S&S Cycle KN93 Alt/Gen Knucklehead Engine Fits Harley-Davidson Big Twin 1970-1999
Build a 1970-Up custom Big Twin around a knucklehead silhouette without committing to a vintage-only chassis. The S&S KN93 Alt/Gen carries authentic knucklehead styling on alt/gen-style crankcases that bolt to the modern 1970-Up primary-case pattern, with a complete S&S long-block assembled and preset out of the crate.
Key Features
- Complete assembled 93 cubic-inch knucklehead-style crate engine with alt/gen-style crankcases (1948-1999-style front motor mount geometry, 1970-Up primary-case bolt pattern)
- 1958-1965-style splined sprocket-shaft flywheel assembly with Timken sprocket-shaft bearing
- Black powder-coated cylinders and heads over a natural-finish crankcase
- S&S Super E carburetor preset from the factory
- S&S Stealth air cleaner
- S&S Super Stock single-fire ignition system with polished billet timer, preset from the factory
- S&S valve train with solid lifters and a cast generator-style cam cover
- Oil-filter mount for generator location and a sprocket-shaft length suited to 1970-Up primary and transmission
- One-year S&S warranty
Technical Specifications
- Displacement: 93 cubic inches
- Bore x Stroke: 3-5/8 inch x 4-1/2 inch
- Compression Ratio: 8.2:1
- Rated Output: 61.6 hp / 83.7 lb-ft torque
- Crankcases: Alt/gen-style with 1948-1999-style front motor mount, 1970-Up primary-case bolt pattern
- Flywheel Assembly: 1958-1965-style splined sprocket-shaft with Timken bearing
- Cam Cover: S&S cast generator-style
- Valve Train: S&S with solid lifters
- Carburetor: S&S Super E (preset)
- Air Cleaner: S&S Stealth
- Ignition: S&S Super Stock single-fire with polished billet timer (preset)
- Finish: Natural crankcase with black powder-coated cylinders and heads
- Warranty: 1 year
- Country of Origin: United States (Viola, Wisconsin)
Fitment Notes
- Compatible with Harley-Davidson 1970-Up Big Twin custom chassis using the 1970-Up primary-case bolt pattern.
- The alt/gen-style sprocket shaft suits either alternator or generator-style primary configuration.
- This is a custom-builder engine, not a stock-OEM direct-replacement; not intended for 1936-1969 generator-only chassis (covered by the separate S&S P93 / KN93 Generator products).
- Chassis-side primary, transmission interface, exhaust, and ignition wiring harness are supplied by the installer.
- Refer to the Fitment tab for the full chassis breakdown.
- Not affiliated with or endorsed by Harley-Davidson.
