Introducing the MHP 131 Torque Eater and MHP 131 Ass Eater – Moonshine Horsepower’s 131 Cubic Inch M8 Engine Builds, our most popular setups, engineered for precision power and seamless fit with no engine case modifications required. We start with Harley-Davidson’s battle-tested 4.310″ cylinders – the toughest in the game – and hone them in-house to a perfect 4.313″ on our Moonshine Horsepower Hone of Power. This ensures dead-straight, round bores with a dialed-in finish for our Total Seal Rings. Paired with MHP Pistons featuring Lateral Gas Ports for unbeatable ring seal, DLC-coated Piston Pins, a Darkhorse-built 4.500″ Flywheel, and MHP Lightning Rods from CP Carrillo, these builds are pure muscle. Our MHP Street Fighter Heads with +1.5mm oversized valves and MHP CNC-Ported 66mm Intake Manifold unleash ferocious flow. The MHP 131 Ass Eater is tuned for solo riders chasing top-end horsepower with solid low-end torque – fearless past 6,000 RPMs. The MHP 131 Torque Eater, built for two-up riding, delivers monstrous low-RPM torque with plenty of punch up top. Our top-selling setups let you dominate your way, no case mods needed.

Check out our dyno sheets below to pick your perfect camshaft and exhaust combo.