entry speeds / how to do.... basic aerobatics Waiex?

[Rynoth]

I haven't had any engine issues yet during aerobatics. Aerovee Turbo with a stock 2.5 needle in an Aeroinjector. Started all my maneuvers with mixture leaned for max-continuous power cruise flight. I don't have a fuel flow meter, I do have a gascolator.

[Sonerai13]

1. Have any of you guys experienced engine flooding out doing acro? If so, what did you do to cure that problem?

Yes. Most all throttle body injectors like we use on the VW conversions (AeroInjector, POSA, etc.) will go rich due to the g loading during a high G maneuver. I had a POSA on my Sonerai and did acro with no problem. Same with the Sonex and Onex. I have never had one go so rich as to kill the engine though. Had a couple of stumbles on occasion, but was expecting them so didn't get worried.

As others have mentioned, leaning to best mixture for the altitude will minimize the issue.

2. Is installation of a fuel pressure regulator necessary?

In my experience, no. As always, YMMV, but on all the airplanes I've flown there was no problem doing acro with the AeroInjector (or the POSA).

[Fastcapy]

Questions: 1. Have any of you guys experienced engine flooding out doing acro? If so, what did you do to cure that problem?
2. Is installation of a fuel pressure regulator necessary?
3. If it is, would it be ok to weld a bracket to the motor mount (cross piece going side to side) to hold the regulator?

Any input you guys have would be appreciated. I am getting too old to keep waiting for my acro fix.

Yep, I experienced it multiple times when pulling positive G loads. Engine would go way rich and sputter. Luckily a quick push over kept it running. I also realized that was the cause of the stumble I experienced on takeoff. With the fuel pickup at the rear of the tank the rearward fuel movement and increased head pressure would cause it to go rich and "burp". Dangerous, but hey just fly through it they say...

I tried an Aeroinjector and then an Aerocarb and both had the same issues. I finally bought a Rotec TBI and have not had an issue with it since. I actually feel comfortable flying behind it now. With the aeroinjector/carb I felt like the motor was going to quit at any minute. Best thing I ever did for my plane was throw the aeroinjector/carb in the trash.

[sonex1374]

I fly acro often and my AeroInjector handles the G's well. Like Joe Norris and others have reported the mixture may temporarily enrichen, but if I'm leaned appropriately for my altitude it's an insignificant effect. I'll try going to full-rich next time and see how that affects the engine. I'm very happy with the AeroInjector, but I don't have any experience flying Sonex acro with anything else either (e.g. Rotec TBI, Ellison, Zenith Carb, Bing, EFI, etc.... so many choices!)

Jeff

[gammaxy]

My experience is similar to Jeff's. I adjust the mixture lean for smoothness while gently pulling G's during the clearing turn and find the mixture to be fine throughout aerobatics. Otherwise, it will bog down.

I had a fairly regular stumble like Mike's on takeoff and when applying power rapidly to end a descent. I ended up training myself to advance the throttle slowly to avoid it. I decided to try out the burp tube others have mentioned and haven't had a stumble since. My theory was vapor bubbles were in the fuel line and the engine was going lean, though. The one big catch is I definitely want to shut off the fuel with the fuel valve (and wait a while for the engine to shut down) or else the entire contents of the burp tube will slowly drain through the Aeroinjector after shutdown.

[mike.smith]

FWIW, I've never had so much as a hiccup flying acro with the AeroInjector. The engine RPMs may slow a bit when I get closer to 0-g's (lower head pressure), but other than that I've never had a burp or stumble. It runs the same a 4.5 g's as is does at 1g.

My acro involves, aileron rolls, 4 point rolls, loops, spins, Cuban 8's, hammerheads, and variations thereof.

I've also rolled a Waiex with a Viking engine (thanks, Max!). No issues there, either.

[gyroron]

I went up the other day, climbed to 5000 feet, and did several rolls, a few split s, steep turns, etc... just couldn't get the courage to do a loop. Not sure why I am scared to do it. Somehow I feel concerned I might get too slow at the top and end up in a inverted spin... or some other weird thing will happen. Or I will pull too hard and overstress the tail or something.

[Rynoth]

Or I will pull too hard and overstress the tail or something.

Do you happen to have a G-meter? If not there are some apps for phones that can give you a ballpark figure. I never went over 3g's in my loops, and even that felt fairly uncomfortable to my body. I think the plane can handle a lot more G's than I can. Also, G's probably aren't going to stress the tail nearly as much as the main wings. Over-speed on the other hand, might.

If you've never done a loop in any plane though, I'd go back to what Joe said. Find an aerobatic instructor and take some lessons first.

[Arjay]

Mike wrote:

"I tried an Aeroinjector and then an Aerocarb and both had the same issues. I finally bought a Rotec TBI and have not had an issue with it since. I actually feel comfortable flying behind it now. With the aeroinjector/carb I felt like the motor was going to quit at any minute. Best thing I ever did for my plane was throw the aeroinjector/carb in the trash."

Mike:

Some questions: What motor do you have? What model Rotec? How does the Rotec mate to the stock Aerovee intake manifold--is it a direct match, or require modification? Does the Rotec require carb heat? Air filter? What kind of connections are required for fuel input, throttle, mixture, etc.? Where can I get the Rotec?

Thank you for your input

Ron

[gyroron]

Or I will pull too hard and overstress the tail or something.

Do you happen to have a G-meter? If not there are some apps for phones that can give you a ballpark figure. I never went over 3g's in my loops, and even that felt fairly uncomfortable to my body. I think the plane can handle a lot more G's than I can. Also, G's probably aren't going to stress the tail nearly as much as the main wings. Over-speed on the other hand, might.

If you've never done a loop in any plane though, I'd go back to what Joe said. Find an aerobatic instructor and take some lessons first.

The plane has one of those E1 electronic multi function instruments, and one of the settings is a G meter. Not sure how accurate it is.

I have looped before.

Have looped several Phantom ultralight airplanes, Looped the Titan Tornado I used to own many times, and Looped the RV-4 I used to own many times.

Its just one of those things... Its like back in my younger days, there was a bridge going across a cove in the lake we used to boat on. Wanted to jump off that bridge into the lake. Just couldn't get the courage to do it. Finally one day ( after several beers ) a few friends and I swam off the boat to the shore and climbed up to the road and walked out on the bridge... and after a few of them jumped in, I followed. And after that I would jump off that bridge without hesitation.

I was nervous to roll this plane the first time. Took several flights in the plane before I said to myself, Lets just do it already... And I pitched the nose up about 30 degrees, stopped the climb, threw the stick hard over to the right and it rolled right around no problem. Now I have no issues, no fear to roll the plane at all. I just need to say to myself, F it, we are looping this thing today and just go do it. I am sure once I pull off a clean loop or two I will be over my fears and be willing to do them all the time.