If you’re looking into engine modifications, you’ve probably asked, what does camming a car do? Camming a car involves installing a specialized camshaft to alter engine valve timing, which can significantly increase power and change its performance character. It’s one of the most effective ways to make serious horsepower gains, but it changes how your engine breathes and behaves.
This guide explains everything. We’ll cover how it works, the different types of camshafts, and what you can realistically expect from this major upgrade.
You’ll learn the benefits, the trade-offs, and whether it’s the right move for your vehicle and goals.
What Does Camming A Car Do
At its core, camming a car replaces the stock camshaft with a performance-oriented one. The camshaft is a rotating shaft with egg-shaped lobes that controls the opening and closing of the engine’s valves. These valves let air and fuel in and exhaust gases out.
By changing the shape and timing of these lobes, you alter how long the valves stay open and how far they lift. This directly controls the amount of air and fuel that enters the combustion chamber. More air and fuel, when properly mixed and ignited, means a bigger explosion and more power.
A performance camshaft typically holds the valves open longer and allows them to open wider. This is often described as increasing the engine’s “breathing” capability. It’s like giving your engine a larger, more efficient set of lungs.
The Fundamental Role Of The Camshaft
To understand camming, you must first understand the camshaft’s job. Inside your engine, the pistons move up and down in cylinders. For the engine to run, it needs air and fuel (the intake stroke) and a way to expel the burned exhaust (the exhaust stroke).
The valves are the gates that control this flow. The camshaft is the brain that tells these gates when to open and close, synchronized precisely with the piston’s movement. The stock camshaft is designed by the factory for a broad compromise: decent power, good fuel economy, low emissions, smooth idle, and quiet operation.
A performance camshaft sacrifices some of that daily-driver civility for a greater volume of air flow at higher engine speeds, which is where peak horsepower is made.
Key Camshaft Specifications
When shopping for a cam, you’ll hear three main terms:
- Duration: This is how long, in degrees of crankshaft rotation, the valve stays open. More duration usually means more top-end power, but can hurt low-end torque and idle quality.
- Lift: This is how far the valve physically opens, measured in inches or millimeters. More lift allows more air to flow past the valve.
- Lobe Separation Angle (LSA): This is the angle, in degrees, between the centerlines of the intake and exhaust lobes. A wider LSA gives a smoother idle and broader power band, while a narrower LSA creates a lumpier idle and a more peaky power curve.
Primary Performance Gains And Changes
So, what does installing a camshaft actually achieve? The results are tangible but come with character changes.
The most obvious gain is increased horsepower and torque. Depending on the cam and supporting modifications, gains of 30 to 100+ horsepower are possible. The power band also shifts. A mild cam might boost power across the entire RPM range, while an aggressive “race” cam will move the power higher up, requiring you to rev the engine harder to access it.
The engine’s sound and feel change dramatically. A performance cam often creates a choppy, rumbling idle—that classic muscle car lope. Throttle response usually becomes sharper and more immediate. However, these gains come at a cost to low-speed manners and efficiency.
Common Trade-Offs And Considerations
Camming a car is not a free lunch. You exchange one set of behaviors for another. Be prepared for the following:
- Rougher Idle: The choppy idle is cool but can make the car feel less refined.
- Reduced Low-End Torque: Aggressive cams can make the car feel sluggish below a certain RPM.
- Lower Fuel Economy: Especially at idle and during part-throttle driving.
- Increased Emissions: It may not pass a strict tailpipe emissions test.
- Potential Need for Supporting Mods: To realize the cam’s full potential, you often need upgraded valve springs, pushrods, and possibly heads and an intake.
Types Of Performance Camshafts
Not all cams are created equal. The right choice depends entirely on your goals, budget, and how you use the car. Picking the wrong one can make your car unpleasant to drive.
