Carrillo SCR4879-4 Pro-SR Straight H-Beam Connecting Rods

Manufactured in the USA, these rods are precision-machined from CP-Carrillo's proprietary Carrilloy 4330M alloy steel — a chrome, nickel, moly, vanadium alloy that meets all VAR (Vacuum Arc Re-Melt) ASTM standards — delivering an exceptional combination of strength, toughness, and fatigue resistance.

Key Features:

• Straight H-beam design engineered for extreme inertia and cylinder pressure loads
• Forged from oversized proprietary Carrilloy 4330M steel blanks to ensure correct grain flow and eliminate surface inclusions
• Heat treatment produces a UTS of 195,000 PSI and yield strength of 182,000 PSI with low notch sensitivity
• Each rod is magnafluxed at least twice and Rockwell hardness tested to validate heat treat integrity
• Final 200% shot-peen operation converts surface tensile stresses to beneficial compressive stresses for extended fatigue life
• Precision CNC-machined with probing systems to validate dimensional integrity
• Each rod laser-etched with a job number for full production traceability

CP-Carrillo connecting rods are available with two fastener options: the standard WMC (H11 Tool Steel) bolt rated at 220,000 PSI UTS, or the upgraded CARR (MP35N Multiphase) bolt rated at 285,000 PSI UTS. Each fastener features a patented asymmetrical thread design for maximized clamp load and fatigue life. CP-Carrillo recommends the bolt stretch method over torque tightening for the most consistent and accurate preload.

Built in CP-Carrillo's state-of-the-art manufacturing facility in Irvine, California, the SCR4879-4 represents decades of race-proven engineering, trusted by professional engine builders across drag racing, road racing, endurance racing, and high-performance street applications.