For anyone stepping into the world of LS and LT engine performance, the camshaft is one of the most critical and misunderstood components to get right. Whether you’re hunting for horsepower, chasing that loping idle, or looking for a cam profile that balances drivability with power, understanding camshaft fundamentals is key. To help break things down, we connected with Luke Bandt, Sales Manager at Howards Cams, to dig into what matters when choosing a camshaft for your LS, LT, or even small-block Chevy build.

Lift: More Isn’t Always Better

Cam lift is often the first number that draws attention, especially among street and strip enthusiasts. Lift refers to how far the valve opens off its seat, and in theory, more lift should mean more airflow and more power. But in practice, it’s not that simple.

“Most people get very wrapped up in lift.” Bandt told us. “They try to get a cam where their cylinder heads make peak flow. Truth be told, engines are incredibly forgiving to lift numbers and most times don’t need as much lift as you would think.”

That may sound surprising, especially when data on cylinder head flow shows optimal flow at higher valve lifts. But real-world performance proves otherwise. “We have .450-inch lift SBC circle track motors that make over 500 wheel horsepower through a two-barrel carb,” he continued.

Too much lift without the air demand from the cylinder can cause the port velocity to nose over or revert. Both of these issues can reduce horsepower. — Luke Bandt, Howards Cams Sales Manager

In the LS and LT world, where aggressive cam specs are common, it’s easy to fall into the trap of assuming higher lift equals higher performance. However, unless the cylinder head can continue to flow efficiently at that lift, additional valve lift can actually introduce problems rather than solve them.

So, what determines whether you go higher or lower on the lift?

“It all comes down to where we want an engine to make peak power,” Bandt explained. “When that RPM is determined, we calculate what CFM the motor needs to ingest at a given duration. Then we turn to the cylinder head flow data and match them accordingly.”

In max-effort engines, the lift can be viewed as a percentage of the valve size to ensure the valve doesn’t shroud the port. But for most street builds, high lift isn’t a requirement. In fact, it can be a liability.

All cam lobes convert rotational motion into linear lift. It starts at the base circle (A), ramps up the opening flank (B), peaks at the lobe nose (C), and drops down the closing flank (D) before returning to the base (A).

“Too much lift without the air demand from the cylinder can cause port velocity to nose over or revert. Both of these issues can reduce horsepower,” Bandt warned. The phenomenon is particularly common with small-block Chevy builds, where people often bolt on 1.6:1 rocker arms hoping for an easy power bump, only to unknowingly hurt performance by upsetting the airflow characteristics of the cylinder head.

Duration: Choppy Idles And Power Curves

If lift tells you how far the valve opens, duration tells you how long it stays open. It’s measured in crankshaft degrees and is closely tied to valve timing and the engine’s RPM range.

It might seem counterintuitive, but camshaft duration is measured in degrees of crankshaft rotation. Keep in mind, the crankshaft completes two full turns for every single rotation of the camshaft. Photo Credits: Speedway Motors

Many enthusiasts associate duration with the choppy, loping idle sound that defines aggressive cams. But that’s not entirely accurate. “Overlap. That’s all,” Bandt said. “The time at which your exhaust valve is closing and the intake starts to open. That’s what gives you the lope.”

Still, duration plays a vital role in shaping the power curve.

“Duration is a direct representation of what your valve events actually are. When we spec a camshaft, we are really setting those events,” Bandt explained. “Generally, we look at our intake close point and our exhaust open point as a starting point to develop the power curve the customer is looking for.”

Adding duration tends to push the powerband higher into the RPM range. That’s great for race cars that live at high RPM, but not always ideal for street builds that need low-end torque.

“If you love the sound, you might think, ‘why not just put all the duration in it?’” Bandt said. “Eventually, you’ll run into one of two problems. First, if an engine has a lower static compression ratio, a significant amount of duration will bleed off, resulting in so much cylinder pressure at idle that the cam appears to smooth out. Second, you’ll hit RPM limitations. Valve events need to be in certain positions to make efficient power.”

