Eagle 104564250 4.25″ Cast Steel Crankshaft for Big Block Chevy

Description

Product Overview

The Eagle 104564250 crankshaft is a premium cast steel component designed specifically for Big Block Chevrolet applications. With a 4.25 inch stroke, this crankshaft provides the exact geometry required for high‑displacement engines, delivering the torque and horsepower potential that performance builders demand. The crankshaft is forged from high‑grade cast steel, a material known for its excellent tensile strength, fatigue resistance, and ability to withstand the extreme pressures generated during aggressive combustion cycles. Each unit is machined to tight tolerances, ensuring a perfect fit with the engine block, main bearings, and connecting rods.

Key specifications include a manufacturer part number of 104564250, an OEM part number that matches the original equipment, and a bobweight of 2420, which contributes to a balanced rotating assembly and reduces vibration at high RPMs. The external balance feature means the crankshaft is pre‑balanced at the factory, eliminating the need for aftermarket balancing services and providing a smoother power delivery curve. The one‑piece rear seal design further enhances reliability by preventing oil leakage and maintaining proper lubrication throughout the engine’s operating range.

Dimensions of the crankshaft measure 28 x 8.3 x 9 inches, allowing it to fit within the standard engine bay of most Big Block Chevrolet platforms without modification. The product has earned a solid reputation among enthusiasts, reflected in its high customer rating and its ranking as #17 in the Automotive Performance Engine Crankshafts category on major retail platforms. Whether you are rebuilding a classic muscle car, upgrading a street‑legal hot rod, or assembling a dedicated race engine, the Eagle 104564250 crankshaft offers the durability, precision, and performance needed to achieve your goals.

Usage

This crankshaft is ideally suited for a variety of high‑performance scenarios. In street‑driven muscle cars, the 4.25″ stroke provides a noticeable increase in low‑to‑midrange torque, improving acceleration and overall drivability. For drag racing applications, the balanced rotating assembly and robust construction allow the engine to sustain high RPMs and rapid acceleration without compromising reliability. The crankshaft also performs well in endurance racing environments where consistent power output and long‑term durability are critical.

Installation is straightforward for experienced mechanics familiar with Big Block Chevrolet engine assemblies. The crankshaft aligns with the standard main bearing caps and oil pump locations, reducing the need for custom machining or additional adapters. After installation, the engine benefits from the reduced harmonic vibrations due to the external balance, which translates into smoother operation, lower wear on ancillary components, and a longer service life for the entire powertrain.

Because the crankshaft is made from cast steel, it tolerates the high temperatures and pressures typical of forced‑induction setups, such as supercharging or turbocharging, making it a versatile choice for both naturally aspirated and boosted configurations. The one‑piece rear seal ensures that oil remains within the crankcase, protecting the bearings and reducing the risk of oil starvation during high‑G cornering or sudden throttle changes.

Why Choose Us

Choosing the Eagle 104564250 crankshaft means selecting a component that combines engineering excellence with proven performance. Eagle Specialty Products has a long history of supplying high‑quality engine parts to the performance community, and this crankshaft reflects that legacy through its meticulous manufacturing process and rigorous quality control standards. Each crankshaft undergoes a multi‑stage inspection, including dimensional verification, material certification, and dynamic balancing checks, ensuring that every unit meets or exceeds OEM specifications.

Our commitment to customer satisfaction extends beyond the product itself. We provide comprehensive technical support, detailed installation guides, and a responsive after‑sales service team ready to assist with any questions or concerns. In the unlikely event of a defect, we offer a straightforward warranty process that emphasizes quick resolution and minimal downtime for your project.

Furthermore, the Eagle crankshaft is backed by a network of authorized distributors and service centers, guaranteeing that you have access to genuine parts and professional expertise wherever you are located. This level of support, combined with the crankshaft’s superior material properties and precise engineering, makes it a reliable choice for both seasoned professionals and dedicated hobbyists seeking to maximize engine performance.

Key Features

• High‑grade cast steel construction delivers exceptional strength and fatigue resistance for demanding applications.
• Precise 4.25″ stroke and 2420 bobweight provide optimal torque characteristics and smooth power delivery.
• Factory‑balanced external balance eliminates the need for aftermarket balancing, reducing installation time and cost.
• One‑piece rear seal design prevents oil leakage, ensuring consistent lubrication and engine reliability.
• Comprehensive technical support and warranty service give you confidence and peace of mind throughout the build.

FAQ

What engines are compatible with this crankshaft?

The Eagle 104564250 crankshaft is designed for Big Block Chevrolet engines, including classic 427, 454, and similar displacement models that require a 4.25″ stroke. It fits standard engine blocks without the need for custom machining.

Do I need to have the crankshaft balanced after purchase?

No additional balancing is required. The crankshaft comes pre‑balanced from the factory, providing a ready‑to‑install component that meets performance specifications out of the box.

Is the rear seal replaceable if it wears out?

Yes, the rear seal is a one‑piece design that can be replaced if necessary. Replacement seals are available through Eagle Specialty Products and authorized distributors.

Can this crankshaft be used in forced‑induction applications?

Absolutely. The cast steel material and robust construction are well‑suited for supercharged or turbocharged setups, handling the increased pressures and temperatures associated with forced induction.

What warranty does Eagle provide for this crankshaft?

Eagle offers a limited warranty that covers manufacturing defects for a specified period. Details can be obtained from the seller or directly from Eagle Specialty Products, and the warranty process is designed to be quick and hassle‑free.