PER PLUS mechanical (fixed) lifters are manufactured from high-quality hardenable iron alloys to withstand design stresses and normal engine contamination. Material and design excellence provide lifters that are lightweight, yet exhibit superior strength, and a patented oil metering system limits the amount of oil that reaches the overhead. This keeps as much oil in the crankcase as possible, while still providing adequate lubrication to the overhead. Their heat-treated pushrod seats are used to eliminate wear from pushrods in racing engines with high valve spring pressures