BC5759 – Audi/Lamborghini 5.2L V10 Crankshaft – EN40 Billet – 92.8mm Stroke

The Apex of V10 Rotational Assembly Engineering: BC5759

In the realm of high-strung, high-displacement ten-cylinder engines, the crankshaft is not merely a component; it is the foundational backbone upon which power, reliability, and rotational harmony are built. The Brian Crower BC5759 Billet Crankshaft represents the culmination of advanced metallurgy and precision CNC machining, engineered explicitly for the Audi and Lamborghini 5.2L V10 powerplant. Crafted from premium EN40 Billet Steel and featuring a critical 92.8mm stroke, this crankshaft is the definitive upgrade for builds targeting elevated horsepower thresholds, forced induction applications, and extreme RPM stability. It transforms the inherent potential of the 5.2L FSI and L539 engines into a reliable, repeatable reality, making it the centerpiece for professional race teams and discerning engine builders who refuse to compromise on integrity under load.

Material & Manufacturing Superiority: EN40 Billet Steel

The choice of material separates a factory-style replacement from a true performance component. The BC5759 is machined from a single, solid bar of EN40 (ISO 683-11 34CrNiMo6) alloy steel, a nitride-grade material renowned for its exceptional core strength and superior surface hardness. Unlike forged cranks which follow a grain structure, the billet process allows for optimal grain flow orientation throughout the entire part, eliminating potential weak points. This billet foundation is then subjected to a precise heat-treating and nitriding process, creating an immensely hard outer surface for wear resistance while maintaining a ductile, shock-absorbing core. This combination is paramount for resisting the torsional flex and bearing loads encountered in turbocharged, supercharged, or high-RPM naturally aspirated environments. For a deeper technical understanding of billet versus forged manufacturing, refer to this authoritative resource on crankshaft material science.

Key Engineering & Performance Benefits

• Unmatched Tensile & Yield Strength: EN40 Billet Steel provides a significant safety margin over OEM and common forged alloys, crucial for preventing catastrophic failure under peak cylinder pressure.
• Optimized 92.8mm Stroke: Maintains the factory displacement for class legality or provides a perfect foundation for over-square builds with larger bore sizes, preserving engine harmonic characteristics.
• Precision Micro-Polished Journals & Radii: Every journal and fillet radius is meticulously finished to a mirror-like surface, reducing friction, improving oil film stability, and dramatically increasing fatigue life by eliminating stress risers.
• Internal Cross-Drilling & Chamfering: Oil passages are professionally cross-drilled and thoroughly chamfered to ensure maximum oil flow to critical main and rod bearings, even at sustained high RPM.
• Fully Counterweighted & Balanced: Designed as a neutrally balanced component, it arrives ready for final external balancing with your specific rotating assembly, ensuring smooth operation across the entire powerband.
• Direct OEM Fitment: Engineered to drop into the factory block location using standard main bearing sets, simplifying the installation process for a complex component.

Technical Specifications & Dimensional Data

The following table details the precise technical specifications of the BC5759 crankshaft. These dimensions are critical for engine builders calculating compression ratios, piston selection, and clearances.

Complete Vehicle Fitment Guide

Direct Application & Compatible Models

The BC5759 crankshaft is designed as a direct, precision-fit replacement for the factory crankshaft in the following vehicles. It is compatible with both standard and performance bearing sets and is ideal for original block builds, sleeved blocks, or aftermarket block applications.

Audi: Audi R8 5.2L FSI (Type 42/TR), Audi S6 (C6) 5.2L V10, Audi S7 (Sportback), Audi S8 (D3) 5.2L V10.
Lamborghini: Lamborghini Gallardo LP560-4, LP570-4, LP550-2 (all 5.2L L539 engine variants), Lamborghini Huracán LP610-4 (early 5.2L platforms).

Note: Always verify engine code and specific year/model compatibility. This crankshaft is intended for use with performance connecting rods and pistons designed for the 92.8mm stroke.

Installation Considerations & Build Philosophy

Installing a component of this caliber requires meticulous attention to detail. The block’s main bearing bores must be aligned and measured for perfect geometry. It is imperative to perform a final external balance of the entire rotating assembly—including this crankshaft, specific flywheel/flexplate, harmonic damper, rods, pistons, and pins—to achieve optimal NVH characteristics. The BC5759 is the cornerstone for builds routinely exceeding 800+ horsepower and 9,000+ RPM, where the immense centrifugal forces and combustion pressures demand absolute component integrity. It is not merely an upgrade; it is an essential investment in the longevity and performance ceiling of your 5.2L V10 project, ensuring the rotating assembly remains the most reliable part of your high-horsepower equation.