I thought that the engine had ripped off the firewall. But others who saw it said that my engine exploded into many pieces.  Anyway I had my hands full with an airplane with no front end.  Of course it pitched up and started its "death roll".  I was able to push the front down with extreme down elevator and level the wings somewhat and manage to make a belly landing with the landing gear hanging from the frontend. Only damage to the airplane was the shattered frontend (pics attached).  This all happened at about 100 AGL.

 Approached the crash site and began searching for engine parts. We found most of them within a 150-foot circle. We brought the engine parts back to the pits and began a triage' & examination of the engine parts. (See Pics) A closer look revealed that the con rod was broken in half.  An even closer look seemed to indicate that the con rod was previously fractured. This fracture was the result of a crash from the previous owner on his 1^st flight.  After purchasing the engine on the internet, I added about 15 – 20 or so flights. 

The engine was purchased on consignment and I knew about the previous crash. But I never tore down the engine for inspection. (Should have been checked for internal damage). The engine was at half throttle when it gave way, the kinetic energy was so strong the prop and spinner ripped & tore the engine case apart, breaking engine into 2 large pieces. The other part of the explosive report was the cowl and nose shredding to a million pieces.

 To tell the truth, I am a bit embarrassed. There are lessons to learn from this incident that others and especially me, did not heed.

Any RC engine... whether small or large should be thouroughly inspected and disassembled after a crash before flying again. The scary part is that this could have easily of happened in the pits on initial engine run up.  Everyone s hould stand behind the airplane when running up the engine !!