What Is Camming A Car

If you’re looking to significantly boost your car’s horsepower, you’ve likely heard the term. So, what is camming a car? Camming a car involves installing a performance camshaft to alter engine valve timing, significantly increasing power output. It’s a fundamental modification for serious engine builders and enthusiasts seeking maximum performance.

This process changes how your engine breathes. By adjusting when the valves open and close, and for how long, you can let more air and fuel into the cylinders. The result is a powerful increase in torque and horsepower, especially at higher engine speeds.

However, it’s not a simple bolt-on job. It requires careful planning, mechanical skill, and an understanding of how it affects your entire vehicle. This guide will explain everything you need to know about camming your car.

At its core, camming a car means replacing the stock camshaft with a performance-oriented one. The camshaft is a rotating shaft in your engine with lobes (cams) that push against the valves. As it turns, these lobes precisely control the opening and closing of the intake and exhaust valves.

This timing is crucial for engine operation. A stock camshaft is designed for a broad range of conditions, prioritizing smooth idle, good fuel economy, and low emissions. A performance camshaft, often called a “cam,” trades some of that daily drivability for increased power.

It does this by changing three key specifications: lift, duration, and lobe separation angle. These adjustments allow the engine to take in a larger volume of air and fuel mixture and expel exhaust gases more efficiently, which is the foundation of making more power.

Key Components Of A Camshaft Upgrade

Understanding the parts involved is essential before you start. A cam swap is rarely just the camshaft itself. It often requires supporting modifications to handle the new cam’s profile and to realize its full potential.

Camshaft Profile Specifications

The camshaft’s design is defined by its profile. Here are the terms you need to know:

Lift: This is how far the valve opens, measured in millimeters or inches. Higher lift allows more air/fuel into the cylinder.
Duration: This is how long the valve stays open, measured in degrees of crankshaft rotation. Longer duration improves high-RPM power but can hurt low-end torque.
Lobe Separation Angle (LSA): This is the angle, in camshaft degrees, between the centerlines of the intake and exhaust lobes. A narrower LSA increases overlap, boosting top-end power but making the idle rougher.
Overlap: This is the period when both the intake and exhaust valves are open at the same time. Performance cams have more overlap to use exhaust scavenging to pull in fresh air.

Essential Supporting Parts

To install a new cam and ensure it works correctly, you will likely need these components:

Performance Valve Springs: Stock springs may not handle the higher lift and faster valve movement, leading to “float” and engine damage.
Upgraded Pushrods: These may need to be different lengths to maintain proper geometry with the new cam’s base circle.
Timing Chain Set: A new, high-quality timing chain and gears are recommended during the install to ensure precise timing.
Lifters: You must use new lifters matched to the camshaft (flat-tappet or roller) to prevent premature wear.
Engine Tuning: This is absolutely critical. The engine’s computer must be reprogrammed to adjust fuel delivery and spark timing for the new airflow characteristics.

Benefits And Drawbacks Of Camming Your Car

Installing a performance camshaft is a major decision. Weighing the pros and cons will help you determine if it’s the right path for your vehicle and goals.

Advantages Of A Performance Cam

Substantial Power Increase: This is the primary goal. A well-chosen cam can add significant horsepower and torque, often throughout the powerband.
Improved Engine Sound: The altered valve timing creates a distinctive, aggressive “lope” at idle that many enthusiasts desire.
Enhanced Throttle Response: The engine can breathe better, leading to sharper acceleration when you press the pedal.
Higher RPM Potential: With the right supporting parts, a performance cam allows the engine to rev higher and make power at elevated RPMs.

Disadvantages And Considerations

Reduced Low-End Torque: Aggressive cams often sacrifice low-RPM power for high-RPM gains, which can make daily driving feel sluggish.
Poor Idle Quality: The engine may idle rough or stall, especially with a very aggressive cam profile.
Decreased Fuel Economy: The engine tuning required for power typically reduces miles per gallon, sometimes considerably.
Increased Emissions: The car may no longer pass a tailpipe emissions test due to the changed combustion characteristics.
High Cost and Complexity: Between parts, machine shop work, and professional tuning, the total cost can be several thousand dollars.

How To Choose The Right Camshaft

Selecting a cam is about compromise. The right cam for a street-driven muscle car is very different from one destined for a drag-race-only vehicle. You need to define your car’s purpose first.

Consider these factors:

Primary Vehicle Use: Daily driver, weekend cruiser, street/strip racer, or track-only machine?
Engine Specifications: Displacement, compression ratio, cylinder head flow, and induction type (naturally aspirated, supercharged, turbocharged).
Desired Power Band: Do you want strong low-end torque for street driving, or peak high-RPM horsepower for racing?
Transmission and Gearing: Automatic or manual? Rear axle gear ratio? These affect how the power is delivered to the wheels.

