Buy S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026 – AmericanV-twin.com https://www.american-twin.com Upgrade Your Ride Without Overpaying Sat, 07 Feb 2026 08:32:28 +0000 en-US hourly 1 https://wordpress.org/?v=7.1.3 https://www.american-twin.com/wp-content/uploads/2025/11/cropped-gg-1-32x32.png Buy S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026 – AmericanV-twin.com https://www.american-twin.com 32 32 S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026 https://www.american-twin.com/product/ss-cycle-124-big-bore-kit-for-harley-107-milwaukee-eight-2017-2026-2/ Sat, 07 Feb 2026 08:30:45 +0000 https://www.american-twin.com/?post_type=product&p=14388 S&S Cycle 124" Big Bore Kit is a high-performance displacement upgrade for 2017-2026 Harley-Davidson 107ci Milwaukee-Eight engines.
  • No Case Machining: Massive 4.250" bore cylinders designed to bolt directly onto factory 107" crankcases for a secure 2026 installation.
  • Forged Aluminum Pistons: Features 11.0:1 compression ratios, precision-engineered to handle high-output 2026 performance loads.
  • Improved Cooling: Cylinders feature a high-strength liner and optimized fin geometry for superior 2026 thermal management.
  • Complete Performance Package: Includes cylinders, forged pistons, rings, wrist pins, clips, and premium head/base gaskets.

[The Definitive M8 Power Upgrade, Delivering Unmatched 2026 Displacement Gains and Industrial-Strength Reliability]

]]> S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026

S&S 124″ Big Bore: Unlocking the Heart of the M8 for 2026

The S&S Cycle 124″ Big Bore Kit for 2017-2026 Harley-Davidson 107ci Milwaukee-Eight models represents the 2026 pinnacle of bolt-on engine architecture. In the M8 era, displacement is the most direct path to massive torque, but traditionally, reaching these figures required a complete engine teardown and expensive crankcase machining. S&S has engineered a solution that allows 107ci owners to reach 124ci displacement using high-precision 4.250″ bore cylinders that fit directly into the stock case spigots. This kit transforms the power character of your motorcycle, providing an immediate and violent increase in acceleration and passing power. For the rider seeking secure, industrial-strength utility and a displacement that commands respect, the S&S 124″ kit is the definitive 2026 upgrade for the 107″ platform.

Forged Precision and Thermal Stability

What sets the S&S 124″ kit apart in the 2026 marketplace is the uncompromising quality of its internal components. The kit features forged aluminum pistons with an 11.0:1 compression ratio, which provides a significant boost in “snap” and 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 whisper-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.

S&S 124″ M8 Big Bore Kit Technical Specifications

  • Fitment: 2017-2026 Harley-Davidson Milwaukee-Eight 107″ (Touring and Softail).
  • Bore Size: 4.250″ Bore (Increases 107ci to 124ci).
  • Compression Ratio: 11.0:1 with stock 107″ cylinder heads.
  • Pistons: Forged aluminum with specialized anti-friction coatings.
  • Installation: Bolt-on design; no crankcase machining required.
  • Gaskets: Includes MLS (Multi-Layer Steel) head gaskets for a 2026 leak-proof seal.
  • Origin: 100% Designed, Cast, and Machined in the USA by S&S Cycle.

Expert Installation & Performance Advice

As specialists in Milwaukee-Eight engine dynamics, we recommend the 124″ kit as the foundation for any serious 2026 project. Pro Tip: To truly unlock the potential of 124 cubic inches, pair this kit with an S&S 550 Cam and the S&S 55mm Aluminum Manifold to ensure the engine isn’t “choked” at high RPM. 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 vastly increases airflow and compression, a professional dyno tune via Dynojet Power Vision is mandatory to prevent detonation and ensure your 2026 engine runs cool and powerful.

The Professional Standard for M8 Displacement Upgrades

Choosing the S&S Cycle 124″ 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 124″ Kit is the unmatched leader. Supersize your power, eliminate the lag, and ride the distance.

