If you're looking to boost your Shovelhead's performance in 2024, you'll want to evaluate the best big bore kits available. Each option, from the S&S Cycle 910-0481 to the V-Twin Evolution kits, offers unique benefits that can enhance your ride's power and efficiency. Choosing the right kit isn't just about performance; it's also about compatibility and durability. So, what factors should you weigh when making your decision? Let's explore the top contenders and see which one might just be the perfect fit for your motorcycle.

Key Takeaways

• The S&S Cycle 910-0481 kit offers superior cooling efficiency and a perfect customer rating of 5.0 stars, making it a top choice for performance.
• V-Twin 11-1258 is a bolt-on kit with a 10:1 compression ratio, ensuring enhanced performance for mid-1980s to late 1990s models.
• The S&S Cycle 107' Wrinkle Black kit features the largest bore size at 3.937 inches, requiring no machining for installation.
• V-Twin 11-0082 provides a complete assembly for 1966-1984 Big Twin models, boasting a strong customer rating of 5.0 stars.

S&S Cycle 910-0481 98 Big Bore Kit Black

The S&S Cycle 910-0481 98 Big Bore Kit Black is an ideal choice for motorcycle enthusiasts seeking enhanced cooling efficiency and superior machining quality in their Shovelhead engines.

This kit features thicker fins that greatly improve cooling, ensuring optimal performance during long rides. Customers have given it a perfect 5.0 out of 5 stars, praising its exceptional machining quality.

The kit includes all necessary gaskets for installation, though it excludes top rocker box, breather, and carburetor gaskets. Since its debut on February 4, 2015, it has garnered attention in the Powersports Cylinder Heads category, ranking #718.

With its robust construction and reliable performance, the S&S Cycle 910-0481 remains a top choice for those looking to upgrade their motorcycle's engine.

Best For: Motorcycle enthusiasts looking to enhance their Shovelhead engines with improved cooling efficiency and high-quality machining.

Pros:

• Exceptional machining quality ensures reliable performance and durability.
• Thicker fins provide better cooling, making it ideal for long rides.

Cons:

• Excludes top rocker box, breather, and carburetor gaskets, which may require additional purchases.
• Best Sellers Rank indicates limited visibility compared to more popular products.

https://www.amazon.com/dp/B00T6J5HLI?tag=theseasonedwr-20

V-Twin 11-1258 – 83 Evolution Big Bore Cylinder Kit

Designed for riders seeking enhanced performance, the V-Twin 11-1258 – 83 Evolution Big Bore Cylinder Kit offers a powerful 10:1 compression forged piston setup without the need for case boring.

This bolt-on silver cylinder kit includes two high-quality cylinders and Wiseco forged pistons, making installation straightforward for compatible models like FXST, FXR, FLST, FLT, and FXD from the mid-1980s to late 1990s.

Weighing in at 20 pounds and measuring 18 x 10 x 10 inches, it's designed to provide exceptional reliability and longevity, often lasting hundreds of thousands of miles.

With a perfect customer rating of 5.0 stars, this kit stands out for its quality and performance, making it a top choice for enthusiasts looking to upgrade their bikes.

Best For: Riders of FXST, FXR, FLST, FLT, and FXD models from the mid-1980s to late 1990s seeking enhanced engine performance and reliability.

Pros:

• High-quality components including Wiseco forged pistons that ensure durability.
• Easy installation with no case boring required, making it accessible for DIY enthusiasts.

Cons:

• Top end gasket sold separately, which may increase overall installation costs.
• Limited compatibility with other models outside the specified range.

https://www.amazon.com/dp/B00UMDXX2W?tag=theseasonedwr-20

S&,S Cycle 107&Prime, Wrinkle Black Big Bore Kit 910-0500

With its bolt-on installation and no need for machining, the S&S Cycle 107' Wrinkle Black Big Bore Kit 910-0500 is perfect for Shovelhead enthusiasts looking to enhance performance without complicated modifications.

This kit features a bore size of 3.937 inches, making it the largest bore available for stock engines. Weighing 19.5 pounds, it measures 16.5 x 13.5 x 11 inches and includes durable CP pistons, top and bottom cylinder gaskets, and a robust cylinder liner with a tensile strength of 40,000 psi.

