Related Photo Galleries
The lines on this Ford block trace the oil galleries that Ken Troutman of KT Engine Development mentioned. For all the other main bearings, oil flows in one hole and out another that leads to that main's corresponding cam bearing. Because of the horizontal gallery cut into the front of the block, the front main is fed from two holes. KT Engines plugs the leftmost hole and allows oil to feed directly to both the first main and cam bearing through the other gallery.