Well, it looks like I fixed the air leak in my engine. Then I had to get the engine back tuned in from when it was leaking. Got the engine just right in the practice before the A-main. Running strong and FAST at 224 degrees, then.......

....baaaaaaaaaaa....<doing my best engine noise sound>......POP! Engine stopped instantly. Took the manifold off to get a peak at the inside and the flywheel and shaft is moving but the piston isn't...Ouch!

Haven't disassembled it yet, but my guess is a broken rod.