Street Cams
These are designed for daily-driven or weekend performance cars. They offer a noticeable power increase while maintaining good driveability. Idle is slightly lumpy but stable. Low-end torque loss is minimal, and they usually work well with automatic transmissions and stock converters.
They are a great first step into engine modifications and often don’t require extensive supporting mods, though upgraded valve springs are still a good idea.
Street/Strip Cams
This is a middle-ground category for cars that see both road use and occasional drag strip action. The power gains are more significant, and the idle is noticeably choppy.
You will likely experience a more pronounced loss of vacuum, which can affect power brakes, and may need a higher-stall torque converter for an automatic to get off the line effectively. Supporting modifications like aftermarket cylinder heads become more important here to feed the cam’s appetite for air.
Race Cams
These are for dedicated competition vehicles. They are all about maximum horsepower at high RPM. Idle is very rough and often unstable, low-end torque is poor, and driveability on the street is challenging.
They require major supporting modifications, including high-flow heads, a specialized intake, a high-stall converter or manual transmission, and tuning expertise. Fuel economy and emissions are not considerations.
Roller Vs. Flat Tappet Cams
You’ll also choose between two mechanical designs. Flat tappet cams are the traditional, less expensive option but require a specific break-in procedure with special lubricant. Roller cams use a roller bearing on the lifter, which reduces friction.
This allows for more aggressive lobe profiles, higher RPM capability, and better durability without a stressful break-in. They are more expensive but are considered superior for performance builds.
The Installation Process And Requirements
Camming a car is a significant mechanical undertaking. It’s not a simple bolt-on like an air intake. Understanding the scope of the project will help you plan and budget correctly.
Essential Tools And Preparation
You need a full set of mechanic’s tools, a torque wrench, a way to hold the engine at top dead center (TDC), and a clean, organized workspace. You must also have the correct parts on hand before you start.
This includes the camshaft kit (which often includes lifters), new gaskets for the intake, valve covers, and front timing cover, a tube of assembly lube, and fresh engine oil and filter. It’s also the perfect time to replace the water pump and thermostat if they are older.
Step-By-Step Overview
- Disassembly: Drain the coolant and oil. Remove the radiator, fan, accessory belts, harmonic balancer, and timing cover. You need to remove the intake manifold, valve covers, and rocker arms to access the pushrods and lifters.
- Cam Removal: Rotate the engine to TDC on cylinder one. Unbolt and remove the timing gear or sprocket from the old camshaft. Carefully slide the old cam out of the engine block, being cautious not to damage the bearing surfaces.
- New Cam Installation: Liberally coat the new camshaft lobes and bearing journals with assembly lube. Carefully slide it into the block. Install the new timing gear/sprocket, ensuring the timing marks align perfectly with the crank gear.
- Reassembly: Install new lifters (coated in assembly lube). Reinstall pushrods, rocker arms, and all other components in reverse order of removal with new gaskets. Refill fluids.
- Break-In: This is a critical step. Start the engine and immediately bring it to 2000-2500 RPM for about 20-30 minutes. This seats the lifters to the cam lobes properly. Vary the RPM slightly but do not let it idle. After break-in, change the oil and filter to remove any metal particles.
The Critical Importance Of Professional Tuning
Installing the cam is only half the job. The engine’s computer (ECU) must be recalibrated to match the new camshaft’s characteristics. This is called tuning.
The stock tune expects the stock cam’s airflow and vacuum signals. A performance cam changes these drastically. Without a tune, the car may run poorly, stall, get terrible fuel mileage, or even damage itself.
A professional tuner will adjust the air/fuel ratios, ignition timing, and idle control parameters to optimize performance and driveability. This is not an optional step; it is essential for a successful cam swap.
Supporting Modifications For A Cam Swap
To get the most from your new camshaft and ensure reliability, certain upgrades are highly recommended or even required.
Valvetrain Upgrades
The stock valve springs are not designed for the higher lift and RPM of a performance cam. They can “float” (fail to close the valve properly) at high RPM, causing a loss of power and potentially catastrophic engine damage from piston-to-valve contact.
