About S&S Cycle
S&S Cycle has built American V-twin performance parts in Viola, Wisconsin since 1958 — flywheels, carburetors, cams, cylinder heads and complete crate engines. When a Harley owner talks about a 124, a 128 or a 131 build, they are usually talking about S&S. Few names carry more weight with engine builders in this space.
Build the foundation for serious power with S&S Cycle 4.425" Bore Crankcases for 2006-2017 Harley-Davidson Dyna models. Machined from robust 356-T6 aircraft-grade aluminum, these crankcases feature thicker wall sections for superior strength and durability. They are designed as a direct replacement or as the ideal starting point for high-performance custom engine builds.
Why riders pick this
- 4.425" bore crankcases for 2006-2017 Dyna
- 356-T6 aircraft-grade aluminum construction
- Thicker wall sections for increased strength
- Includes Timken® sprocket shaft bearing
- Pre-installed studs and cam bearings
- Reinforced front motor mount
The S&S Cycle 4.425" Bore Crankcases are engineered to handle the demands of high-performance Harley-Davidson Dyna engines. Constructed from premium 356-T6 aircraft-grade aluminum, they boast thicker wall sections compared to stock, providing enhanced rigidity and longevity. This crankcase comes prepared with a Timken® sprocket shaft bearing, pre-installed studs, and cam bearings, streamlining your engine assembly process.
Robust Foundation for Power
- Constructed from 356-T6 aircraft-grade aluminum for superior strength
- Thicker wall sections enhance durability under stress
- Features a reliable Timken® sprocket shaft bearing
- Pre-installed studs and cam bearings simplify assembly
- Reinforced front motor mount for improved stability
- Tough powder coat finish for lasting protection
Ready for Your Custom Build
Whether you're replacing a damaged stock crankcase or embarking on a custom big-inch engine project, these S&S Cycle crankcases are built to perform. They provide ample clearance for aggressive strokes and high-lift cams, making them suitable for a wide range of performance configurations. Each crankcase includes a Manufacturer's Statement of Origin (MSO), making it ready for registration as the heart of your new engine.
Specifications
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Brand: S&S Cycle
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Manufacturer Part #: 310-0859
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Bore: 4.425 inch
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Category: Engine Components / Crankshafts
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Weight: 36.5 lb
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Material: 356-T6 aircraft-grade aluminum
Common questions
Do these S&S crankcases fit 2006-2017 Dyna models?
Yes, these S&S Cycle 4.425" bore crankcases are a direct fit for all 2006-2017 Harley-Davidson Dyna models, serving as a stock bore replacement.
What material are these crankcases made from?
These S&S crankcases are machined from high-quality 356-T6 aircraft-grade aluminum, known for its strength and durability in demanding engine applications.
Are these suitable for custom high-performance engine builds?
Absolutely, these crankcases are designed with thicker wall sections and clearances for larger strokes and high-lift cams, making them an excellent foundation for custom performance engine builds.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
