Russman

My Feedback: (12)

I have a Hangar 9 33% Cap with a Brison 5.8 on it. I have 4 flights on the plane and 3 of them have been "dead stick". Not much fun at a field with about 200 ft of runway. The engine sounds great on the ground but every time I go into an inverted flatspin,it cuts off. Other times after doing waterfalls,etc.,it sounds like it has cut off but comes back. My carb has the inlet partially sticking outside of the cowl. THe pressure regulating diaphram is inside of the cowl. I am thinking this is my problem. I am considering building some kind of inlet manifold and picking up "clean air" inside of the cowl for the carb inlet and tapping my diaphram pressure line into this manifold. I have seen a manifold horn that Cactus Av. sells but this thing would stick completely out of the cowl on my plane. Has anyone done this before? If so,what were the results? Got pics? Thanks.
Rusty

btw I am not new to gas engines.I currently own a GT80,a Quadra 42 and Quadra 75 in addition to the Brison. This is the first time I have ever run into this. All of my other engines have been flawless.

GeraldRosebery

My Feedback: (14)

I think you are probably right about why the engine quits. It is being starved of air from the maneuvers you state are a problem. In a fast flat spin (I assume it's fast) the angular momentum of the spinning motion of the airframe will tend to want to eject air from the venturi. Combine that effect with a venturi that is exposed to high velocity (low pressure) air in the spin and the engine is being starved of air at an idle setting when suction is so low.

Getting your air inside the cowl will probably help. Also install a velocity stack to "organize" the inlet air if you don't already have one.