The connecting rods are pretty durable, and if one failed, you would hear noise. And vibration if it broke and was thrashing around. When you did the compression check, did that cylinder should have sounded much different from the others- that is to say, no 'compression' sound. The broken piston is becoming more likely. If the head broke away from the skirt and stayed at the top of the cylinder, as it might under ring tension, you might not hear any noise; unlikely, but possible. The same condition you found with your Ford, but without the valves hitting the piston, and without the piston pieces banging together. This is all speculation so far. But at least, your compression gauge is working...
Harvester
