Firing each cylinder at the optimum point is critical for engine life and performance. If a cylinder is fired late, itís down in power; if early, it destroys engine components.

If the magneto drive does not keep the magneto (or magnetos) in phase with the engine, you have to set it to fire intentionally late and this avoids ever firing early by mistake. What causes this? Some people think that it is caused by the belt in the magneto drive, but that turns out to be wrong. The problem is that the high inertia in the magneto combines with a flexible magneto drive shaft to create the inaccuracy MSD ís development of higher-inertia magnetos has made the problem worse.

PSI's family of magneto drives has fixed the problem without adding weight, our revolutionary design has increased ten-fold, the stiffness of the shaft, and thereby minimizes inaccurate firing. This single fact allows you to set the magneto at the optimum firing point -incredibly producing up to two hundred horsepower. A side benefit is that using a PSI magneto drive eliminates the need for crank-triggering, and all of the failure-prone hardware that goes with it.

Our drives fit many Chrysler-block applications, and come in both single and dual-mag versions. We can also supply the shaft only if you already have a Sitko single drive or a Dunn single or dual. Each drive shaft is factory set with .002-.004in. endplay, which controls the axial position of the bronze drive gear. The drive gear never contacts the thrust face of the thrust bushing in the block (even when the bushing surface is off location). Installation is simple: our shaft assembly bolts directly into a Sitko housing. The Dunn housing requires minor rework, which you can do with our instructions, or we will do it for you.