I just read somewhere that continental is no longer using those connecting rod castle nuts with cotter pins and instead they use a spiralock nut, a locking nut with no pin. The pins were shearing off and were found in the oil sump possibly doing some damage to engine internals. I just rebuild my car engine (doesn't use castle nuts and pins just a squished nut) and the first thing that came into my mind would be broken cotter pins in your engine. What a strange design in an airplane engine where you are trying to eliminate any parts that can break off under stress. I'm now rebuilding my car transmission because of a broken torque converter at 130K miles. Bunch of small metal parts inside and luckily none of them made it thru the oil passageways back into the transmission. I also had to disassemble and clean the valve body and all 16 valves just to make sure no small particles would prohibit the valves from moving.
