JEGS Tech Specialist

Pete Mitchell

When upgrading or replacing a camshaft, one of the most critical decisions you’ll make is choosing between a flat tappet vs roller tappet camshaft. Both options have their strengths and weaknesses, and the right choice depends on your vehicle’s intended use, engine setup, and performance goals. In this guide, we’ll break down the differences between roller cam vs flat tappet camshafts, their pros and cons, and help you decide which one is best for your build.

Flat Tappet

Flat tappet camshafts have been a staple in internal combustion engines for decades, especially in older cars and classic builds. They feature lifters (or tappets) with a flat contact surface that follows the camshaft lobes.

How Flat Tappets Work

• The lifter rides directly on the camshaft lobe, with a flat or slightly convex surface.
• The cam lobe's motion transfers to the lifter, which then actuates the pushrod and valve.

Advantages of Flat Tappet Camshafts

1. Cost-Effective: Flat tappet camshafts are generally less expensive than roller tappets, making them a popular choice for budget builds.
2. Simplicity: The design is straightforward and easier to install in older engines without needing additional modifications.
3. Availability: Widely available for classic engines, especially those manufactured before the 1990s.

Disadvantages of Flat Tappet Camshafts

1. Increased Wear: Flat tappets experience more friction due to direct contact with the camshaft lobes, leading to faster wear over time.
2. Oil Requirements: They require specific oils with zinc additives (ZDDP) for proper lubrication and to prevent excessive wear.
3. Power Limitations: At high RPMs, the increased friction can reduce performance and longevity compared to roller cams.

Flat tappets are an excellent option for restorations or builds where authenticity and cost control are primary considerations. However, they may not be the best choice for high-performance applications.

Roller Tappet

Roller tappet camshafts use lifters equipped with a small roller wheel at the contact point, allowing them to glide over the camshaft lobes with minimal friction. This design offers significant advantages in both performance and durability.

How Roller Tappets Work

• The lifter's roller wheel follows the camshaft lobe, reducing friction and wear.
• Roller cams typically feature more aggressive lobe profiles, which allow for improved valve timing and airflow.

Advantages of Roller Tappet Camshafts

1. Reduced Friction: The roller design significantly reduces friction, leading to less wear and tear on both the lifter and camshaft.
2. Higher Performance Potential: Roller cams can accommodate more aggressive lobe designs, allowing for higher lift and longer duration, which improves power output.
3. Longevity: Roller tappets last longer than flat tappets, making them ideal for high-mileage or high-performance builds.
4. Modern Compatibility: Many modern engines come with roller cams from the factory, simplifying installation or upgrades.

Disadvantages of Roller Tappet Camshafts

1. Higher Cost: Roller cams and lifters are more expensive than their flat tappet counterparts.
2. Complexity: Installation may require additional or different components, such as a camshaft retainer plate or different length pushrods, in engines originally designed for flat tappets.
3. Weight: Roller lifters are slightly heavier, which can increase valve train mass, though this is negligible for most builds.

Roller tappets are the go-to choice for high-performance engines, modern vehicles, or any build where durability and power are top priorities.

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Flat Tappet vs Roller: Key Differences

Choosing the Right One for You

When deciding between a roller tappet vs flat tappet, you’ll need to consider several factors, including your budget, performance goals, and intended use for your vehicle.

Choose a Flat Tappet Camshaft If:

• You’re building or restoring a classic car and want to keep it period-correct.
• Your project is budget-conscious, and you’re not aiming for extreme performance.
• Your engine operates at moderate RPMs with no need for aggressive lobe profiles.

Choose a Roller Tappet Camshaft If:

• You’re looking for maximum performance and durability.
• Your build involves high RPMs or high horsepower applications.
• You want modern technology with reduced maintenance concerns.

Shop for Camshafts at JEGS

Understanding the differences between flat tappet vs roller camshafts is essential for choosing the right setup for your engine. While flat tappets offer affordability and simplicity, roller tappets deliver better performance, longevity, and efficiency. Whether you’re restoring a classic or pushing the limits of your build, the right camshaft will unlock your engine’s full potential.

JEGS offers a wide selection of camshafts, lifters, and components to complete your build. If you need help selecting the right camshaft or have questions about your project, our JEGS Tech Support Team is available at 1-800-345-4545 to provide expert advice and guidance.