What is a flywheel ?

Competition Clutch Flywheel
Competition Clutch Flywheel

A flywheel is a rotating mechanical device with a number of teeth on it.  This device stores rotational energy. It reserves rotational energy by resisting changes in rotation speed. Every time your vehicle slows down or comes to a stop it loses momentum.  This device makes up for that by providing continuous energy when the energy source is discontinuous.

Functions of a Flywheel

Engine Start

A flywheel is responsible for the start of your engine. The gear teeth cut into the flywheel’s circumference help start your engine. When you turn your key, a small gear in the engines starter motor called a Bendix mates up to the flywheel.  The Bendix gear/starter motor combination spins the flywheel, which results in turning the crankshaft.  This begins the compression cycle required to start the engine. Once your engine is started the Bendix gear disengages, and your flywheel will spin freely.

Engine Speed Smoothing

Now that the engine has been started, the crankshaft converts the up and down movement of the pistons into rotary motion. The mass of the flywheel applies inertia to keep the engines crankshaft turning between each of the piston firings.  This allows the rotation speed of the crankshaft constant and your engine running smoothly.

Your Pistons are offset from the center of the crankshaft. Your engine also consequently vibrates and wobbles as each pistons fires at a different angle. The weight of your flywheel suppresses the side-to-side motion. This helps stabilize and balance the engine on its mounts and reduce vibration throughout the vehicle.

Stress Reduction

Since they helps stabilize engine movement, it limit stress on other drivetrain components.

ACT Flywheel
ACT Flywheel

Signs of a Bad Flywheel

There are several signs & symptoms that can help you know your due for a new flywheel. A burning smell is a huge sign that your part may need to be replaced. This burning smell is from your clutch being used improperly.  This smell can be caused from a bad component, or from an inexperienced driver.  The smell can be described as a strong pungent, acrid smell. Clutch chatter & clutch slipping are also signs of a bad device. Clutch chatter is when your clutch “skips” along the flywheel’s surface, rather than smoothly engaging. You will feel a stutter or a vibration from clutch chatter.  Clutch slipping occurs is when the clutch is worn out which will eventually lead to a worn out unit. Lastly, you may notice a vibration in your clutch pedal during shifting. These vibrations indicate that the flywheel’s spring mounts have gone bad

Final Words

If you think your vehicle is suffering from a bad flywheel its better to have things checked out before more damage is done. There are a large number of manufacturers who carry flywheels, specifically designed with automotive enthusiast in mind. Some of those brands include ACT, EXEDY, McLeod, and Competition Clutch. Many flywheels developed by these companies are lightweight, and have improved engine response. Overall, a new flywheel is beneficial to anyone looking for better vehicle performance.