Fuel tank modifications

[DWheat9003]

Has anyone heard of fuel tank modification to stop or at least alleviate the problem of fuel aeration? My son had the article in one of his mags but I can't find the article now, I don't know the details as to the modification. Any help on where I can get the info and the diagrams to do this would be appreciated.


D. C. Wheat

[StevePond]

There's not much you can do to prevent vibration, which is the primary cause of foaming of the fuel. If you're getting a lot of air bubbles in the fuel, that could be a different issue not related to this. Is there a problem with the engine that you think is caused by foaming fuel?

[DWheat9003]

No there’s not, but the article I mentioned had the fix for a supposed problem caused by high speed foaming of the fuel. This foaming is supposedly caused by the pumping action of the engine, which is of course is pressurizing the tank. Those pressurizing pulses are aerating the fuel, as it was mentioned.
I have a this high speed starvation problem I believe because I have been able to get the car to work perfectly except for the very last part of the throttle. The only thing I remember about the fix was the relocating of the pressurizing line and a replacement metal fitting and using a screw and special sealers to seal the screw for the old port and the new fitting.

D. C. Wheat

[kedar]

would isolating the tank from the chassis w/ o-rings help?

[Paul_D]

Check here, about 1/2 way down the page - Fuel Tank Isolation...

http://www.rcnitro.com/information/nitro_tips.asp

Not sure if this is what your talking about, but it looks like it may do the job.

[DWheat9003]

I appreciate it Paul D., I will try that fix I guess since it could only help I would think. But my original question was based on a fix that was purported to be the fix for the foaming, but I will try the suggestion from the link you sent.

Thanks,

D. C. Wheat

[craigb]

I have your solution for you! I saw a fix for this problem of "fuel areation" for the Losi NXT. I have since performed this mod and it has been working trouble free on my truck. The outlet on the fuel tank which is connected to the pressure fitting on the muffler/tuned pipe should first be sealed off. I threaded a small screw into the hole and coated it with epoxy. Then obtain any pressure tap (like one from Du-bro) and install it preferrably in the lid to the fuel tank. First try drilling holes of increasing diameter in a scrap piece of plastic, tap it if you have a tap or practice threading the pressure tap into the plastic to "force" some threads into it. Then drill the appropriate size hole in the fuel tank lid and thread in the pressure tap. Apply some silicone sealant around the tap to insure no air leaks. Attach thje pressure line between the new pessure tap and your muffler/tuned pipe and you should be good to go. Hope this works for you.
Peace

[DWheat9003]

You hit the nail on the head, that sounds exactly like the fix I read about but I didn't remember the details like the fitting in the lid ect. I appreciate the response and this will be of much help I am positive.

Thanks,
D.C. Wheat

[Interstate]

Something else that may help, is using longer fuel lines from the pipe to the tank; it helps smooth out the pulses.

[DWheat9003]

Thanks, I will do that too.

D. C. Wheat

[kedar]

read this article, its really good: The Cold War On Tuned Pipes (http://www.angelfire.com/extreme3/rccarbroken/pipes.html)

also check out the section on fuel and pressure lines.

[InspGadgt]

well i ran into a problem with airbubbles in the fuel line once when i made the pressure line too long to compensate for a smaller fuel tank on my TGR. With the airbubbles the engine would lean out and die after about 4 minutes. Going back to the stock length of pressure tubing solved this problem.