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How Much HP Does a Cam Add? [Here’s What You Can Expect]

How Much HP Does a Cam Add? [Here’s What You Can Expect]

All internal combustion engines have a camshaft. However, a lot of people replace them with aftermarket models. 

Replacing them with an aftermarket part can help boost the power of your engine. But will replacing your camshaft add horsepower? And if so, how much?

The size of the boost depends on your engine’s initial power. Generally, you can expect a camshaft to add 10 to 20 HP. You can add even more power by upgrading the vehicle’s intake and exhaust as well. 

A stage 2 cam usually adds about 25% to your engine’s power. And, a stage 3 model can add as much as 40% to it. Each model has its own benefits and downsides. 

So, everyone has to decide whether it’s a worthwhile upgrade themselves. 

What Does A Camshaft Do?

What does a camshaft do when it’s put in your engine? 

If you know how engines work usually, understanding how cams work isn’t hard. They’ve got to make sure the valves stay open when fuel gets injected into the pistons. 

Keeping them open longer allows more fuel to enter the combustion chamber. 

Your engine’s camshaft actually connects to another part called the crankshaft. These two parts work together while your engine is on. They’re both important to the engine’s timing chain.

The cam works by converting rotational energy into linear energy. It does this by resting on a moving piece of metal.

This metal lifts the cam as it rotates around in a circle. When the metal is at the top of its rotation, the cam opens a valve. 

That’s when fuel enters the engine, and we call this the intake stage. After fuel mixes with air, it’s put under pressure in the pistons. 

Each of the pistons has several cams at the top.

They’ll open them when they’re at the apex of their rotation. At the same time, they’re working in opposition to the engine’s crankshafts. 

The crankshaft and camshaft must work together for the engine to function. Otherwise, you’ll have an issue with its timing chain, causing it to malfunction. 

Your engine might have 2 cams per piston, or it can have 4. Most of the time, you’ll have the same number of cams for each of them. 

So, you’d have to replace them all if you’re trying to upgrade the engine. 

Why a Camshaft Can Increase Horse Power

Now, we understand how the cam works inside the engine. That still doesn’t tell us why upgrading them can boost an engine’s power, though. 

We can see a boost in an engine’s power after replacing its cam because of its fuel mixture. Larger cams manage to hold the engine’s valves open longer when they’re pushed up. 

The longer your valves stay open, the more fuel can enter the combustion chamber. 

Adding more fuel increases the strength of combustion, increasing your engine’s HP. 

One of the best things about new cams is they don’t mess up your engine’s timing. A well-designed one keeps the valves open longer without changing anything else.

That’s how they’re able to boost your engine’s power and efficiency. 

There’s only so much power added by replacing the camshaft, though. Once you’ve put new ones in, they’ll only affect power a little.

That’s because they’re limited by the engine’s fuel injectors. 

Your cams can hold the valves open longer, but they’ll still need fuel from the injectors. You can further boost your engine’s power by getting new injectors, too.

If you’re going to do that, you may as well get new valves. 

Combining a new cam with injectors could make a huge difference. The cams would open the valves longer. 

Plus, new injectors would push more fuel into the chamber while it’s open. 

Usually, adding a new cam isn’t the most cost-effective way to boost an engine’s power. You’ll have to replace more than just that part to really notice a difference. 

Does the Camshaft Stage Affect Power Changes?

Camshafts are available in multiple stages. Their staging describes how they work in the engine. Most of them are stage 1, but not all of them are. 

A stage 1 cam is only going to add about 10 HP to your engine. At best, you’ll see an increase of nearly 20 HP if you add a stage 1 cam. 

You can see a much larger boost by adding a stage 2 cam. 

These require an upgraded intake and exhaust, too. Once you’ve installed them, you’ll have to reprogram the car’s ECU. If you’ve done all that, you might see a 25% boost in HP. 

A stage 3 cam can add even more horsepower than a stage 2 one. 

To add one, you’ve got to do all the modifications from stages 1 and 2. Then, you’ll have to complete a big bore of the engine. That’s when you’re able to finish adding a stage 3 cam to it. 

You can also change the cam’s timing to see how it’ll affect your car’s performance. 

Speeding them up usually boosts power when you’re at low RPMs. Slower cams tend to boost power more when you’re at the high end of things. 

Camshaft Replacement Cost

The amount it costs to replace a cam depends on your vehicle. You should expect it to run about $200 to $500 per cam.

Of course, you’ll have to replace multiple if you’re upgrading the whole engine. 

You can save a little by upgrading them yourself. However, you’ve got to make sure you’ll have enough time to complete everything. It’s not a difficult project, but it takes a while. 

We’d suggest calling a few shops nearby to ask them how much they’d charge you to upgrade yours. 

A lot of them are willing to offer discounts when you’re upgrading all the cams at once. So, you might not spend as much if you’re getting them all done at the same time. 

Is It Worth Upgrading the Camshaft?

You’ll spend more money upgrading your cams than you’d spend on other projects. But, you’ll only notice a small boost to your engine’s power. 

That’s why we’d suggest doing another project if you’re only interested in power. Even replacing the fuel injectors could make a bigger difference. 

There are a few reasons it may be worthwhile to replace the cams, though. If you enjoy how engines sound when they’ve got large cams, it’d be worthwhile. 

A set of large cams lowers the engine’s pitch, making them sound deeper. We’ve always loved how it sounds when a truck has large cams in its engine. 

So, if you’re also a fan, then you’d love this project. 

Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!