Your engine should be fine in a standard .40 trainer.

The silicone tube won't melt by just touching the crankcase of the engine, maybe if if was in direct contact with the cylinder head. It might get worn down by vibrations though, try to avoid contact if you can, but its not a big deal if you keep an eye on it and change it before it starts to leak. The consequence is that the engine stops and you spill fuel all over the plane, it won't catch fire or anything worse.