Features

  • 107″ to 124″ bolt on bore kit (no machining required)
  • 4.250″ Bore
  • Forged pistons
  • 11.1:1 Compression ratio
  • Includes gaskets and hardware

 

Product Style AmericanV-twin Item # Catalog Number Store Sku MFR. Product # Availability
Non-Highlighted Fins 55187 55187 910-0681A In Stock: Ships next business day
Highlighted Fins 55188 55188 910-0625A In Stock: Ships next business day


This Product Fits

Harley Davidson
Electra Glide Standard FLHT 2019, 2020, 2021, 2022
Electra Glide Ultra Classic FLHTCU/I 2017, 2018, 2019
Electra Glide Ultra Limited FLHTK 2017-2024
Electra Glide Ultra Limited Low FLHTKL 2017, 2018, 2019
Road Glide 3 FLTRT 2026
Road Glide CVO ST FLTRXSTSE 2024, 2025, 2026
Road Glide FLTRX 2017-2026
Road Glide Limited FLTRK 2020, 2021, 2022, 2023, 2024
Road Glide Limited FLTRXL 2026
Road Glide Special FLTRXS 2017-2023
Road Glide ST FLTRXST 2022, 2023
Road Glide Ultra FLTRU 2017, 2018, 2019
Road King FLHR/I 2017-2022
Road King Special FLHRXS 2017-2025
Softail Breakout FXBR 2018, 2019
Softail Deluxe FLDE 2018, 2019, 2020
Softail Fat Bob FXFB 2018, 2019
Softail Fat Boy FLFB 2018, 2019
Softail Heritage Classic 114 FLHCS 2020, 2021, 2022, 2023, 2024
Softail Heritage Classic FLHC 2018-2026
Softail Low Rider FXLR 2018, 2019, 2020
Softail Slim FLSL 2018, 2019, 2020, 2021
Softail Sport Glide FLSB 2018, 2019, 2020, 2021
Softail Standard FXST 2020, 2021, 2022, 2023, 2024
Softail Street Bob 114 FXBBS 2021, 2022, 2023, 2024
Softail Street Bob FXBB 2018, 2019, 2020, 2025, 2026
Street Glide CVO ST FLHXSTSE 2026
Street Glide FLHX/I 2017-2026
Street Glide Special FLHXS 2017-2023
Street Glide ST FLHXST 2022, 2023

]]> S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026 https://www.american-twin.com/product/ss-cycle-124-big-bore-kit-for-harley-107-milwaukee-eight-2017-2026/ Sat, 07 Feb 2026 08:25:35 +0000 https://www.american-twin.com/?post_type=product&p=14381 S&S Cycle 124" Big Bore Kit is a high-performance displacement upgrade for 2017-2026 Harley-Davidson 107ci Milwaukee-Eight engines.
  • No Case Machining: Massive 4.250" bore cylinders designed to bolt directly onto factory 107" crankcases for a secure 2026 installation.
  • Forged Aluminum Pistons: Features 11.0:1 compression ratios, precision-engineered to handle high-output 2026 performance loads.
  • Improved Cooling: Cylinders feature a high-strength liner and optimized fin geometry for superior 2026 thermal management.
  • Complete Performance Package: Includes cylinders, forged pistons, rings, wrist pins, clips, and premium head/base gaskets.

[The Definitive M8 Power Upgrade, Delivering Unmatched 2026 Displacement Gains and Industrial-Strength Reliability]

]]> S&S Cycle 124″ Big Bore Kit For Harley 107″ Milwaukee-Eight 2017-2026

S&S 124″ Big Bore: Unlocking the Heart of the M8 for 2026

The S&S Cycle 124″ Big Bore Kit for 2017-2026 Harley-Davidson 107ci Milwaukee-Eight models represents the 2026 pinnacle of bolt-on engine architecture. In the M8 era, displacement is the most direct path to massive torque, but traditionally, reaching these figures required a complete engine teardown and expensive crankcase machining. S&S has engineered a solution that allows 107ci owners to reach 124ci displacement using high-precision 4.250″ bore cylinders that fit directly into the stock case spigots. This kit transforms the power character of your motorcycle, providing an immediate and violent increase in acceleration and passing power. For the rider seeking secure, industrial-strength utility and a displacement that commands respect, the S&S 124″ kit is the definitive 2026 upgrade for the 107″ platform.

