Ramcharger - Ultimate Tune-Up

Mechanical, or centrifugal, advance is controlled by weights and springs. As the distributor shaft spins, centrifugal force tries to pull the weights outward. Springs of varying strength hold the weights and keep them from moving at slower rpm's. As speed increases, the centrifugal force overcomes the springs, allowing the weights to move and change the position of the rotor with respect to the cam. (B) Centrifugal advance can be tailored by adding different weights, by swapping lighter or heavier springs, or both. Our lighter primary spring looked good, but our heavier secondary spring was too strong. It kept the advance from coming in soon enough. (C) MacNeil swapped secondary springs until he found one that allowed for 20 degrees of mechanical advance at 4,000 rpm.

If you would like to have your distributor recurved and can provide your engine's compression, cam specs, engine size, and how your vehicle is used you can mail your distributor to The Dyno Shop. They will recurve it using your information and ship it back to you ready to be installed.

Dynos Don't Lie
As you can see by the following graph and chart, we saw increases in all areas. Check out the impressive increase in lower rpm torque!