I had a friend who owned a Taylor Craft airplane, a two seater fabric plane, tail dragger. I flew with him one weekend scouting roads over my deer hunting area in southern Arizona. The exhaust manifold bolted to the block was the only support for the manifold and short exhaust pipe. The next time he flew it, he was in final approach at Tucson International Airport, and when he throttled back, the plane started to vibrate and shake so severely, he felt it necessary to shut off the engine to keep the thing from shaking apart. He landed safely without power.
Upon inspection, they found a crack in the exhaust manifold from the stress of the unsupported exhaust pipe and an exhaust valve had cracked. They speculated that cold air hit the valve when suddenly throttled back. I believe they fabricated a support for the exhaust pipe to keep it from happening again.
Kent
