The standard flop tube in the wing tank with a barn door in the baffle works just fine. I have no problem with inverted flight even down to three gallons in the tank.
The standard flop tube in the wing tank with a barn door in the baffle works just fine. I have no problem with inverted flight even down to three gallons in the tank.
I am planning to convert my O-360 to FI with an airflow performance system. In the installation manual, there are severe warnings about air in the fuel.
So with a floppy tube in the wing tank, there will sometimes be some air in the fuel. Just consider flying 0G for some seconds, with only 5 liters in the tank.
So, what HAPPENS when some air is sucked into the fuel line? Some rough running or does the engine shut down completely?
Same when running empty in one wing - if you switch over to the other tank when you notice you are running dry, will the engine recover like it does with a carburetor, or will something worse happen?
Not being able to run a tank dry would substantially increase the minimum volume you can fly on.
I am changing to FI for acro flying, so please advice if it will work fine, else I will save my money.
Ron - you are writing "barn door in baffle". Sry I donot understand that, what does it mean?
//HR
Anyone that can help me with my questions?
Hi Hans,
The "barn door" is just a small hinged door in the inboard tank rib that opens to allow fuel to flow towards the fuel pickup and closes when fuel tries to flow towards the wing tip.
Thanks Ron.
Sound like it is possible to do w/o an acro tank.
The barn door sounds smart, making sure fuel stays close to the pickup
I haven't yet removed the tank (and I have not built the plane) so I do not know how it looks like, but I guess the barn door would require to cut the tank open, mount the barn door and then weld it together again.
Can you do four point or slow rolls both ways w/o problem?
No need for an acro tank.
With a tank at least 1/3 full
Hmmm I fly acro with just a couple of gallons to keep weight down.
I typically start a practice session with 6 or 7 gallons in each tank but have started with more than that with little noticeable difference. I'm sure I have run a tank down to 3 gallons or so many times with no issues.
Thx Ron.
But that's with the "barn door".
I guess I will just have to try.
A typical Sportsman sequence doesn't have any sustained knife edge flight. I don't think you will have any issues even without the door.
Thanks Ron.
Sound like it is possible to do w/o an acro tank.
The barn door sounds smart, making sure fuel stays close to the pickup
I haven't yet removed the tank (and I have not built the plane) so I do not know how it looks like, but I guess the barn door would require to cut the tank open, mount the barn door and then weld it together again.
Can you do four point or slow rolls both ways w/o problem?
These tanks aren’t welded.. they are riveted and sealed with a sealant. You shouldn’t weld on 2024 aluminum..
Thx for advise. As you understand, I have not built my RV-8.
I guess then the tank roof and floor is the skin of the wing? Might make it more difficult. Can I access the tank to even mount the floppy w/o removing the wing?
Found this website showing a design of a trapdoor to keep fuel close to the floppy. http://jtsrv8project.blogspot.com/2007/09/inverted-flight-fuel-tank-mod-pt2.html
ronschreck;1488507 I would leave this project alone until after Christmas as you don't want to spoil the holiday with profanity and busted knuckles. Merry Christmas.[/QUOTE said:Thx Ron for a very detailed description!
I will wait with the tank until I have the FI installed.
However, here in Sweden we have ****ty flying weather october - jan, so I dont even have it insured, so it is a very good period for some work.
The pic of the trap door, is it about your barn door design?
The pic of the trap door, is it about your barn door design?
Yes. You should put a tab on the door to make sure it can't open more than 90-degrees so it closes easily when fuel tries to flow back through the opening.