Choosing the right cam for your power requirements can be confusing for most people including experienced tuners. Most do not have the time available for hundreds of hours of track testing or access to a dynamometer. Even if you do have a dyno the results can be difficult to sort out. With this article we hope to provide you with a basic overview that will allow you to choose the correct Hot Cam for your requirements.
Think of the cam as the entrance and exit doors to your combustion chamber. Power is made in the combustion chamber; the cam just opens each of the doors at a selected time and holds them open for a specified length of time. Engine performance is produced by a multitude of components and functions that work together to hopefully produce the largest explosion possible in the combustion chamber and forcing the piston down with great force. The cam can increase or decrease the power output of the engine and move the RPM where peak torque is produced. When the proper cam is chosen it allows the other engine functions to supply the combustion chamber with the components required for the “explosion” that forces the piston down. The cam can maximize the efficiency of a set of given engine components and settings, increasing power output by 5-10% on many stock engines.
Good Cam Design
Your first thought would be that a cam can be made that will open a valve to any lift and duration for any engine. Once you know a small amount about cam design you will realize that this is not possible. There are many engine components that limit how quickly and how far the valve can be opened. Hot Cams are designed to produce reliable performance. Our advanced computer design techniques analyze the stresses that are applied to valves, springs, followers, etc. to insure that no component is over-stressed. We test all cams to verify performance and reliability at our facility in Urbandale, Iowa.
Yes, it is possible to push the limits of valve train reliability beyond our standards for our cataloged cams and get a small increase in power for a racing team application. However this power increase comes at the expense of a decrease in lifetime of valves, springs, followers, and other components. Be cautious of cams that claim to make large amounts of power from companies that do not have an internal testing program. (Handing out free cams at the local MX track does not qualify as a reliable testing procedure. Or worse yet, selling untested cams and waiting for customer complaints.).