S&S 128ci Big Bore Cylinder & Piston Kit - Harley M8
Harley-Davidson Milwaukee-Eight 114ci & 117ci Engines (2017-2024)
The ultimate displacement upgrade for Milwaukee-Eight 114 and 117 owners, delivering tire-shredding horsepower without removing the engine from the frame.
Includes currency-adjusted exchange rate, South African customs clearance, and insured door-to-door courier dispatch from Cape Town.
Engineering & Performance Characteristics
Cylinder spigots are precision machined to slide directly into factory crankcase bores with zero case machining required.
Engineered Highlights & Performance Gains
- Increases displacement from 114ci to a massive 128 cubic inches without case boring
- Yields dyno power outputs exceeding 135 horsepower and 145 lb-ft of torque
- Includes premium forged pistons, tool steel wrist pins, and rings
- Maintains factory engine height and cosmetic appearance seamlessly
Technical Specifications
- Brand & Origin
- S&S Cycle
- Product SKU / MPN
- SS-910-0685 / 910-0685
- System Architecture
- Bolt-On Big-Bore Engine Conversion
- Material Construction
- Cast Iron Liners with Ductile Iron Cylinders & Forged Pistons
- Surface Finish
- Wrinkle Black Powder Coated Cylinders with Highlighted Fins
- Sound Profile
- Thunderous Big-Bore V-Twin Combustion Roar
- ECU Tuning Status
- Tuning Required / Highly Advised
- Tuning Guidance
- Requires complete ECU calibration, high-flow injectors, and exhaust.
- Manufacturer Warranty
- 2-Year Limited Manufacturer Warranty
- Availability & Dispatch
- Express Sourcing (Specialized order, 7-10 business days delivery)
Included in Box
- Pair of 128ci Cylinders
- Forged Piston Set
- Wrist Pins & Circlips
- Head & Base Gaskets
Verified Fitment List
Confirmed compatible models for S&S 128ci Big Bore Cylinder & Piston Kit - M8 114 to 128ci. Roxstar verifies model, year, and frame clearances prior to dispatch.
Not sure if your specific model year, engine size, or aftermarket luggage brackets are compatible? Our Cape Town technicians confirm all dimensions before taking payment.
Submit your bike specs for verification →South African Courier Logistics
All orders are dispatched from our Cape Town hub via fully trackable courier services. We deliver directly to private residences, commercial addresses, or designated motorcycle performance workshops.
About S&S Cycle
Explore the full range of performance exhaust systems, tuning accessories, and precision engineered components from S&S Cycle.
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S&S 128ci Big Bore Cylinder & Piston Kit - M8 114 to 128ci FAQs
Clear, evidence-backed answers regarding motorcycle exhaust fitment and supply.
How do I request fitment verification and pricing for S&S 128ci Big Bore Cylinder & Piston Kit - M8 114 to 128ci?
Does this S&S Cycle system require ECU re-tuning?
What is the delivery timeline for delivery within South Africa?
What warranty coverage applies to SS-910-0685?
Technical & Category Guides
- S&S Cycle Brand ShowcaseExplore all performance products and engineering heritage from S&S Cycle.
- Performance Products CatalogBrowse all 220+ performance exhausts, headers, and tuning upgrades.
- Fitment Confirmation GuideLearn how we verify motorcycle year, model, and sensor bung specs.
- Exhaust Tuning & Fuel MappingECU tuning, fuel management, and air-fuel ratio advisory.
Enquire on S&S 128ci Big Bore Cylinder & Piston Kit - M8 114 to 128ci
Provide your motorcycle make, model, year, and displacement for direct fitment confirmation and an official written quote.