This military exhaust manifold does not have a thermal spring operated flapper.
The flapper is set in the position as shown in the photo … or maybe it is designed to be in this position and manually adjusted after the manifold warms up. ?? The flapper and shaft is not rusted in place it does move but not in the full range.
My question: is this flapper design manually opened as the manifold is heated? I am familiar with the spring design but I am unfamiliar with this flap design.
