The Basics of Engine Camshafts

A camshaft is a crucial component that’s essential for an engine to function. It’s comprised of two main parts—the shaft and the cams. With each rotation, the egg-shaped lobes (or cams) synchronize the valve openings within the crankshaft gear.

In this blog, we’ll go over the basics on engine camshafts.

How Camshafts Work

Since there’s a specific order to how cylinders fire, each individual lobe is designed for the cylinder’s exhaust or intake valve. If the cam covers were to be removed while the engine is still running, you’d see the valve heads getting hit like a high-speed game of whack-a-mole. The cam acts like the mechanical brain of the engine—everything depends on it.

The size and shape of the lobes determine the duration for which the valves remain open, as well as the speed of their rotation. This means that even minor changes to the cam will significantly alter the amount of air that’s allowed to enter and exit the engine.

Selecting the best cam depends on a number of variables. For instance, new cars come with two—or maybe even four—cams making the timing aspect highly complex. More than one cam results in expensive parts as well as additional hours of labor. Unless you have the right tools and manpower at your disposal, swapping cams can prove to be an arduous task. If you feel as though carrying out this task is too difficult, it’s best to contact the professionals.

Selection Factors

The main selection factors for camshafts are their duration and lift. Duration determines how long the valve remains open, whereas lift determines the degree to which the valve opens. The higher the lift, the more the amount of air that’s permitted to enter and exit the engine.

It also comes down to your driving style; greater torque at lower RPM usually ends up sacrificing top-end performance. On the other hand, a higher RPM camshaft will make city driving much more uncomfortable. It’s wise to go online and read reviews to see what factors other users considered during the selection process.


Unfortunately, the number of and access to computer numerical control machines (CNC) has increased, which has led to an increase in the number of amateur suppliers in the market. This has resulted in cheap cams or cam remanufacturing services that end up damaging car engines.

ATL Diesel is a quality diesel engine parts suppliers that also offer remanufacturing camshaft service. They’ve been in the industry for over five decades and have an unmatched success rate. Contact us today for more information.