What Does Cammed Mean

Overview

In automotive engineering and enthusiast culture, the term “cammed” (or “cammed engine”) describes an internal combustion engine that has been fitted with an aftermarket or performance camshaft. The camshaft controls the opening and closing of the engine’s intake and exhaust valves. A performance camshaft typically features altered lobe profiles—different lift, duration, and lobe separation angle—compared to a stock camshaft. These changes can shift the engine’s power band to higher revolutions per minute (RPM), increase peak horsepower, and alter the engine’s sound and idle characteristics. The process of installing such a camshaft is often referred to as “camming” the engine. While common in hot rodding, muscle cars, and racing applications, a cammed engine may exhibit a rough idle, reduced low-end torque, and decreased fuel efficiency depending on the camshaft specifications.

History / Background

The practice of modifying camshafts dates back to the early days of internal combustion engines. As automobile racing and performance tuning emerged in the early 20th century, enthusiasts and engineers recognized that altering valve timing could significantly affect engine output. In the 1950s and 1960s, the rise of the American muscle car era popularized aftermarket camshafts as a relatively inexpensive way to increase horsepower. Companies such as Crane Cams, Comp Cams, and Iskenderian Racing Cams became well-known for producing performance camshafts for both street and track use. The term “cammed” entered common usage among gearheads to describe vehicles that had undergone this modification. Over decades, advances in computer-aided design and manufacturing have allowed for highly specialized cam profiles tailored to specific engine configurations and intended uses—from mild street performance to extreme drag racing or circle track applications.

Importance and Impact

The impact of camming an engine extends beyond raw power gains. It has influenced automotive culture, aftermarket industries, and engine design philosophies. For many enthusiasts, a cammed engine is a hallmark of a built or modified vehicle, often associated with a distinctive loping idle sound that announces the car’s performance intent. The availability of camshaft upgrades has enabled hobbyists to personalize their vehicles’ power delivery and character without swapping the entire engine. On a broader scale, the camshaft aftermarket supports a multi-billion-dollar industry of parts, tools, and services. However, the trade-offs—reduced drivability at low speeds, increased emissions in some cases, and potential need for supporting modifications (e.g., upgraded valvetrain, fuel system, tuning)—mean that camming is not a universal upgrade. Its significance lies in being a foundational modification for those seeking maximum naturally aspirated performance or specific engine behavior.

Why It Matters

Understanding what “cammed” means is relevant for anyone interested in automotive performance, engine building, or car culture. For buyers of used performance cars, recognizing a cammed engine can indicate a vehicle that has been modified, which may affect reliability, insurance, and legality (e.g., emissions compliance). For DIY mechanics and tuners, knowledge of camshaft selection and its consequences is essential to achieve desired results without compromising the engine’s longevity or daily usability. Additionally, the term appears frequently in online forums, classified ads, and enthusiast discussions, making it a key piece of automotive vocabulary. As modern engines increasingly use variable valve timing and electronically controlled camshafts, the traditional fixed-cam modification remains relevant for older platforms and dedicated race builds.

Common Misconceptions