Keep positive
cjensen said:
I think I'm gonna go carb.
Good plan. All my aerobatic RV time is with a Carb.
Besides all the positive stuff everyone mentioned you can do zero G stuff like hesitation rolls or extending an inverted down line or floating over the top of a loop. Positive G's by definition is anything above zero. Example 0.3 G's gives you a semi-weightless feeling, but enough to keep the engine fuel and oil basiclly where it belongs. I found the more aggressive I approached zero G's the more oil I got on the belly, but that was it.
Anything right up to zero is fine, but intentional continuous negative is a no no. However an occasionally jump on the negative side momentarily will not cause ill effect, except may be the engine will stumble momentarily and more oil on the belly. Continuous negative G's major issue is oil pressure.
To be clear it is very easy to do LOTS of aerobatic maneuvers and keep positive G's.
If you become an aerobatic monster or expert you'll out grow positive G maneuvers. I have seen that happen a few times with friends. There's a few ways to get your negative G acro fix satisfied. Install inverted fuel and oil systems in your RV or get an aerobatic plane. The latter option is doable with a club or group going in on buying a dedicated acro plane. I know a bunch of RV's that went in on a Zlin-50. It's easy to maintain and has a Lyc engine. It's a better acro plane than a RV. It works well in a partnership since you usually only fly it 20-30 minutes at a time.
Lets say you get into IAC competition down the road, the entry level is the sportsman category. It's a pos-G class, but you almost need to fly negative G's to be competitive so I am told. I never competed but a buddy did in his RV-4. One required maneuver I recall was an inverted 45 down line. The longer you hold it the better. Its hard to do with positive G's. However it can be done. Your engine might cut out momentarily, but it will roar to life when you flip over again; its kind of exciting to watch and hear you engine cutting out and back in. Many Piper Cubs or Citabria's fly this class with their engines cutting in and out. Frankly the RV is not great for competition because its fast, and staying in the "box" is a challenge. I was lucky to be taught Acro in a Stearman. I remember the engine coughed and stumbled a lot while I was learning.
Obviously oil pressure is critical. Ask an engine expert what affect a momentary oil P drop has. Its may not be ideal, but we're talking about a momentary drop. I have heard of more engines w/ inverted oil systems getting toasted (ruined) when the system failed or stuck.
Bottom line there's a ton of fun you can do on the positive side of zero G's, not involving competition, which is fun, safe and easy to do (with some basic training). There's no need to fear an inadvertent excursion onto the negative side. It's easy to fix, pull on the stick a little or roll upright. With practice you can fly the exact G's you want by seat of the pants, but highly recommend you have a G's meter in any plane you intend on doing aerobatics in.
Most are quite happy on the positive G side, including me. Also RV's are not really that great for extended inverted flight and fly due to the airfoil. You need a lot of positive (negative?) angle of attack to fly which is draggy.
You will have endless hours of Acro fun if you are just starting out. If I am solo I try to roll and loop at least once every flight if possible. If you get to an advanced or expert level you can deal with the inverted stuff later. I am still trying to get good with the positive stuff. I would like to buy a pure Aerobatic plane with partners. I just could no justify the cost and weight for the inverted oil system and switching to Fuel Injection or Ellison TB for my RV.
