In Reply to: Re: Setting points - 8N 6cyl Funk posted by Jack - Iowa on August 20, 2018 at 11:34:03:
"If all is in order, once you get the Gap set correctly the Dwell will fall in place. The two are directly interrelated."
Correct but somewhat misleading. For those that don't know it is dwell and not point gap that is important for proper ignition/combustion. Setting the point gap is simply an easy approximation for obtaining the initial dwell. As distributors and associated components wear that approximation becomes less and less accurate. In "the good old days" you started by setting the point gap and then measured the resulting dwell with a meter. If dwell was off you "tweaked" the gap until you obtained the proper dwell. That was a PITA iterative process that you could do by hooking up your meter while the cap and rotor were off and cranking the engine with the starter. Or you could put the cap and rotor on, start the engine, and measure the dwell. If off pop the cap, tweak the gap, and repeat as needed. Not the most desirable solution and GM addressed it by adding an externally accessible "dwell adjustment window" to their distributors. It made it easy to "tweak" the gap and obtain the correct dwell while the engine was running by using an allen key inserted through that window. Once you had dwell dialed in you then adjusted timing.