seems like a couple too many multi's popping lately..... definitely scary
so what is the main cause? rod/bearing failure?
In my experience, there are only two significant causes of rod failure. Both are frequently the result of abuse:
The first happens when you run the engine out of oil, or oil pressure. The rod bearing will seize and lock itself tightly to the crankshaft causing the rod to shatter from the bending load of the crank trying to push the rod sideways.
The second happens when you over speed the engine. In this case, the extreme force required to reverse the direction of the very heavy multifuel piston quickly, causes the rod cap to stretch. This opens the bearing tolerances to a degree that exceeds the oil pump's ability to fill the bearing space with a cushion of oil, and this newfound sloppiness in the bearing allows the crankshaft to hammer the cap (like a blacksmith) until the cap breaks open and allows piston to drop down. When the piston drops down, it, and or the rod, will get jambed between the moving crankshaft and the crankcase wall.
If the OP was tooling down the highway at an indicated speed of 60MPH, he was over speeding the engine, and could easily have caused the second type of failure. If he has an engine that burns or leaks significant oil, and the sump ran dry, or the oil pump failed, or the oil was old and clogged passageways, the first type of failure is likely.
It is interesting to us to know what was being done to the deuce up to the point of failure. It might save another deuce's engine.
-Chuck