S&S Cycle 640C Chain Drive Camshaft Kit - Harley Dyna & Big Twin
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.
Unleash serious mid-range performance in your high-displacement Harley-Davidson Dyna or Big Twin with the S&S Cycle 640C Chain Drive Camshaft Kit. This kit is specifically designed for engines of 95 cubic inches or larger, especially those running higher compression ratios. It's a complete solution to significantly boost your V-twin's power output in the crucial mid-range RPMs.
Why riders pick this
- Optimized for 95+ cubic-inch engines
- Boosts mid-range power significantly
- Includes cam bearings and gaskets
- Designed for 10.5:1 to 11.5:1 compression
The S&S Cycle 640C camshaft kit is engineered for riders pushing the limits of their big twin engines. When paired with a 95+ cubic-inch displacement and a 10.5:1 to 11.5:1 compression ratio, this chain-drive cam delivers a powerful surge through the mid-range, making it ideal for aggressive riding and maximizing your engine's potential. The kit includes all necessary components for a comprehensive upgrade.
Aggressive Performance, Complete Kit
- Designed for 95+ cubic-inch engines and higher compression
- Significantly increases mid-range performance
- Includes cam bearings and gearcover gaskets for installation
- Chain-drive design for proven reliability
Built for Power Demands
This S&S Cycle camshaft kit provides everything you need for a robust performance upgrade. It's tailored for those who have already invested in larger displacement and higher compression, ensuring that every component works in harmony to produce maximum power. Get ready to experience a whole new level of mid-range pull on your Harley.
Specifications
- Brand: S&S Cycle
- Manufacturer Part #: 106-4399
- Category: Engine Components / Camshafts
- Weight: 3.9 lb
Common questions
What's included in the kit?
The kit includes camshafts, cam bearings, gearcover gaskets, and complete installation instructions.
Will this work on my 88-cubic-inch engine?
No, this cam kit is designed for engines of 95 cubic inches or larger displacement.
Do I need to adjust my compression ratio before installing?
The cam is engineered for engines running 10.5:1 to 11.5:1 compression. Achieving this compression ratio is crucial for optimal performance with this camshaft. Always confirm fitment with your specific year and model using our Shop by Bike tool before ordering.
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.
| BRAND | S&S Cycle |
| TYPE | Camshafts |
| SKU | T14-663339 |
| WEIGHT | 3.9 lb |
