Here is a hint:
1) Air/fuel mixture in a chamber
2) Spark
3) Air/fuel mixture ignites by the spark plug, and progressively ignites the rest of the chamber mixture as the flame front travels.
It doesn't matter if the original spark that gets this going is bazillion times more powerful than it needs to be, it makes no difference at all to Hp.
Why should it? It's not the size of the wick on a dynamite that matters, it's the size of the dynamite itself, as long as the wick works well enough to get it to activate in the first place.