Can someone explain spark blow-out to me?

[ccwilms]

I have a powerdyne and I always have gapped the plugs a bit lower because I wanted to avoid blowing out the spark. Somehow it seemed obvious that the blower is pumping out this huge volume of air and it can blow out the spark. But now that I think about it, this doesn't make any sense to me. I mean, the air enters the cylinder, then the intake valve closes, and the compression stroke begins. At this point, there is no movement of air either in or out of the cylinder, it's just being compressed to a smaller volume, then comes the spark. So how does this "blow out" the spark? It's not like there's this huge wind rushing past the spark plug when it fires? Then again, I can't deny that too large a gap on a supercharged application definitely doesn't work. I guess I'm just an idiot. Rats.

 

[drudis]

The higher the compression (more boost = more air to compress in the cylinder) makes it harder for the plug to fire.
Thus, after a certain point of boost, you "blow out the plug".
My S-trim went from .052 to .045 to .040 to .038... kept getting smaller and smaller gap. Power kept increasing and not misfiring until I stopped at (if I remember) .038" gap.