How do you know what’s going on with your engine if you don’t know how it works? Here’s a quick brief on what you need to know about the heart of your car, truck, van or SUV.
Your engine is composed of the camshaft, pistons, flywheel, connecting rod, camshaft drive belt, crankshaft and sump. Together, these components allow your engine to convert the heat from burning gas into the force that propels your vehicle forward or backward through a series of chain reactions. Here are the basics in how it all comes together:
The camshaft of your engine is a long rod that has cams along its length. It turns in accordance to the motion of the pistons and the firing of the spark plugs when your engine is running. When the shaft rotates, the cams along its body press spring-loaded valves to open or close, which controls the intake and exhaust for each of your vehicle’s cylinders. Whether your engine has one or more camshafts depends on the shape of your engine and the number of cylinders it contains.
The pistons in your engine are solid metal pieces attached to the connecting rod. Part of the chain reaction that powers the engine is the expansion of gas, which pushes the pistons up and down into and out of a hallow cylinder in the engine block. Once a piston is inside the cylinder, a piston ring, which is attached to the piston, seals the hole shut.
The flywheel, in a manual transmission vehicle, or a flex plate in an automatic transmission car, is a heavy metal disc attached to the crankshaft at the rear of your engine. Its purpose is to store and release energy quickly. It helps start your engine, keep it running smoothly, controls vibrations and helps stabilize balance and can help limit wear and tear on other drivetrain parts.
The connecting rod is designed to be strong enough to handle the stress created from combustion and piston movements. The small end of the rod connects to the piston with help from a piston pin, while the other end is connected to the crankpin journal. These rods convert the up and down movement of the pistons into a rotary motion.
Camshaft Drive Belt
More commonly referred as a timing belt, the camshaft drive belt is notched and drives the camshaft from a sprocket on the end of the crankshaft. The camshaft rotates at half the engine speed and is responsible for the timing of the pistons’ motion. If this belt breaks, falls off or is damaged, the engine will immediately stop working.
The crankshaft is the component responsible for converting the vertical movement of the pistons into a rotational one via the flywheel. These steel shafts also contain counterweights to make the movement of your engine feel smooth. Together, the camshaft and crankshaft start and end the engine cycle with help from the other engine components described above.
The sump is a metal oil pan at the bottom of your engine that collects all the engine oil that isn’t circulating through the engine. There is a tube that sucks up the oil when the engine is running, and returns the unused oil when the engine is off. But the sump is more than just a container; it cools oil as well. When your car is moving, the air flow cools the pan, which cools the oil. Some vehicles include cooling fins to help the sump increase its surface area, which in turn allows more oil to cool at a faster rate.