You must install matching performance valve springs. It’s also wise to upgrade to hardened pushrods and retainers to handle the increased stress. Some cam kits include these components.
Induction And Exhaust Improvements
Think of the engine as an air pump. A performance cam allows it to pump more air. You need to help it by improving airflow in and out.
- Cold Air Intake & Throttle Body: Lets more air into the intake manifold.
- Performance Cylinder Heads: This is one of the best supporting mods. Better heads flow more air, unlocking the cam’s full potential.
- Headers and Exhaust: Frees up the exit path for exhaust gases, reducing backpressure and allowing the engine to breathe easier.
Fuel System And Drivetrain
More power requires more fuel. Your stock fuel pump and injectors may be adequate for a mild cam, but larger projects may require upgrades. Also, consider the drivetrain.
A manual transmission car will be fine, but an automatic with a stock torque converter will feel sluggish with a cam that has poor low-end torque. A higher-stall-speed converter allows the engine to rev into its new power band before the car launches.
Is Camming Your Car Right For You?
This is the big question. Camming a car delivers incredible performance but requires commitment. Ask yourself these questions before proceeding.
What is the primary purpose of the vehicle? A daily driver needs a very mild cam. A weekend toy can handle more aggression. A track-only car can go all out. What is your budget? Remember to factor in the cost of the cam kit, gaskets, tools you might not have, supporting mods (like springs and headers), and the essential professional tune. It often adds up to more than anticipated.
What is your skill level? The installation is complex and mistakes can be expensive. If you’re not confident, hiring a professional is a wise investment. Are you prepared for the compromises? Can you live with a rougher idle, worse gas mileage, and potential cold-start quirks? For many enthusiasts, the trade-off is absolutely worth it for the power and character.
Common Mistakes To Avoid
Learning from others errors can save you time and money. Here are frequent pitfalls:
- Skipping the Tune: This is the number one mistake. The car will not run right.
- Choosing Too Big a Cam: It’s tempting to go for the biggest cam, but an overly aggressive cam in a street car is miserable to drive. Be realistic.
- Neglecting Valve Springs: Using stock springs is asking for engine failure.
- Improper Break-In: Not following the break-in procedure can ruin a new camshaft and lifters in minutes.
- Ignoring Supporting Mods: A cam alone without better breathing (intake/exhaust) won’t make the power you expect.
Frequently Asked Questions
How Much Horsepower Does A Cam Add?
The gain varies widely. A mild street cam in a V8 with basic bolt-ons might add 30-50 horsepower. An aggressive cam in a built engine with heads and intake can add 100+ horsepower. The supporting modifications are just as important as the cam itself.
Can You Cam A Car With An Automatic Transmission?
Yes, absolutely. For mild street cams, the stock torque converter is usually fine. For more aggressive cams, a higher-stall-speed torque converter is recommended to match the engine’s new power band and prevent bogging off the line.
Does Camming A Car Affect Reliability?
If installed and tuned correctly with the proper supporting parts (like valve springs), a camshaft upgrade is very reliable. However, pushing an engine to make more power always adds some stress. Proper maintenance and avoiding constant operation at the redline are key to longevity.
How Much Does It Cost To Cam A Car?
Costs can range from $1,500 to $5,000 or more. A basic cam kit and gaskets might be $500-$800, but professional installation can add $1,000+, and a tune is another $500-$800. Supporting mods like headers, springs, and an intake quickly increase the total. Doing the labor yourself saves money but requires skill.
What Is Cam Timing And How Is It Adjusted?
Cam timing refers to the precise alignment of the camshaft with the crankshaft. It’s set during installation with timing marks. For fine-tuning, adjustable timing gears or “degreeing a cam” allows you to advance or retard the cam’s timing slightly. This can optimize the power band for your specific setup, moving the torque curve lower or higher in the RPM range.