
- Attaching the wrong size of valve relief . Using the wrong size of valve relief can spell trouble for your car's pistons. This is why it's best to buy a valve relief after confirming the actual valve sizes.
- Using fuel without enough octane in it . An excessively low-octane fuel isn't really good for your pistons' health if you're using a high-compression engine since this fuel type can fracture or burn cast pistons. And once a piston is burned out or fractured, you'll have to replace it, which will take a lot of your time and money.