ZRP Connecting Rods for Honda B18A / B18B / B20

H-beam connecting rods for Honda B18A/B18B/B20 engines are manufactured from 4340 high-tensile steel and designed for high performance and extreme durability. Their lightweight design combines optimal performance with proven reliability at high RPMs. The bushings are made from aluminum-silicon/bronze and feature a radial groove that acts as an oil reservoir. These connecting rods have a grooved pin end that minimizes deformation under high inertial loads, thereby reducing weight. They undergo shot peening to relieve material stress and a multi-stage heat treatment to increase rigidity. Strict production process tolerances ensure a perfect fit and optimize oil clearances. Flexing and twisting are strictly controlled. Each connecting rod includes 5/16” ARP 2000 cap fasteners with a 220,000 psi tensile strength. Optionally, 280,000 psi ARP Custom Age 625 material can be purchased as an upgrade. The complete kit includes ARP Moly lubricant and comprehensive assembly instructions.

Additional machining processes:

Dowel sleeves for perfect fit and precise reassembly.

Cap relief for greater big end integrity in extreme applications.

Thrust face grooves to reduce weight.

ZRP connecting rod technical features:

Two-piece forging for high strength.

Shot peened for increased fatigue life.

Aluminum-silicon/bronze bush with radial groove.

Magnaflux inspection ensures forged material consistency meets our high quality standards.

Double ribbed caps for extra support.

Multi-stage heat treatment for maximum strength, dimensional stability, and fatigue life.

CNC machined for superior tolerances, accurate to 0.0002”.

Center-to-center distance is maintained under pressure. 0.001" tolerance

Finite Element Analysis (FEA): Computer-generated stress analysis for connecting rods

Optimal balancing for weight-matched sets of ± 1 gram