Alright, I am almost done with my first gas plane and just wanted to make shure these things are right. First, is it ok for the fuel overflow to be this close to the muffler and is it ok for it to be this short? Second, is there anything wrong with batteries being this close together? no heat problem? third, i know its hard to see but, do the fuel lines look ok and is there any need for wraping the fuel line around the tank? If there is, the one wrapped around the tank is the outlet right? Oh yeah, thanks to everyone who helped me figure out how to assemble my tank, i finally got it together, i feel like an idiot.

I think your setup looks pretty good. About the two battery packs: is one for the RX and one for the ignition? If so, it would be better to separate them a few inches. The fuel overflow looks fine. I can't tell if the plumbing is correct or not from the pictures. Usually the overflow line goes toward the back of the tank, then out the front/bottom of the plane. The reason to use this extra tubing and have it go "backwards, then forwards" is to not lose any fuel when the plane is pointed down.

i am pretty sure that the plumbing is correct, so, do i need the wrap around?

looks great

I don't see anything wrong. I *tried* to follow the tubes, so I'm pretty sure the plumbing is correct.

Have fun!

I'm also curious about the ignition battery and RX battery there. Be sure to carefully range check, you might run into interference troubles with the ignition wiring and the RX and RX battery being so close. Or you might not.

As others have said, the extra length in the vent line is to keep the tank from pouring fuel out in inverted or knife edge flight or dives and such.

Bretd123
Nice job! The only thing I see is both control line tubes kink slightly as they pass into the compartment. If it was me I would move both servo so they line up with the NATURAL lay of the control(Just unhook the link and watch it move!). Again nice job!
Charlie

Out of curiosity, can a gas check valve be used to prevent this?

Maybe, but you'd have to unhook it to put fuel in the tank. I also don't know if the pump in the carb would have trouble pulling against the check valve. I wouldn't think so, but I don't know. I've never seen anyone take that approach though.

There is some minor initial resistance to the vacuum, but once the valve opens this diminishes greatly.

I haven't seen anyone else suggest or try this.

I would run the loop on the vent line, to prevent any fuel coming out on downlines and in teh unlikely event o f a nose over. I wouldn't install a check, while it would prevent fuel from coming out, and wouldnt' be a trouble for the carb pump to pull open, it would be a PITA during refueling ops. Won't let the air out!.

Do try to separate the 2 battery packs. Best practice is for the entire ignition system to be in front of the firewall, separated as much as possible from any radio gear. 6-8" is good, more is better. Of course, moving that ignition pack could introduce cg issues that might require more moving of stuff, but if it reduces the possibility of RFI, it's worth it.

You do pretty nice work! Be sure to range test with and without the engine running. Engine running should not decrease the range. If it does, look to reduce RFI. Many threads on the gas engine forum to help you do this.

Blue skies!

J

Just one thing i noticed

Your using tygon use tie wraps EVERYWARE tygon expans with gas and you dont want them coming off fitttings....

Dont forget to do inside the tank also..


Steven


(I jsut stoll this picture from someone here on rcu to show you what i mean look at all the tygon ends..)

can you use the nylon tie wraps inside the tank without the gass corroding them?

Il let someone else chime in on that one but i do THINK the tie wraps will work, this advice was giving to me when i was thinking about making the jump to gas ...

Steven

Tie wraps will work inside the tank. I would also solder barbs on the tubes for the inside and outside of the tank, then install tie wraps. Also loop the vent line the length of the tank, and no check valves, you want it to get air.

This pic may help some also. My tank is mounted in the canister tunnel (you can see the white tie wraps holding it). The vent line comes up from the tank out on top and around the length, then back down and out the bottom of the plane.

I gotta ask you what are those red tubed you get the servo wires in?

Makes for a nice clean install

Steven

They are wire loom protectors from an auto parts store. The smallest I could fine.

alright, i started the engine and it ran great! I love the sound of that gas engine instead of my .40-.46 planes! Now, do i have to drain out the fuel if I am just going to start the engine again tomarow?

I have no clue where to mount the ignition battery, I have tried a million different ways and none seem to be working. Is there a special place to mount this battery? I looked in the manual and there is no indication of where to mount it.[&:]

alot of people will mount it by the ignition module (under the cowl) if the cg allows it than go for it

You don't need to if you don't mind the smell. Unlike a glow engine, residual gas in the engine will not attract water or corrode parts.

Bretd123,

You get that Diablo finished yet?

Yer' gasser looks like a nice setup. I'm jealous.

Oh you had the diablo? I built the Extra. But anyway, finishing that plane is my next project, i want to go ahead and get this gas plane going first[:@][&:][][:'(]. I'll have the foamie done sooner or later.

Under the cowl!!!!???????? How in the world is there room for it? Do you mean inside of it?