Carrillo SCR4247-4 Pro-H Beam Forged Connecting Rods Honda K20 3/8" CARR Bolt

Key Specifications:

• Rod Length: 5.590 in / 142.00 mm
• Big End (BE) Bore: 2.1666 in / 55.032 mm
• Big End (BE) Width: 1.020 in / 25.91 mm
• Small End (PE) Width: 1.000 in / 25.40 mm
• Pin Diameter: 22 mm
• Gram Weight: 600g total / 428g rod / 172g cap
• Bolt Size: 3/8" CARR proprietary fastener

Pro-H Beam Design & Material:

• Manufactured from Carrillo's proprietary Carrilloy — a chrome, nickel, moly, vanadium alloy meeting all VAR (Vacuum Arc Re-Melt) ASTM standards
• Heat treated via a mar-aged operation achieving 195,000 UTS with a yield of 182,000, while maintaining low notch-sensitivity and ductility
• Forged from oversized blanks to ensure proper grain flow and eliminate surface inclusions
• Rated at 275 hp per cylinder, allowing a 4-cylinder engine to safely support up to 1,100 hp

Quality Control:

• Each rod is magnafluxed twice during production to detect any surface flaws
• Every piece is Rockwell hardness tested to validate the heat treat procedure
• All critical CNC machines use probing to validate dimensional integrity
• Final shot peen operation improves fatigue life by inducing beneficial compressive surface stresses
• Each rod receives a laser-etched job number for full traceability

CARR Bolt Fastener System:

• Includes proprietary 3/8" CARR bolts — a significant upgrade over standard ARP2000 fasteners
• Asymmetrical thread design distributes engagement evenly, increasing clamp load and fatigue life
• Available in H-11 tool steel (220,000 UTS) or Multiphase MP35N (285,000 UTS) options

Carrillo's Pro-H connecting rods are manufactured in the USA and are trusted by professional engine builders and racers across drag racing, road racing, oval track, and endurance competition. The SCR4247-4 is a direct-fit solution for the Honda K20A2, K20Z1, and K20Z3 engine families.