S&S CYCLE T143 Long Block Engine - Black 310-0837A

The S&S T143 Long Block delivers double the horsepower of a stock Harley engine while maintaining fitment in your existing chassis—no frame modifications required. Built for serious racers and performance enthusiasts willing to master the additional complexity and maintenance demands of an ultra-high-output motor. This is peak displacement performance for stock-chassis applications, engineered to dominate the track.

Every component in the T143 is engineered for maximum output: CNC-machined B3 heads, gear-drive cams for reliable valve timing, and premium high-performance tappets work together to deliver consistent power delivery. The 3-piece flywheels reduce rotating mass, while the 1.725:1 rocker arms and .674" total lift optimize valve event dynamics. S&S TC3 oil management ensures lubrication under extreme operating conditions.

Important: This is a race-focused engine with compromised longevity, increased noise, and heightened vibration compared to stock applications. Installation and tuning require professional expertise. Not compatible with HD Softail models. Engine noise and damage from abuse are not covered under warranty.

• 143 cubic inches
• 10.47:1 compression ratio
• S&S B3 CNC-machined heads
• 2-bolt exhaust flanges
• S&S 635 gear-drive cams
• S&S TC3 oil pump
• 1.725:1 rocker arms
• .674" total valve lift
• Premium high-performance tappets
• 3-piece flywheels
• Gloss black finish
• Stock chassis compatible
• No frame modifications
• Made in USA
• 1-year warranty
• MPN: 310-0837A