Flop tube retrofit

[pnassar]

I purchased a beautiful RV-7 two months ago. Equipped with IO360 A1B6, and yes, a Christen inverted oil system, but no flop tube. Iv'e read several posts on flop tube installation in quick builds but have not found much on fully completed retrofits. If anyone has completed this or has any thoughts I would appreciate the input.

After reviewing the plans I am thinking at minimum I need to remove the fuel tank. The other concern is the need/ability to place a one way door on the lateral baffle to trap the fuel in the inboard bay where the flop is.

Thanks much !

[LifeofReiley]

Welcome to VAF... N267RV is a nice plane. PainterJohn painted that RV.

[wirejock]

Yes. The tank would have to come off. You can order the flop tube kit from Vans and it should come with a blank access panel. The other issue will be the senders. If your tanks have standard senders, they get relocated to the rear baffle or you could install an aftermarket capacitive sending unit. The only difficult install would be the trap doors but if you're cutting a hole in the baffle to move the sender, it may give you access to install the trap door.

[pnassar]

Thanks for the quick reply !
A few more questions...
Any preference as to left or right side to install?
Will I need to fabricate the trap door or are these available ?
Will exterior of the tank need to be cut at all. Hoping to get everything done through the root access panel...or posterior of tank.

Thanks

Pete

[wirejock]

Originally Posted by pnassar

Thanks for the quick reply !
A few more questions...
Any preference as to left or right side to install?
Will I need to fabricate the trap door or are these available ?
Will exterior of the tank need to be cut at all. Hoping to get everything done through the root access panel...or posterior of tank.

Thanks

Pete

Side is your preference but others may have a more experienced opinion. I put mine on the left but I'm still building.

You need to fabricate the trap door. I think the plans call for .025" sheet. I put a shim under the hinge where it rivets to the rib so it would flap down even with the rib. On mine the hinge is on the inboard side of the trap door.

No cutting of the skin is needed. The flop tube fitting is located in the forward most corner of the inboard rib. There is a 1/8" thick tank mount there. It's tricky to locate the fitting and you will have to drill the hole through it. The baffle may need a hole depending on your choice of sender and to install the trap door. The hole for the trap door is in the second rib all the way aft at the bottom. I think Vans sells the baffle hole cover.

One more thing. You need to fabricate two anti hang brackets from 1/2" X .025" stock. One goes from the rear stiffener in the inboard bay to the second rib. The other goes across the access hole. They keep the flop tube from hanging up on interior parts.
Look at someone's build blog photos to see how it all looks. My Tank page has several photos. Web line is in the signature below.

[pnassar]

Thanks much... let you know how it turns out !

Pete