Forged Precision and Thermal Stability

What sets the S&S 124″ kit apart in the 2026 marketplace is the uncompromising quality of its internal components. The kit features forged aluminum pistons with an 11.0:1 compression ratio, which provides a significant boost in “snap” and 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 whisper-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.

S&S 124″ M8 Big Bore Kit Technical Specifications

  • Fitment: 2017-2026 Harley-Davidson Milwaukee-Eight 107″ (Touring and Softail).
  • Bore Size: 4.250″ Bore (Increases 107ci to 124ci).
  • Compression Ratio: 11.0:1 with stock 107″ cylinder heads.
  • Pistons: Forged aluminum with specialized anti-friction coatings.
  • Installation: Bolt-on design; no crankcase machining required.
  • Gaskets: Includes MLS (Multi-Layer Steel) head gaskets for a 2026 leak-proof seal.
  • Origin: 100% Designed, Cast, and Machined in the USA by S&S Cycle.

Expert Installation & Performance Advice

As specialists in Milwaukee-Eight engine dynamics, we recommend the 124″ kit as the foundation for any serious 2026 project. Pro Tip: To truly unlock the potential of 124 cubic inches, pair this kit with an S&S 550 Cam and the S&S 55mm Aluminum Manifold to ensure the engine isn’t “choked” at high RPM. 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 vastly increases airflow and compression, a professional dyno tune via Dynojet Power Vision is mandatory to prevent detonation and ensure your 2026 engine runs cool and powerful.

The Professional Standard for M8 Displacement Upgrades

Choosing the S&S Cycle 124″ 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 124″ Kit is the unmatched leader. Supersize your power, eliminate the lag, and ride the distance.

Features

  • 107″ to 124″ bolt on bore kit (no machining required)
  • 4.250″ Bore
  • Forged pistons
  • 11.1:1 Compression ratio
  • Includes gaskets and hardware

 

Product Style AmericanV-twin Item # Catalog Number Store Sku MFR. Product # Availability
Non-Highlighted Fins 55187 55187 910-0681A In Stock: Ships next business day
Highlighted Fins 55188 55188 910-0625A In Stock: Ships next business day


This Product Fits

Harley Davidson
Electra Glide Standard FLHT 2019, 2020, 2021, 2022
Electra Glide Ultra Classic FLHTCU/I 2017, 2018, 2019
Electra Glide Ultra Limited FLHTK 2017-2024
Electra Glide Ultra Limited Low FLHTKL 2017, 2018, 2019
Road Glide 3 FLTRT 2026
Road Glide CVO ST FLTRXSTSE 2024, 2025, 2026
Road Glide FLTRX 2017-2026
Road Glide Limited FLTRK 2020, 2021, 2022, 2023, 2024
Road Glide Limited FLTRXL 2026
Road Glide Special FLTRXS 2017-2023
Road Glide ST FLTRXST 2022, 2023
Road Glide Ultra FLTRU 2017, 2018, 2019
Road King FLHR/I 2017-2022
Road King Special FLHRXS 2017-2025
Softail Breakout FXBR 2018, 2019
Softail Deluxe FLDE 2018, 2019, 2020
Softail Fat Bob FXFB 2018, 2019
Softail Fat Boy FLFB 2018, 2019
Softail Heritage Classic 114 FLHCS 2020, 2021, 2022, 2023, 2024
Softail Heritage Classic FLHC 2018-2026
Softail Low Rider FXLR 2018, 2019, 2020
Softail Slim FLSL 2018, 2019, 2020, 2021
Softail Sport Glide FLSB 2018, 2019, 2020, 2021
Softail Standard FXST 2020, 2021, 2022, 2023, 2024
Softail Street Bob 114 FXBBS 2021, 2022, 2023, 2024
Softail Street Bob FXBB 2018, 2019, 2020, 2025, 2026
Street Glide CVO ST FLHXSTSE 2026
Street Glide FLHX/I 2017-2026
Street Glide Special FLHXS 2017-2023
Street Glide ST FLHXST 2022, 2023

]]>