Eagle Chevrolet LS 4340 3.900in Stroke 24 Tooth Reluctor Forged Crankshaft

Forged from 4340 steel, this Eagle crankshaft is built for serious performance in Chevrolet LS engines. It features a 3.900-inch stroke, which is a common choice for increasing displacement and torque in LS builds. The crankshaft includes a 24-tooth reluctor wheel, essential for proper engine management system operation on many LS applications.

Eagle starts with a non-twist forging process for this crankshaft, ensuring maximum strength and rigidity. The fillet radii at the journal transitions are a robust .125 inches, which adds significant strength to the crankshaft. Because of these larger fillet radii, you'll need to use chamfered or narrowed bearings when installing this crank. The surface is then nitrided and micropolished. Nitriding hardens the surface for improved wear resistance, while the micropolishing creates an exceptionally smooth finish on the bearing journals, which is critical for reducing friction and ensuring long bearing life.

This crankshaft is designed for demanding applications where reliability and strength are paramount. It’s a solid foundation for a high-performance engine build. Ensure you have the correct chamfered bearings and appropriate assembly lube on hand before beginning installation.