Customers have given it a stellar rating of 5.0 out of 5 stars. With no additional machining required, this kit is a hassle-free upgrade for riders wanting to boost their bike's performance.

Best For: Shovelhead enthusiasts seeking a straightforward and effective performance upgrade without the need for extensive modifications.

Pros:

• Bolt-on installation allows for easy upgrade without machining.
• High tensile strength cylinder liner ensures durability and longevity.

Cons:

• Limited compatibility may not suit all motorcycle models.
• Weight of 19.5 pounds could be considered heavy for some riders.

https://www.amazon.com/dp/B01LW7KK0T?tag=theseasonedwr-20

V-Twin 11-1253 – 83 Evolution Big Bore Cylinder Kit

V-Twin's 11-1253 – 83 Evolution Big Bore Cylinder Kit is ideal for riders looking to boost their 83 cubic inch engine's performance without the hassle of case boring.

This bolt-on black cylinder kit features a 10:1 compression Wiseco forged piston kit, honed for final fitment, ensuring compatibility and reliability.

It includes both front and rear domed pistons, crafted from aluminum cylinders with a cast-in steel sleeve for durability.

Designed for various models, including FXST, FXR, FLST, FLT, and FXD, the kit meets the needs of many riders.

While customer ratings sit at 4.2 out of 5 stars, some users report fitment issues and concerns with seller support, so prompt return initiation is advised.

Best For: Riders looking to enhance their 83 cubic inch engine's performance with a reliable and easy-to-install big bore kit.

Pros:

• Quick shipping and good packaging reported by customers.
• High-quality components, including Wiseco forged pistons.

Cons:

• Some users experience fitment issues with the product.
• Limited seller support for return queries.

https://www.amazon.com/dp/B00UMDXW50?tag=theseasonedwr-20

V-Twin 11-0082 – Replica Shovelhead Cylinder Head Set

Offering a complete assembly with unleaded valve intake seats, the V-Twin 11-0082 – Replica Shovelhead Cylinder Head Set is an excellent choice for enthusiasts looking to upgrade their 1966-1984 Big Twin models.

This set features rubber band type heads that come fully assembled, including cast iron valve guides, nitrated valves, and a stock-type valve spring kit.

Designed for peak performance, it accommodates long reach spark plugs and flat seals for the intake manifold.

Weighing 19.6 pounds and measuring 16 x 11 x 6 inches, it fits all FL and FX Shovelheads seamlessly.

With a stellar customer rating of 5.0 out of 5 stars, this head set ranks highly among automotive parts, making it a must-have for serious motorcycle enthusiasts.

Best For: Motorcycle enthusiasts looking to upgrade their 1966-1984 Big Twin models with high-quality cylinder heads.

Pros:

• Fully assembled with all necessary components for easy installation.
• High customer satisfaction with a perfect 5.0 out of 5-star rating.

Cons:

• Weighty at 19.6 pounds, which may require additional support during installation.
• Limited compatibility, as it only fits specific models (1966-1984 Big Twins).

https://www.amazon.com/dp/B00UMDZ2C6?tag=theseasonedwr-20

V-Factor 60151 Big Bore Replacement Cylinders For Shovelhead

The V-Factor 60151 Big Bore Replacement Cylinders are ideal for Shovelhead enthusiasts seeking to enhance engine performance with a bore size of 3.625 inches.

Made from durable cast iron, these cylinders are painted black to match stock components seamlessly.

Riders can choose between standard length or .200 inches taller options for stroked engines, catering to specific performance needs.

Weighing in at 12.35 lbs and measuring 18 x 18 x 16 inches, these components are designed for easy installation.

Sold individually, they come with a 30-day return policy through Amazon and warranty information available upon request.

V-Factor remains committed to providing competitive pricing, responding to customer feedback to guarantee value for those looking to upgrade their Shovelhead engines.

Best For: Shovelhead motorcycle enthusiasts looking to enhance their engine's performance with high-quality replacement cylinders.

Pros:

• Durable cast iron construction ensures longevity and reliable performance.
• Available in two lengths to accommodate various engine configurations, supporting both standard and stroked engines.

