912 ULS fuel return line

[kmach]

Hi,

I am installing a fuel return line from the fuel block to the header tank.

What type of hose have people used in the cockpit ?

What have you used for a restrictor ?
(I dont have the rotax fuel block/bango bolt that has a built in restrictor)

I have an andair check valve on order.

Thanks and pictures welcome

[mr bill]

I used flexible fuel line from the "spider" on top of the engine to the firewall fitting and aluminum tubing from the firewall to the one way valve and the header tank.

[Dorsal]

I used a small distribution block and a restrictor fitting I picked up from Lockwood. The fuel line is the same low permeation hose I used for the rest of the fuel system (the stuff with the blue liner). I ran that hose all the way back to the header tank with a similar check valve at the tank end.
Really clean install Mr. Bill, especially the AP servos!

[kmach]

I have the same 5 port distribution block as in Dorsal's picture. In the picture which line is the return line and has the restrictor in it? I am planning on using a carb brass idle jet for the restrictor at this point.

I don't have the equipment for the aluminum solid line as in MrBills nice setup.
I am thinking a high quality 1/4" rubber hose for the return line . The question is which brand of hose ? What size hose did you guys use ?

[Dorsal]

The vent line is the upper right (the one without the flow sender), I use Goodyear low permeation full injection hose SAE 30R9.

[kitfox2009]

Hi Kevin
I just plumbed mine back to the gascolator with fuel injection hose. I got the restrictor jet from Rotech in Vernon. Can't remember the oriface size. Seems to work well.
Good luck
Don

[AirFox]

I used Baracade hose from NAPA.

[kmach]

Does anyone feel like fire sleeve is required ?
( the firefighter in me coming out).
This question is for firewall rearward , All firewall forward will have fire sleeve.

[Slyfox]

I don't have any on my plane. in fact I found last year my fuel lines started getting pregnant and if I had firesleeve on that line I would have never known they were going bad. yes this is line with the blue insert inside. there is no reason to have any lines firesleeved in my opinion. my rv, different story, much higher temps in the engine area.

now that your asking questions like this. I don't have the return line on my fuel system. now my engine was gotten back in 2009. I removed that whole system and just put straight lines from the pump to the carbs. I thought of some day putting on the return line, but I haven't had any reason to do it. runs great without. if I lived down south more were the temps are a problem maybe. I just don't see where I need it. now talking about taking off my factory firesleeved lines. they did come out and say that those very lines had problems and to replace. I didn't have to do that, I never used that line.:D

[Dorsal]

I do not use fire-sleeve aft of the firewall.

[Slyfox]

I have aluminum lines going from header tank to firewall forward. all other lines firewall back is the blue bing hose.

[kmach]

I am a big fan of aeroquip hose.
For the fuel lines firewall forward I have been using Aeroquip FC332 and will continue firewall forward with it.:)
I think I just answered my own question for the return line aft of the firewall!
It is good to know what others are using .

[Slyfox]

yes, I like that hose also. I prefer that over firesleeve hose. reason, I don't like having a cover over the hose. the hose inside can delaminate and not know it.

[Jerrytex]

I am getting to the point of doing the fuel system. I feel like a I am chasing my tail on this and the internet is not making it any easier. I am planning on running the return line back to the header tank. I can't figure out this restrictor/orfice issue. I see the distribution blocks that people have posted, but I am not seeing how the restrictor thing is working. Has anyone made something or knows what is need to get this done?

[avidflyer]

I filled a fitting with solder, and drilled a hole through it of the size Rotax requires. Can't remember if it's .035 or .040" off hand. Maybe neither. Do what Rotax says I would suggest. My return line going back to the header is soft 3/16" aluminum tubing. And ran alongside the 5/16 aluminum tube for fuel line. JImChuk

[Jerrytex]

Oh, that's a good idea. I bought a set of tiny drill bits, I think .35 mm is in it. Solder would a lot easier to drill. I am assuming you just soldered like the inside of a threaded barbed fitting and then hooked the return up to it?

Seems like someone would come up with an off the shelf easy fix.

[avidflyer]

Yep, that's what I did. Inside a barbed fitting. Drilled 3 holes partway into the sides so the solder would go into them and be for sure to be locked in place. I think I peened the solder before I drilled it as well in case it shrunk at all when it cooled off. The are brass restrictor fittings made to go in an oil line that goes to a sender so if the sender burst, the oil would come out slow also. I have one on my Jabiru oil pressure sender. That was the only one I had though, and they may be to big of an opening. JImChuk

[jrevens]

Jerry,

How old is your engine? They have been coming with the orifice built-in to the top banjo fitting of the block that distributes fuel to both carburetors and that's clamped to the middle of the balance tube for a few years now. You don't need anything bigger than a 1/4" line. I have notes indicating the orifice should be .014" (approximately a #79 drill). If the orifice is too large you may run the risk of insufficient fuel pressure to the carburetors.

[Jerrytex]

Hey John, that's good info that is never even mentioned on the internet that I was able to find. The engine is being delivered today and is brand new. (912 ULS) I was just trying to get everything lined up beforehand since I am running the fuel lines now. I am plumbing in a Facet pump and trying to get everything I need so I don't hit a wall and waste time. I guess I'll wait, and take a look to see if it does have the distribution block. Hopefully so, but if not, I'll be incorporating Jim's remedy.

Thanks