Eagle Engine Crankshaft Rotating Assembly

Eagle Specialty Products: Engine Crankshaft Rotating Assemblies

When it comes to building a high-performance engine from the bottom up, few decisions are more important than choosing the right rotating assembly. Eagle Specialty Products has spent decades earning its reputation as one of the most trusted names in this space, and their engine crankshaft rotating assembly kits are a prime example of why engine builders — from weekend hot-rodders to professional racers — keep coming back to the brand.

One-Kit Confidence

Eagle Specialty Products produces high-strength connecting rods and crankshafts for racing engines, and also provides full rotating assemblies including crank, rods, pistons, rings, and bearings for many popular engine combinations. Rather than sourcing each component individually and hoping everything plays well together, Eagle's kits are engineered as a matched system — a meaningful advantage when tolerances and material compatibility are critical.

Tiered Kits for Every Build Level

Eagle rotating assemblies are offered in three models: street/strip rotating assemblies, Pro Street rotating assemblies, and full competition rotating assemblies. This tiered approach lets builders select exactly the right level of strength and material quality for their intended use.

• Street/Strip: Eagle Street and Strip rotating assemblies consist of name-brand quality components for a wide range of engines at an affordable price, and feature a crankshaft, pistons, piston rings, rod and main bearings, and connecting rods.
• Pro Street: The next step up is the Pro Street assemblies, which feature a forged 4140 steel crankshaft, forged 4340 I-Beam rods, and either hypereutectic or forged pistons.
• Heavy-Duty / Competition: Equipped with a forged 4340 center-counterweighted crank (when available), forged H-Beam rods with ARP 2000 or L19 bolt upgrades, and purpose-built heavy-duty pistons designed for high boost levels or heavy nitrous.

Premium Components Throughout

Most assemblies are available balanced or unbalanced if you prefer your machine shop to handle balancing. Along with crank, rods, and pistons, every assembly includes bearings from either King or Clevite and rings suited to the intended application. Externally balanced assemblies balanced by Eagle will also include a harmonic damper and flexplate (or flywheel for some Fords) from Pioneer.

Eagle has several different variations of 4340 steel crankshafts, all of which are nitrided to provide a very hard surface for superior wear resistance. This nitriding process dramatically extends crankshaft service life under the high-rpm, high-load conditions that performance builds routinely see.

Industry Leadership Backed by Continuous Improvement

Continuous design improvements and improvements in materials and manufacturing techniques have resulted in Eagle being the largest and most respected aftermarket connecting rod and crank manufacturer in the industry. Eagle connecting rods, rotating assemblies, and crankshafts are found in everything from serious street cars to hot street/strip cars, to all-out drag, oval, and road racing engines.

Whether you're stroking a classic small-block Chevy, building a Ford 408, or upgrading a modern LS platform, Eagle's rotating assembly kits offer a factory-assembled solution with race-proven components — all from a brand that has been setting the standard in aftermarket engine internals for decades.