Cons:

• Sold individually, which may require purchasing multiple units for a complete upgrade.
• Weight of 12.35 lbs could add to the overall weight of the motorcycle, potentially affecting handling.

https://www.amazon.com/dp/B07F28JKBQ?tag=theseasonedwr-20

V-Twin 11-0533 – 88 Evolution Big Bore Cylinder Black

Designed to enhance stock Evolution engines, the V-Twin 11-0533 – 88 Evolution Big Bore Cylinder Black is an ideal choice for riders looking to boost performance in their FXR, FXD, FLST, FLT, and FXST models from 1984 to 1998.

Weighing in at 8.2 pounds and measuring 9 x 9 x 9 inches, this cylinder features a bore size of 92.075mm and a compression ratio of 9.25:1 with flat top pistons and rings.

Riders must note that case boring is necessary for final fitment. It's crucial to order the top end gasket kit separately to complete the installation.

This big bore cylinder stands out in the market, offering a reliable upgrade for enthusiasts seeking enhanced engine performance.

Best For: Riders looking to enhance the performance of their stock Evolution engines in specific Harley-Davidson models from 1984 to 1998.

Pros:

• Improves engine performance with a larger bore size and optimized compression ratio.
• Compatible with multiple models, making it a versatile choice for various Harley-Davidson riders.

Cons:

• Requires case boring for proper fitment, which may necessitate additional labor or costs.
• Top end gasket kit must be purchased separately, adding to the overall expense.

https://www.amazon.com/dp/B00UMDY9RA?tag=theseasonedwr-20

Factors to Consider When Choosing a Shovelhead Big Bore Kit

When you're choosing a Shovelhead big bore kit, several key factors come into play.

You'll want to contemplate engine compatibility, compression ratios, and the materials used for durability.

Additionally, think about the installation complexity and the performance enhancements each kit offers.

Engine Compatibility Requirements

Choosing the right big bore kit for your Shovelhead means confirming compatibility with your specific model and existing engine components. Start by verifying that the kit is designed for Shovelhead models manufactured between 1966 and 1984. This confirms a proper fit and ideal performance.

Next, check the compatibility with your engine's current components, such as pistons and gaskets. Some kits might require additional parts for installation, so it's crucial to have a complete understanding of what you'll need. Additionally, confirm that the bore size of the kit aligns with your engine's specifications. Mismatched bore sizes can negatively impact performance and fitment.

If you're looking for a straightforward installation process, consider kits that don't require case boring. These bolt-on kits can save you time and hassle.

Compression Ratio Considerations

Understanding the compression ratio is vital for optimizing your Shovelhead's performance and ensuring it meets your riding needs.

The compression ratio greatly impacts engine performance; generally, higher ratios provide more power, but they also require higher-octane fuel to prevent knocking. A common choice for big bore kits is around 10:1, striking a balance between performance and fuel requirements, making it suitable for most street applications.

If you're prioritizing reliability over maximum performance, think about a lower compression ratio like 9:1. This option allows for the use of regular fuel, which can enhance the longevity of your engine. However, the specific engine design and camshaft type can also influence what compression ratio works best for you. Performance cams typically benefit from higher ratios, so keep that in mind when making your choice.

It's essential to evaluate the entire engine setup, including carburetion and ignition timing, when selecting a compression ratio. Ensuring compatibility across these components will help you maximize performance and achieve the riding experience you desire.

Material and Durability

Material quality and durability are essential factors that can greatly influence the performance and longevity of your Shovelhead big bore kit. When choosing a kit, consider the materials used; aluminum is often favored for its lightweight and superior heat dissipation compared to cast iron. This can lead to better engine cooling and overall performance.

Tensile strength is another critical aspect—look for cylinder liners with ratings around 40,000 psi. Higher tensile strength means greater resistance to deformation and wear, enhancing durability over time. Additionally, the finish of the cylinders matters; anodized finishes tend to resist corrosion better than painted ones, helping maintain both aesthetics and functionality.

Don't overlook the pistons included in the kit. Forged pistons are generally stronger and more durable than their cast counterparts, providing improved performance under stress.

Installation Complexity

Installation complexity can vary markedly between Shovelhead big bore kits, so it's vital to assess the ease of installation before making your selection.

Look for kits that offer bolt-on installation, as these typically require no machining or case boring, making the process simpler. Some kits come with all the necessary components, while others might leave you searching for additional gaskets or parts, adding to the complexity.

Consider the weight of the components, too. Lighter kits are generally easier to handle during installation, reducing the chances of mishaps.

