cmaurice876

I was reading through the "ignition 101" thread and I understand most of it.

My main question is why would some factory engines be set at 0 degrees of timing? If the lpp is usually 14 degrees ATDC, wouldn't every engine need to be advanced to some extent to make the pressure greatest ATDC?

Also can someone explain how the Air to fuel ratio is related to the ignition timing? Or what an optimal situation would be?

Thanks alot

eallanboggs

iTrader: (1)

The spark has to get there early because of piston speed. If it is too late(0 advance) there isn't enough time for the charge to burn completely before the ex valve begins to open and the EPA doesn't like it when that happens.