Originally Posted by sandifer
"Slow rolls" even at RV roll rates are fast enough that an inverted oil ball valve has insufficient time to properly reseat and redirect oil pressure under negative G before the roll is finished, so you really don't need to worry about that. Inverted oil is primarily for sustained negative G oil pressure, not negative G transitions. Preventing a little oil from pumping out the breather during brief negative G transitions is another matter. I agree w/ Danny's post above, however a full inverted oil system does allow you to expand your flying should you eventually want to do more. Acro can be addicting.
Any tips on the breather issue? I noticed that the "slobber tubes" on the Great Lakes planes that I got to fly for my introductory aerobatics lessons last winter made a lot of "slobber" after the inverted lessons, so I inferred that the inverted system kept oil going to the engine but didn't keep it off of the belly of the plane (without help from the tube to the tail, that is).
Talk about addiction...I had 10 hours of aerobatic lessons in December and I'm still twitching for more. But until the RV is flying, the only plane I have that is remotely capable of aerobatics is a J-3 Cub and...well, the advice I am getting on that is that, if you have to ask the entry speeds for loops and such, you shouldn't do them, and I have to ask. So I have been constrained to the boring old Normal Category for months now. I will say that I didn't get addicted to sustained inverted flight or inverted spins, but I would really enjoy a hammerhead right about now!
I'm now torn on the inverted oil system. Probably the right thing to do is finish the 14 and fly it a thousand hours without sustained inverted flight and, if I need more, build an RV-8 or buy something already set up for such foolishness.
For now, I'm shopping for oil accumulators and information on how to get them hooked up to an IO-390.