ZRP Connecting Rods for BMW M5 V8 S63B44 HD Series I-Beam

I-beam connecting rods for the BMW V8 M3 S65 4.0L engine are made from the highest quality 4340 high-tensile steel, with a shape specially optimized for high performance and extreme durability. They feature a straight-cut pin end for increased durability, meaning they should only be used with aftermarket pistons. The bushings are made from AMPCO 18 material, which offers excellent wear and fatigue resistance, and have a radial groove that acts as an oil reservoir. They undergo shot peening to relieve material stress and multi-stage heat treatment to increase their rigidity. Strict tolerances in the production process ensure a perfect fit and optimize oil clearances. Bending and twisting are strictly controlled. Each connecting rod includes ARP 2000 head bolts with a strength of 220,000 psi; optionally, ARP L19 material with a strength of 260,000 psi can be purchased. The complete kit is supplied with ARP moly lubricant and comprehensive assembly instructions.

Additional machining processes

Straight-cut pin end – suitable for aftermarket pistons

Dowel bushings for a perfect fit and precise reassembly

Flanged cap relief for increased connecting rod head integrity in extreme applications

Thrust face grooves to reduce weight

ZRP Connecting Rod Technical Features

I-beam shape for increased rigidity

Two-piece forged for high strength

Shot peened for increased fatigue resistance

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

Double rib caps for increased support

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

CNC machined for superior tolerances, accurate to within 0.0002"

Center-to-center distance maintained within 0.001" tolerance

Finite Element Analysis (FEA) – computer-generated stress analysis of the connecting rods

Optimal balancing for weight-matched sets to within ± 1 gram