Pinned Mains + Line Boring for EJ

Main Bearing Support & Alignment Upgrade

High-powered Subaru engines often suffer from the main bearing tunnel becoming out of round under increased cylinder pressures. To combat this, CJM’s machinists install precision alignment pins that lock the main bearing journals in perfect position, maintaining structural integrity even under extreme loads. In addition, ARP case hardware is used to ensure even clamping across the case halves, improving main bearing support and longevity.

This CJM machine shop service can be added to any engine build, providing enhanced reliability and strength for both street and competition applications.