Is Dorney Park heavy people friendly?

It depends on how much you weigh and your size. It also depends on what rides you want to try. For the most part, Dorney Park has been really good at accomadating people of all sizes and they really try to fit in the family friendly type of thing. Some rides and coasters will fit bigger sizes of people, especially their inverted looping coaster, Talon. In certain rows they have "big boy" seats that are bigger and can accomodate larger sized people. When you get to the park or a specific attraction, I would ask the employee if that attraction would fit you and your size. Have fun!