Fuel Starvation

I have owned N12HR for about 6 months. It was built in 1991. It has o 320 with carburetor.
After about 10 hours, the aircraft feels very reliable.
I pulled the nose to about vertical and allowed the nose to fall into the left wing. Fuel selector was on the left tank. Boost pump was off. As the nose began to move toward the horizion with the left wing low (to prevent negative loads) the engine quit. I pushed the nose down to keep the propeller windmilling. The engine restarted after a few seconds. I was surprised by the interuption in fuel. I always allow the aircraft to fall through an extreme nose high attitude by rolling a wing low.
Any thoughts?
Thanks

It?s got a carburetor.. this sounds pretty normal. I believe it?s from low ?G? or sideways ?G? sloshing fuel from the main jet in the float bowl. Pretty nice actually, because the oil is probably doing the same, so the engine quitting at that moment is removing power while oil pressure is probably fluctuating.

That's normal in my experience with my Carb'd -4. When doing hammerheads, if I go slightly past vertical on the upline, therefore inducing a slight negative loading, the engine will let me know right away...

Thank you both for your insight. I wasn't sure if it was a fuel system or a carburetor issue.
Does this occure during aileron rolls also?

Our RV-6 has an aerobatic tank on the right side. There?s a flop tube and a small hopper inside the main tank. When doing aerobatics, I always select the right tank and turn on the electric fuel pump even though our engine is carbureted. Any negative g makes the engine very quiet but at least I know there?s fuel going to the carb and power comes back quickly as soon a g goes back to positive. I don?t fly around inverted for a few reasons but I do see a bit of negative g now and then, like when I get a bit past vertical on a hammerhead or float the top of a loop too much. The engine quitting is not alarming. The carbureted engine starts right back up.

GHARBEN said:

Thank you both for your insight. I wasn't sure if it was a fuel system or a carburetor issue.
Does this occure during aileron rolls also?

Click to expand...

With a carb., the engine will quit anytime the airplane isn't in a positive (at least slightly) G condition. The design concept of a carburetor is that it be exposed to normal (positive) G loading. They work fine with more than 1 G.

So if by aileron roll you are talking about a roll about the longitudinal axis with little to no altitude or pitch change, yes the engine will quit because that type of roll can't be done without some negative G's.

There are a lot of alternative roll maneuvers that can be done with a carburetor though.
One example would be a barrel roll.... the entire maneuver is done at 1 G.

Thank you Scott
I truely enjoy the RV. Although I have many years of flying, my acrobatics have been limited to spins, loops and hammerhead stalls. I will get some training on barrel rolls and such. Thanks for your help.
G Harben