Overview

The S&S Sidewinder® 4" Big Bore Kit transforms your 96" or 103" Twin Cam engine into a torque-packed 110" powerhouse — without ever splitting the cases. Designed as a true bolt-on upgrade, it delivers reliable horsepower gains while retaining stock engine height and factory serial numbers.

Available in Silver or Black finishes to match your engine’s aesthetic.

Key Specifications

• Displacement: 110 cubic inches
• Bore Size: 4.000"
• Stroke Length: 4.375" (4-3/8")
• Compression Ratio: Approx. 10.5 : 1 (with stock 85 cc heads)
• Base Finish: Powder-coated — available in Silver or Black
• Engine Compatibility: 2007–2017 Twin Cam 96" & 103"
• Installation: Bolt-on – no crankcase machining or case splitting required
• Engine Height: Retains stock height

Included Components

• Matched 4.000" big-bore cylinders with forged pistons
• Piston pins, rings and circlips
• Head and base gaskets
• All required installation hardware

Features

• Bolt-In Installation: Engine can remain in the frame during installation.
• Massive Power Gains: Boosts displacement to 110" for stronger low-end torque and smoother power delivery.
• Durable Construction: Cast aluminum cylinders with ductile iron liners for superior strength and heat transfer.
• Stock Compatibility: Works with OEM heads and compression ratios for a street-friendly ride.
• No Case Machining: Fully bolt-on design retains factory serial numbers.

Finish Options

• Silver: Classic aluminum finish for OEM look.
• Black with Machines Fins: Stealth appearance for modern dark-themed builds.

Performance Summary

The Sidewinder® 4" Big Bore Kit delivers significant torque and horsepower increases across the rev range — ideal for riders who want real performance gains without complex engine work. It’s a proven, reliable upgrade that keeps your engine looking factory-clean but performing like a true power build.