More like 10,000 hours. Seriously, three compression rings plus oil control? Cast iron heads WITH valve seat inserts and bronze guides? The wrist pin bushing is even full pressurize lubricated with the connecting rod gun drilled from the large end. Of course this also cools the piston.
The weakest link is the injection system, worn cam lobes or button wear can retard timing, this slightly reduces efficiency. Fatigued springs in the injectors can reduce spray efficiency. All of this can be fixed.
One key of engine life, aside from proper PMCS, is engine loading. Aircraft reciprocating engines operate most of their life producing 75% of their rated power, usually for 1500 to 2000 hours. They do it producing 1/2 Hp per cubic inch of displacement at 2500-2800 RPM
These MEP-002A/003A engines have 35 cubic inch cylinders and each cylinder produces only 5 Hp at rated output. Sure, it is at 1800 RPM but it is also diesel which means higher cylinder pressures. But the specific output is 3-1/2 times less than an aircraft engine. Which means these engines should last at least 3-1/2 times as long as an aircraft engine or 7000 hours. But engine life isn't linear, 10,000 hours is still conservative. Again, proper PMCS.
Now, about the actual output of a 002A's engine. The TM lists the rated power at 8.9 Hp at rated output of 5 kW. In reality, Onan rated the engine at 16.5 Hp. Quite a difference between actual and rated.
Now, this isn't a suggestion you run them at twice the rated output. Doing so will reduce the life of the engine.
