ORIGINAL: Grrrrrumpy
mount the engine right side up to prevent the fuel from siphoning out (a hole in the top of
the cowl won't be all that bad)
I don't know about others, but I just haven't seen the problem of fuel siphoning out. My engine is mounted inverted (Saito .91) A have a small loop of fuel tubing from the tank to the fuel nipple. It sort of goes up, the ndown to the carb. No leakage that I've seen, at all. But, if you feel like it, try putting in a fuel filler valve and when not flying, insert the filler probe into the valve. Someone else mentioned this a while ago. It should solve the problem, and your UCD will still look good.