After four what I would call "textbook" flights on my B-24, flight #5 ended with #1 engine coming to a stop in flight. I had made a couple low passes across the field, reclimbed to altitude and turned downwind, parallel with the runway, when about halfway through the downwind flight the plane suddenly went out of trim, with a significant "left yaw". It was easily stopped with a little right aileron, but when I let off it immediately went back left. (I have rudder coupling mixed with ailerons) My first thought was that I had lost an engine, but I expected a more violent reaction from the plane. In any event, I dropped the gear and made an uneventful landing, during which I didn't even notice if the prop was stopped or not. One of the members was video taping the thing, and I had him run the tape back and sure enough, the prop was stopped when I crossed the threshold.

2nd flight: After checking everything I could think of, re-adjust the engine, do another vertical test, etc., I decided to do another flight. After take off, I began a turn away from the runway while climbing. About the time I had completed a 180˚, the airplane started a very pronounced left roll. I managed to get it stopped, but was still trying to maintain altitude or even gain some. Problem this time was that I was low on airspeed and climbing when the engine quit.
Short story, I struggled, but managed to get it back to the field in one piece, much to the surprise of some others who were watching the entire thing!

Question is, why 4 near perfect flights and this crops up. Best thing I can come up with is fuel foaming in the tank. The tanks are in the outboard nacelles, and there is so little room I didn't think at the time I could get any foam in around the tank, for having to cut deeper into the wing. The tanks for the inboard engines are in the fuselage, and have foam all around them.
Going back over things, it seemed to me that on the first flight, one engine seemed to be awful rich, leaving a lot of smoke. When I mentioned it, my son said he also noticed it. I can't recall which engine it was, but probably was #1.
I am presently working on putting foam around the tank. Does anyone have any other suggestions while I'm into it?? I'm mostly baffled as to how I got 4 good flights before this showed up.
Randy