It is highly recommended to consult with a reputable camshaft manufacturer or a knowledgeable engine builder. They can recomend a grind that matches your specific combination and goals, ensuring you get the performance you want without excessive drawbacks.

Step-By-Step Guide To The Camming Process

While the exact steps vary by engine, the general process for a typical pushrod V8 engine follows a logical sequence. This is a complex job best suited for experienced mechanics.

Gather Tools and Parts: Ensure you have all necessary tools (wrenches, sockets, torque wrench, harmonic balancer puller, etc.) and the complete camshaft kit with all supporting components.
Disconnect and Drain: Disconnect the battery. Drain the engine coolant and engine oil. Remove the radiator and fan shroud for better access if needed.
Remove Accessory Components: Take off the serpentine belt, water pump, harmonic balancer, and timing chain cover. This exposes the front of the engine and the timing set.
Set Engine to Top Dead Center (TDC): Rotate the crankshaft until the timing marks on the crankshaft and camshaft gears align, indicating cylinder #1 is at TDC on the compression stroke.
Remove the Old Camshaft: Unbolt and remove the timing chain and cam gear. Carefully slide the old camshaft out of the engine block. Be cautious not to damage the cam bearings.
Install the New Camshaft: Liberally coat the new camshaft lobes and journals with a high-quality break-in lubricant. Gently slide it into the block, aligning the dowel pin with the hole in the new cam gear.
Install New Timing Set: Install the new timing chain and gears, ensuring the timing marks are aligned precisely as before. Incorrect timing will prevent the engine from running properly.
Install Supporting Valvetrain Parts: Install the new lifters, pushrods, and valve springs. Double-check that pushrod length is correct for your setup.
Reassemble the Engine: Reinstall the timing cover, harmonic balancer, water pump, and all accessory components. Refill with fresh oil and coolant.
Prime the Oil System: Before starting, use a priming tool on a drill to spin the oil pump. This ensures critical components like the cam and lifters are lubricated immediately on startup.
Break-In Procedure: Start the engine and immediately bring it to 2000-2500 RPM. Hold it steady for 20-30 minutes to properly seat the camshaft and lifters. Vary the RPM slightly during this period. This step is non-negotiable for flat-tappet cams.
Professional Tuning: After break-in, the car must be tuned by a professional using a dynamometer. The air/fuel ratios and spark timing must be optimized for the new camshaft’s airflow.

Common Mistakes To Avoid

Errors during a cam install can lead to poor performance or catastrophic engine failure. Be aware of these common pitfalls.

Skipping the Break-In: Failing to follow the proper break-in procedure can ruin a new flat-tappet camshaft and lifters within minutes.
Incorrect Timing Alignment: If the timing gears are even one tooth off, the engine will not run correctly and valves may contact pistons.
Using Old Lifters on a New Cam: Lifters and cams wear into each other. Old lifters will destroy a new cam’s lobes very quickly.
Neglecting Valve Spring Setup: Installing springs without checking installed height, open pressure, and coil bind can cause valve float and engine damage at high RPM.
Forgetting to Prime the Engine: Starting the engine without pre-lubrication means the cam runs dry for its first critical seconds, causing immediate wear.
Deferring the Tune: Driving the car without a proper tune can cause it to run poorly, overheat, or even cause engine damage from lean or rich conditions.

FAQ About Camming A Car

How much horsepower does a cam add?

The gain varies widely. A mild cam in an otherwise stock engine might add 20-40 horsepower. An aggressive cam in a built engine with supporting mods like heads and intake can add 100+ horsepower. The supporting modifications are key to unlocking the cam’s full potential.

Is camming a car street legal?

The mechanical act of changing the camshaft is generally legal. However, the resulting increase in emissions or the removal of emissions equipment (like EGR) may make the car illegal for street use in areas with strict emissions testing. You should always check your local regulations.

What is the difference between a flat tappet and a roller cam?

Flat tappet cams use lifters with a flat bottom that slides on the cam lobe. They are less expensive but require a meticulous break-in. Roller cams use lifters with a wheel that rolls on the lobe, reducing friction. They offer more aggressive profiles, require less break-in, and are more durable but are more expensive.

Can you cam a car with a stock torque converter?

For automatic transmissions, a very aggressive cam with a rough idle will often require a higher-stall speed torque converter. The stock converter may not allow the engine to get into its power band effectively off the line, negating the cam’s benefits. A mild cam may work fine with the stock converter.

How much does it cost to get a car cammed?

Total costs can range from $1,500 to $5,000 or more. This includes the cam kit ($300-$1,000), gaskets and fluids, potential machine shop work (like checking piston-to-valve clearance), and professional dyno tuning ($500-$1,500). Labor costs for installation are significant if you don’t do it yourself.