Compatibility with your specific Shovelhead model is important, as some kits are designed to fit various models, while others have more restrictive requirements that could complicate your project.

Performance Enhancements Offered

What kind of performance enhancements can you expect from a Shovelhead big bore kit? First off, these kits increase your engine's displacement, which can greatly boost both horsepower and torque. You'll notice a substantial improvement in performance, making your rides more exhilarating. Many kits feature high-compression pistons with ratios like 10:1 or 9.25:1, optimizing combustion efficiency and maximizing power output.

Additionally, enhanced cooling features, such as thicker fins, help dissipate heat more effectively. This not only improves your engine's performance stability but also extends its longevity, ensuring you get more miles out of your investment.

Installation is often a breeze with bolt-on options, allowing you to upgrade without the need for extensive machining, making these performance enhancements accessible to every rider.

Plus, when you choose kits made from high-quality materials—like forged pistons and durable cylinder liners—you're ensuring reliability even under increased power conditions.

Price and Value Comparison

When considering a Shovelhead big bore kit, evaluating the price and value can greatly impact your decision-making process.

Start by comparing kits like the S&S Cycle 910-0481 and V-Twin 11-1253, which have customer ratings of 5.0 and 4.2 stars, respectively. These ratings indicate high satisfaction relative to their price points.

Cost-effectiveness is vital, especially with the V-Twin 11-1258 kit, which includes a Wiseco forged piston kit and doesn't require case boring, potentially saving you on additional machining costs.

Don't overlook warranty and return policies, as many kits offer a 30-Day Return Guarantee, providing peace of mind for your investment.

Customer feedback regarding machining quality and performance longevity is another important factor. Some users report high-quality components yielding several hundred thousand miles of use, enhancing perceived value.

Lastly, consider the size and material of the cylinders, as aluminum cylinders typically cost more than cast iron options. This material choice greatly impacts pricing, making it essential to assess what aligns best with both your budget and performance goals.

Frequently Asked Questions

What Is the Average Horsepower Gain From Big Bore Kits?

When you install a big bore kit, you can typically expect an average horsepower gain of 10 to 20%. This boost varies depending on your engine's base setup and tuning.

By increasing the cylinder size, you're allowing more air and fuel into the combustion chamber, which enhances power output.

Just remember, proper tuning and supporting modifications are essential to fully realize these gains and guarantee your engine runs smoothly.

Are Big Bore Kits Street Legal in All States?

When it comes to revamping your ride with a big bore kit, you're stepping into a world of possibilities.

However, you should know that street legality varies by state. While some places embrace the extra power, others might have stricter emissions and noise regulations that could rain on your parade.

It's crucial to check your local laws before diving into the upgrade, so you can enjoy the thrill without any legal hiccups.

How Long Does Installation Typically Take?

Installation of big bore kits typically takes anywhere from a few hours to a full day, depending on your experience and the specific setup.

If you've got some mechanical skills, you might complete it faster. However, if you're unfamiliar with the process, it's wise to allocate extra time or consider getting help from a professional.

Always make sure to follow the manufacturer's instructions for a successful installation and peak performance.

What Is the Warranty Duration for These Kits?

When you're considering big bore kits, the warranty duration can vary depending on the manufacturer.

Typically, you'll find warranties lasting from one to two years, but some brands may offer extended options.

It's essential to read the fine print, as certain conditions might apply.

Always ask the seller about what's covered, so you're fully informed.

Having a solid warranty gives you peace of mind as you upgrade your bike for enhanced performance.

Do Big Bore Kits Affect Fuel Efficiency?

Big bore kits can affect your bike's fuel efficiency, but the impact varies.

You might notice a decrease in mileage if you're pushing for more power, as larger cylinders often consume more fuel.

However, if you adjust your riding style or tune your engine properly, you could maintain or even improve efficiency.

Ultimately, it's about finding the right balance between performance and fuel consumption to suit your riding needs.

Conclusion

Upgrading your Shovelhead with a big bore kit can truly transform your ride, boosting both horsepower and torque.

Did you know that some big bore kits can increase your engine's displacement by up to 20%, delivering a noticeable performance improvement?

With options like the S&S Cycle and V-Twin kits, you're sure to find a perfect match for your bike.

So, gear up and get ready to experience a whole new level of power on the open road!