Camshafts are one of the most common modifications made to a car’s engine. And while there is no one-size-fits-all answer as to whether or not a camshaft increase horsepower, there are some general consensus points that tend to hold true.
In this article, we’ll explore why camshafts are installed, and whether or not they actually do increase horsepower.
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Does a Camshaft Increase Horsepower?
A lot of people are wondering if a camshaft increases horsepower in a car. The answer is, unfortunately, it doesn’t really work that way.
In fact, replacing your camshaft with a higher-performance one can actually have negative consequences for your engine. Here’s why.
Regular Camshaft vs. Performance Camshaft
We are giving you an example for a better understanding. When you are running the engine with 10 or 20 RPM (imaginary), it will take the piston 2 seconds or so to complete one cycle.
As the speed is slow, we will require the cam loves shaped. Here, the piston will start moving downward. It will go through the intake stroke and as a result, the intake valves will open.
When the piston will bottom out, the intake valve will close. On the other end, when the piston will bottom out at the end of the combustion stroke, the exhaust valve will open.
Also, it will close when the piston will be done with the exhaust stroke. When the speed will be as slow as we mentioned, the process will run smoothly. But the problem arises when the RPM increases.
Imagine that you have chosen 4000 RPM for running the engine. For covering the RPM, the valves will need to open and close 2000 times per minute. As the speed is high, the piston has to move faster than before too.
And eventually, the air-fuel mixture that will rush inside the cylinder will move quicker too! Keep in mind that when the air/fuel will burn, the work of the piston is to push the exhaust gases out of the cylinder.
When the intake valve will open and the piston will start the intake stroke, the air/fuel mixture will accelerate inside the cylinder.
When the piston will reach the bottom stroke, the air/fuel movement will be higher. If you slam the intake valve shut, the air/fuel mixture will stop and will not enter the cylinder.
If the intake valve is opened for a little more time, the air/fuel movement in the combustion chamber will force it inside the cylinder when the piston will start the compression stroke. Here, you have to check out the compression ratio.
In short, with the engine’s speed, the air/fuel will move faster. And for this, we will need the intake valve to stay open for a longer period. When the speed is high, we will require the valve to open wider. This parameter is known as valve lift.
The cam lobe profiles take care of the valve lift. Unlike the stock cam, the performance camshaft helps in increasing the duration and timing of the opening of the valve when the engine starts.
As a result, the horsepower increases, and the acceleration get faster. When you get a new cam, adjust the timing and tweak it!
Changing the Camshafts
Yes, camshafts are prodigious in the increment of horsepower but you cannot rush into the job and add change them out of nowhere.
Before you try to swap camshafts, go through them and make sure that changing the camshaft will increase the stock engine performance and do well for your vehicle. Don’t run and swap different cams.
Also, never think that the bigger cams are the better. In this case, you must keep your eyes on the rpm. Cams that have smaller duration numbers will increase the horsepower at low rpm. If you are into daily driving or towing, such cams can be beneficial.
On the other hand, when you escalate the duration, you will see that the peak power your engine can make is increased.
In such scenarios, you move the power curve high rpm range. When you design a cam’s profile with more lift, the duration increases in the high-lift regions where the cylinder heads can flow more air.
The high valve lift short-duration cams can give you incredible responsiveness along with added power and torque. However, we do not recommend high-lift cams as they are not highly dependable.
For the engine builders, we suggest you get rocker arms if you want to add some power to the cam’s performance by multiplying the movement of the tappet lift.
How much horsepower does a camshaft add?
If you are settling for a normal bolt on your vehicle, a camshaft will provide you with 390-450. However, this completely depends on the cam you pick up along with the bolt-ons. If you are dealing with a head/cam vehicle, you can get 425-475 added horsepower. This might be more or less depending on so many necessary factors.
Does a bigger cam add horsepower?
In general, yes, a bigger cam than stock will afford you more horsepower. But it will do it to a certain degree.
On the other hand, if you pick up a cam that is way bigger for the flow numbers of stock heads, it will require the engine to operate in an irregular RPM range.
This will not result in any HP gain. So, the bigger the better is not the key always.
What does a cam do for performance?
No matter whether you are settling for a camshaft in a pushrod engine or the overhead cam engine, the opening and closing of the valves are always in the hand of the camshafts. As a result, the air fuel that goes inside and outside the engine is also controlled by the camshaft. Eventually, it plays an important role in the engine’s performance.
How much HP does a Stage 3 cam add?
The Stage 3 cam is designed in a manner that works with the larger valves and port work. These cams are incredible for the EFI system and the upgraded carburetor. With the cam, the power band will start moving higher in the RPM range.
The RPM rate will be more or less 2500 to 6000. For a street application, this can be the biggest cam for your vehicle. In the races and the got street applications, you can use this cam too!
Now you have learned if a camshaft increases horsepower or not and how it does the job you expect! No matter how much increment a camshaft can provide, it is necessary to check and double-check the benefits that the addition of new camshafts can provide you!
A professional can help you more with the idea of swapping camshafts. You should get your hands on performance camshafts if you want horsepower and torque improvement.
Don’t forget to comment below on what increment your engine has got with the addition of some new camshafts!
I’m Md Nurul Islam, a blogger, and automotive enthusiast also. I started creating this website because I have always loved cars and bikes.