Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.
Advance and Retard:
This refers to the change in ignition timing that is made through both mechanical and vacuum systems to allow for different combustion situations for different rpm and smaller or larger throttle openings. The mechanical system advances the ignition as rpm increases to allow for the decreased time for combustion.