Damage Detail, Piston + Connecting Rod
Hard to believe that piston is only 1cm across, isn't it? Looks like the "real" thing, ie from a bigger engine. This piston had about 1 gallon of fuel run past it (that's how you measure the life of R/C engines. A well tuned engine needs to be rebuilt after about 10 gallons at the most. This engine had about 8 hours of run time on it when it bit it- far less than normal, but the cause was a rock rather than engine failure due to internal flaws.
\The torn hole at the base of the rod should be a closed circle and should have a brass bushing in it that fills about half the hole. Two small fragments of that brass are visible at the bottom of the picture. The large nick at the top of the piston itself is from a brass fragment that lodged between it and the cylinder wall while the engine was operating. In a real car, that would likely cause the engine block to fracture.
Due to the damage to the piston head, I had to throw this one out- it will never fit right again, and even if I can machine it down without ruining it, it will never sustain the high compression level needed to operate these tiny engines. They're relatively cheap, anyway. :)
These are amazingly light things- I would be amazed if they weighed more than 1-2 grams each. You can't even tell the piston is in the palm of your hand if you don't see it.