What Does a Harley Camshaft Upgrade Actually Do for Your Motorcycle?

When Harley-Davidson riders start shopping for performance Harley Davidson parts, a camshaft upgrade is usually near the top of the list. But what does changing your Harley camshaft actually do? Is it simply about adding peak horsepower, or can the right cam change how your motorcycle performs throughout the entire RPM range?

The answer comes down to choosing the right cam—and pairing it with the right supporting modifications.

Mickey Cohen recently demonstrated this with a Gen1 Milwaukee-Eight 114 that arrived at his shop essentially stock. After installing his recommended combination of performance parts, the motorcycle went from approximately 92 horsepower and 101 lb-ft of torque to 119.2 horsepower and 125 lb-ft of torque.

That's a significant transformation without building an entirely new motor.

Here's what riders should understand before choosing their next Harley Davidson camshaft.

What Does a Harley Camshaft Do?

Your camshaft controls the opening and closing of the engine's valves. Changing the cam profile affects when those valves open, how far they open, and how long they remain open.

Those changes influence how efficiently the engine can move air through the cylinders, which directly impacts its power characteristics.

But as you may know, Mickey doesn't believe that "bigger is automatically better". For Mickey it's all about ride-ability. 

Different cams are designed to produce power in different portions of the RPM range. An aggressive cam that's poorly matched to your engine or riding style may sacrifice low-end performance to create power higher in the RPM range.

For a street Harley, that's not always desirable.

The goal should be to select a Harley camshaft that creates usable horsepower and torque where you actually ride.

A Real-World M8 114 Camshaft Upgrade

During a recent Mickey Cohen Motorsports build, Mickey started with a stock Gen1 Milwaukee-Eight 114 and installed his MC8-23XE camshaft along with supporting modifications.

The combination included:

• MC8-23XE camshaft
• 64mm throttle body
• 64mm ported intake
• 6.2 high-flow injectors
• 2-into-1 exhaust setup
• Performance air cleaner
• DynoJet Power Vision tuner and professional dyno tuning

The results speak for themselves.

Mickey explained:

“Went from 92 horsepower and 101 pounds of torque to 119.2 and 125 torque.”

That's roughly a 27-horsepower (29%) increase from a relatively straightforward combination of performance Harley Davidson parts.

More importantly, the setup was designed around creating a powerful but highly rideable street motorcycle.

Why the Right Cam Matters

One of Mickey's biggest points is that riders shouldn't select a cam based solely on how aggressive it sounds or how much peak horsepower it could theoretically produce.

Power delivery matters.

As Mickey explains:

“When you do a right cam with a small throttle body, they are more twitchy. They're snappier, but they don't make as good of numbers and they don't have as much drivability to them.”

A cam that's too aggressive for the combination can create a motorcycle that feels lazy at lower RPM before suddenly coming alive higher in the rev range.

That may look exciting on a dyno chart, but it doesn't necessarily make for the best street bike.

Mickey describes himself as a “drivability guy,” and that's an important philosophy when selecting Harley Davidson camshaft kits.

The objective isn't simply to create the biggest peak number. It's to build an engine that produces strong, predictable power throughout the range you actually use.

The MC8-23XE for Gen1 Milwaukee-Eight Motors

For riders with a Gen1 Milwaukee-Eight, Mickey specifically recommends the MC8-23XE for several stock-displacement applications.

According to Mickey:

“It's a 23XE. It works great in a stock Gen1 114 or 117.”

He describes the MC8-23XE as an advancement of the earlier 22XE. However, he also makes an important distinction for riders who already own the previous cam:

“If you have a 22XE, you don't need this... It's not that big of an improvement for what it costs you to do.”

For riders starting with a stock Gen1 M8, however, the MC8-23XE provides a compelling foundation for a performance package.

Mickey also notes that this particular cam isn't his preferred solution for Gen2 engines, reinforcing why choosing a Harley Davidson camshaft based on your specific generation and engine combination is important.

Why Upgrade the Throttle Body?

A camshaft can change how much air the engine is capable of moving, but the rest of the intake system needs to support that airflow.

That's why Mickey pairs the MC8-23XE with a 64mm throttle body on his recommended build.

The larger throttle body allows additional airflow into the engine while also changing how the motorcycle delivers power.

According to Mickey:

“When you put the 64mm body on it, it makes it more linear. A linear bike is easier to ride.”

That linearity is a big part of creating a performance motorcycle that's enjoyable on the street.

You don't just want the motorcycle to make more power. You want that power to arrive smoothly and predictably when you roll into the throttle.

Don't Forget About Fuel

More airflow requires adequate fuel delivery.

Mickey recommends 6.2 injectors when combining the 64mm throttle body with the MC8-23XE.

He explains:

“The 64 millimeter body allows more air to come in, and then in order to supplement that, you have to do bigger injectors.”

Riders who retain their factory throttle body can still run the MC8-23XE, but Mickey recommends moving to 5.5 injectors rather than retaining the factory injectors.

Why?

Because the original injectors may not provide sufficient injector duty cycle for the new combination.

This is exactly why quality Harley Davidson camshaft kits often include—or recommend—supporting components rather than treating the camshaft as an isolated modification.

Intake and Exhaust Matter Too

Getting air into the engine is only half the equation. You also need an effective way to move exhaust gases out.

For this particular combination, Mickey recommends a quality air cleaner and 2-into-1 exhaust setup.

He also saw measurable improvements from the ported Screamin' Eagle intake used on the test bike.

Mickey says:

“I can tell you the ported intake makes four more horsepower compared to the non-ported intake.”

Four horsepower might not sound enormous by itself, but performance builds are often about creating a combination in which every component complements the others.

Camshaft, throttle body, intake, injectors, air cleaner, exhaust, and tuning all contribute to the final result.

Why Dyno Tuning Completes the Package

Installing the best performance Harley Davidson parts won't automatically optimize your motorcycle.

Once airflow, fueling, and valve timing have changed, the motorcycle needs to be properly calibrated.

Mickey's advice after installing the complete combination is straightforward:

“You just bolt [it] in and you just need a decent dyno tuner.”

A professional dyno tune allows the tuner to calibrate fueling, ignition, and other parameters around the exact parts installed on your motorcycle.

That's particularly important because no two performance builds are necessarily identical.

Is a Harley Camshaft Upgrade Worth It?

For riders looking for a meaningful increase in performance without replacing the entire engine, a camshaft can offer an excellent balance of power, cost, and street usability.

Mickey's Gen1 M8 114 provides a great example.

The motorcycle started around 92 horsepower and 101 lb-ft of torque. With the MC8-23XE and its supporting upgrades, Mickey recorded 119.2 horsepower and 125 lb-ft of torque.

But the numbers only tell part of the story.

The right Harley camshaft can also change where the engine produces its power and how smoothly that power is delivered. Pairing it with the appropriate throttle body, injectors, intake, exhaust, and tune can create a motorcycle that's noticeably stronger without sacrificing everyday rideability.

That's ultimately what riders should look for when comparing Harley Davidson camshaft kits.

Don't choose a cam based solely on the biggest advertised horsepower number. Build a complete combination around your engine, motorcycle, and riding style.

When all those pieces work together, a Harley Davidson camshaft upgrade can completely change the way your motorcycle feels every time you twist the throttle.

Ready to upgrade your Gen1 M8 Harley with a Harley Davidson Performance kit designed by Mickey Cohen himself?

Click the link below to shop now:

https://mickeycohenmotorsports.com/pages/m8-harley-davidson-performance-kits