S&S CYCLE T143 Long-Block Engine 310-0833A

The S&S Cycle T143 is purpose-built for riders who demand maximum performance without sacrificing chassis compatibility. At double the horsepower of a stock motor, this ultra-performance long-block delivers the displacement and power necessary to dominate the track—while fitting into your existing frame with zero modifications. This is a race-proven powerplant designed for experienced builders and riders who understand that extreme performance demands precision tuning, technical expertise, and acceptance of the trade-offs inherent to maximum output.

Built entirely in the USA, the T143 features CNC-machined S&S B3 cylinder heads, a high-flow oil pump, and S&S 635 gear drive cams paired with 1.725:1 rocker arms for .674" of total valve lift. The three-piece flywheels, super stock T2 crankcases with reed breather valve, and premium high-performance tappets ensure durability under extreme load. Note that this engine requires a separate carburettor/intake system, ignition components, T143-specific or custom exhaust, and an oil line installation kit—making it essential to plan your build with a qualified technician.

• 143 cubic inches displacement
• 10.47:1 compression ratio
• CNC-machined B3 cylinder heads
• Two-bolt exhaust flanges
• Super stock T2 crankcases
• Reed breather valve
• Three-piece flywheels
• S&S high-flow oil pump
• S&S 635 gear drive cams
• 1.725:1 rocker arms
• .674" total valve lift
• Premium high-performance tappets
• Wrinkle black finish
• Fits stock chassis—no modifications
• Made in USA
• One-year warranty
• Not compatible with HD Softail