S&S Cycle 106″ Big Bore Kit For Harley Big Twin 2007-2017

S&S 106″ Big Bore: Unlocking the Heart of the Twin Cam for 2026

The S&S Cycle 106″ Big Bore Kit for 2007-2017 Harley-Davidson Twin Cam models represents the 2026 pinnacle of bolt-on engine architecture. For owners of 96ci and 103ci platforms, reaching the next level of performance often felt out of reach without a complete engine teardown and expensive crankcase machining. S&S has engineered a solution that allows riders to reach 106ci displacement using high-precision 3.927″ bore cylinders that fit directly into the stock case spigots. This kit transforms the power character of your motorcycle, providing a significant increase in mid-range torque and top-end horsepower. For the rider seeking secure, industrial-strength utility and a displacement that revitalizes the late-model Twin Cam platform, the S&S 106″ kit is the definitive 2026 upgrade.

Forged Precision and Thermal Stability

What sets the S&S 106″ kit apart in the 2026 marketplace is the uncompromising quality of its internal components. The kit features forged aluminum pistons with a 10.0:1 compression ratio, which provides a significant boost in throttle response while remaining compatible with 2026 pump fuels. These pistons are engineered with advanced skirt coatings to reduce friction and mechanical noise, ensuring your engine remains quiet at idle but ferocious under load. The cylinders themselves are constructed with high-tensile cast-in liners that resist warping under the extreme cylinder pressures of a high-output 2026 build. This thermal resilience is critical for maintaining a perfect ring seal, preventing oil consumption, and ensuring the high-output 2026 presence and longevity that professional engine builders demand.

Expert Installation & Performance Advice

As specialists in Twin Cam engine dynamics, we recommend the 106″ kit as the foundation for any 2026 performance project. Pro Tip: To truly unlock the potential of 106 cubic inches, pair this kit with an S&S 585 Cam and the S&S Stealth Air Cleaner to ensure the engine breathes efficiently. Installation Note: Always check your piston-to-valve clearance if using high-lift aftermarket cams with this kit. Maintenance Note: Proper 2026 break-in is essential; follow a strict heat-cycle regimen and change the oil after the first 50, 500, and 1,000 miles to ensure the rings seat perfectly. Safety Note: Because this kit increases airflow and compression, a fuel management upgrade (like a Dynojet Power Vision) is mandatory to prevent lean conditions and ensure your 2026 engine remains powerful.

The Professional Standard for Twin Cam Displacement Upgrades

Choosing the S&S Cycle 106″ Big Bore Kit means investing in unmatched mechanical stability and a refined power signature. It offers a unique combination of modern metallurgical strength and a proven design that honors the performance legacy of the Harley-Davidson brand. For the rider who wants a high-output 2026 presence and a flawless engineering finish, the S&S 106″ Kit is the unmatched leader. Supersize your power, eliminate the lag, and ride the distance.

Features

• At 3.927″ bore, these cylinders have the largest bore that S&S feels can safely be used in a cylinder with stock spigot diameter
• This kit is only offered with S&S cylinders because the cylinder liner material in S&S cylinders is much stronger, and has proven its ability to stand up to the added power in numerous dyno pulls, street miles, and a lot of quarter mile drag strip runs
• There is a trade-off for the ease of installation, which is that only one piston oversize is available for this kit
• No need to bore or even split the cases, just do the cylinder swap
• In addition to the ease of installation they look great because the cylinders match the stock finish of your engine
• 10:1 Compression ratio with stock heads, 9.7:1 with S&S 89cc heads