A happy Labor Day to all my gearhead bros/broettes. I’ve spend the last hour or so on YouTube watching motor videos and can’t wrap my noggin around this one question. If the fuel/air charge explodes during the power stroke why would the exhaust stroke be so loud? All that’s happening is the piston pushing out spent gases right? What generates the exhaust noise? And why do you see flames popping out of short-stacked motors? Is it just unburnt gases igniting in the exhaust?

McLaren M8C for your viewing pleasure.