xray328,
Ideally you don't want the tubing rubbing against the engine, but it's not going to hurt anything if it does. The temperature isn't the problem because the heat from these motors don't even come close to affecting the silicon tubing. If there is anything to worry about it would be rubbing through the tubing, but I wouldn't even worry about that too much either. It's going to take a lot of airtime to rub through, and I mean A LOT of time. More than any of us will fly in a year!!!

What you have in your picture will be just fine. Don't worry about it and have fun flying!!! [8D]

Ken