When it comes to modding your boat or vehicle for increased performance, one of the most popular upgrades is installing a high-performance camshaft. A camshaft controls the opening and closing of the engine’s valves, which in turn affects the amount of air and fuel that enters the combustion chamber. By installing a cam with increased duration, you can potentially increase horsepower and torque. However, there is a point where too much cam duration can have negative effects on engine performance and reliability.
What is Duration Anyway?
Cam duration refers to the amount of time that the intake and exhaust valves are open during the engine’s combustion cycle. A longer duration camshaft keeps the valves open for a greater amount of time, allowing more air and fuel to enter the combustion chamber and improving engine performance. However, there are a few key factors to consider when determining how much cam duration is too much for your specific vehicle.
Defining your Engine Speed
One of the main factors to consider when choosing a camshaft with increased duration is the engine’s rpm range. A camshaft with a longer duration is typically optimized for higher engine speeds, as it allows the valves to open and close more quickly to accommodate increased air and fuel flow. If your engine is not able to rev high enough to take advantage of the cam’s increased duration, you may experience a decrease in performance and responsiveness.
Putting the Squeeze on – Choosing a Compression Ratio
Another factor to consider is the engine’s compression ratio. A higher duration camshaft typically requires a higher compression ratio to achieve optimal performance. If your engine’s compression ratio is too low, you may experience a loss of power and efficiency with a camshaft that has too much duration. It is important to consider both the camshaft’s duration and the engine’s compression ratio when selecting a camshaft for your vehicle.
In addition to engine speed and compression ratio, it is important to consider the vehicle’s intended use when selecting a camshaft with increased duration. A camshaft with too much duration can be overly aggressive for a daily driver, leading to poor idle quality, decreased fuel efficiency, and potential drivability issues. On the other hand, a camshaft with too little duration may not provide the performance gains you are looking for in a high-performance application.
Other Things that Spring to Mind when Picking a Cam
It is also important to consider the valve springs and other valvetrain components when installing a camshaft with increased duration. Because longer duration camshafts typically have higher lift, a longer duration camshaft can place higher stress on the valvetrain components, which can lead to premature wear and potential failure if not properly matched with the appropriate components. It is important to ensure that the valve springs, lifters, and other valvetrain components are able to accommodate the increased stress of a camshaft with higher duration. We can help with this! Click here to find out how!
Conclusion
Overall, there is no one-size-fits-all answer to how much cam duration is too much for your specific vehicle. It is important to consider a variety of factors, including engine speed, compression ratio, your performance goals, and your mating components. With these chosen well, you can obtain the performance you’re looking for with the durability you need.
