Accounting for preheating time, you could fire 3-4 pizzas in the first hour. Maximize your pizza output by having your dough prepped and ready to fire! Pi can run for as long as 3 hours when wood-firing your pizza, depending on how much ash collects in the ash pan. Once the ash pan is full, the pizza party is over. When gas-firing your pizza, Pi can run for as long as your propane tank still has fuel.