For 1/2A combat, the saving grace of the Cox TD design is that the needle valve would swing back instead of breaking when you stuffed the plane.

Sometimes..maybe mostly, it worked that way.

With a rigidly mounted NVA up front, you have no chance. Your best chance is to fly over a fairly hard field where the engine doesn't tend to get buried everytime you crash.

The Cyclon / Fora revolutionized the sport not just because of the extra power, but the NVA is controlled by a very well tucked in thumb wheel. These are very hard to damage in a crash, plus the notched wheel is very handy for fine tuning when the pressure is on.

The engine in the photo just needs to have the extended lever cut off to make it ready for combat.