The Stovebolt Site Forums The Shop Area Engine Shop Ignition advance question

I think Jery answered your question in a slightly different way. He referenced several times the peak torque RPM/ignition advance/throttle opening balance. If you have achieved peak torque at a certain RPM with 32 degree advance, and one more degree of advance actually hurts the torque output, you have gone too far with advance. Torque is the goal, if you light the fire too soon it will effectively try to push the piston backwards down the cylinder and drastically hurt the torque/hp/economy/drivability/engine longevity. Ignition "ping" is the sound of the explosion rattling the piston assembly, it can and will destroy the piston. No doubt the manufacturer wanted to get as much performance as they could but they also wanted the engine to live a long life, that is where vacuum advance comes into play, it increases advance only when the engine can allow it without damage. P.S., my '57 2 ton truck with the original 283 has no vacuum advance, only centrifugal. They understood that it would be used for heavy work and most likely would not see much part throttle high vacuum use. The centrifugal/vacuum governor limits the RPM at 4000, static timing is 4 degrees, I didn't look up the total advance but it probably was on the safe side so as not to burn holes in the pistons or bend the rods, they wanted the truck to live forever under heavy load.