A common mistake is trying to use duration to mask a mild build or to chase sound without matching the rest of the engine combo. As Bandt explained, “If the events are too close together, the engine flat out won’t perform like we need it to.”

Lobe Separation Angle (LSA): The Balance Between Sound And Function

The third major factor in camshaft design is lobe separation angle, or LSA. The result is the angle (in camshaft degrees) between the peak lift of the intake and exhaust lobes. This factor significantly influences idle quality, vacuum levels, and the perceived width or peakiness of the powerband.

This timing graph shows valve lift versus crankshaft degrees. The red curve represents exhaust valve events; the blue curve shows intake events. Key specs like lobe center angle (LCA), intake and exhaust centerlines (ICA/ECA), and valve overlap are highlighted; they are critical for tuning power, drivability, and idle quality.

“A tighter LSA will increase overlap, therefore increasing the chop,” Bandt said. “The trade-off is, as overlap increases, engine vacuum decreases.”

That has serious implications for anyone using power brakes, mild EFI setups, or even daily-driving their LS build. While a tighter LSA might sound aggressive and hit harder, it could come at the cost of drivability and tuning.

“Moving the LSA around also changes the shape of the power curve. Wider generally will make a flatter power curve, and in some applications, it makes more average power. A tighter LSA makes a snappy, peaky power curve. Bandt explained that while you can generally achieve a higher peak power number, the performance may be lower in other areas of the power curve.

Boosted Applications: LSA Matters Even More

Camshaft selection gets more complicated when forced induction enters the mix. Whether it’s a supercharged LT4 or a turbocharged 5.3L LS, cam events must be tuned for boosted airflow dynamics.

“In most cases, you’ll end up with a smaller camshaft in a boosted application,” Bandt said. “We are now dealing with the density of the charge air instead of it just being at atmospheric pressure.”

The key concern becomes controlling reversion and backflow. “The more we can separate the exhaust valve close point from when the intake starts to open (wider LSA), the less boost will escape through the closing exhaust valve,” he said.

As for blower vs. turbo cam differences, Bandt noted that “blower and turbo can look very similar depending on the application.” What matters most is managing airflow, minimizing boost bleed, and matching the cam’s valve events to the specific behavior of the forced induction system.

LS And LT-Specific Camshaft Considerations

Modern LS and LT platforms are more forgiving than older small-block Chevys thanks to better cylinder heads, improved valvetrain stability, and high-flow intake and exhaust systems. That gives cam designers more room to get aggressive, but it also means there’s more potential to do it wrong.

This chart from Speedway Motors compares flat tappet and roller camshafts, both hydraulic and solid. Roller solid cams offer the highest RPM and power potential, but require more maintenance and cost. Hydraulic roller cams strike a balance of power and street reliability, while flat tappet cams remain budget-friendly options with lower spring load and RPM limits.

“A lot of people underestimate how well the stock LS heads flow, even at lower lift numbers,” Bandt noted. That’s why choosing a cam based solely on lift can backfire. Instead, matching the cam to your intended use, RPM range, and airflow characteristics remains the priority.

In Gen V LT engines like the LT1 and LT4, the conversation changes slightly due to direct injection and variable valve timing (VVT). While VVT is often deleted in performance builds, it can be retained and even tuned with the right cam profile. Howards Cams offers dedicated camshafts for both VVT and non-VVT LT engines, optimized for naturally aspirated or boosted setups.

Howards Cams: A Trusted Name In Performance

Founded in the 1940s, Howards Cams has built a legacy of performance rooted in racing and innovation. Today, they offer camshafts, valvetrain components, and complete kits for everything from vintage small-blocks to cutting-edge Gen V LT engines, and more. With a focus on in-house grinding, dyno development, and application-specific tuning, Howards has remained a go-to source for serious builders and first-timers alike. Whether you’re looking to hit a specific horsepower number, chase a dragstrip time, or just bring a mild LS to life, their tech team is available to help dial in your combo.