I was working on my venture last night again finally...and i just dont like how the fuel tank sits in it..i know its standard, but i have huge hands and managing to get the tank in and foem in and every thing else (fuel tubing through the hole) is just a pain...and im get frustrated with it quickly...

Im putting the servos for the tail in the tail...so the only servo up front would be the throttle...and i could put the battery and receiver under the tray for the tank thats there now...

Im putting a saito 91 in there which everyone says will make it nose heavy..and the servos in the tail will help a little but you still need to add some weight back there to get it even...i figure if i can put the tank just forward of the cg above the wing, that would help both the CG and the small space problem, plus it would mean that the CG would change less in flight.

My only concern was the added length of fuel line (about 6-8 more inches) and whether or not that would affect the fuel pressure enough to be a problem.

I am going to add smoke as well later...and could put it maybe where the fuel is supposed to go..but i really dont know...

I guess the big thing is the length of line, so verdict?

Unless you have a pumped/regulated engine I do not recommend placing the tank as far back as you suggest. You will have troubles adjusting the engine to run smoothly both when climbing and diving. Mount your tank in the position suggested in the plans

As for long fuel line lengths, the friction between the fuel and the inner wall of the fuel tubing increases linearly with length and decrease with the internal diameter to the fourth power, i.e. decresing the i.d. to half the original value will cause the friction losses to increase 16 times (2x2x2x2). Thus it is much more important to use large i.d. fuel tubing rather than keeping its length short. The distance between the tank and the engine should be kept as short as possible because of the pressure head differences.

/Red B.

rjm, i cannot help you as im too new but i can relate to the huge hands thing,frustrates the heck out of me,stay with bigger planes is the only solution i can think of lol

Put the tank in according to the plans. This isn't something you will need to mess with all the time. Suck it up and put it where it belongs.

Yes, long fuel line runs are not good. Most engines don't have enough vacuum draw to pull the fuel very far, even if muffler pressure is used.

Long not good, short, good!

true

One way I've solved this issue in the past is to run a wire of sorts through the firewall, and into the fuse. I've used wire coat hangers many times for this. Then, slide the fuel tubing over the coat hangers, and pull the coat hangers out as you push the tank in. The tubing will come right out the hole with the coat hanger, and the tank should slide right into place for you. Just remember to run two wires up into the fuse at the same time, so that you can pull both fuel tubes through at the same time. You might have to get something like kitchen tongs or the sort to help if the tank needs to go up into the front of the fuse farther than your hands will push it. If necessary, consider cutting a tank hatch in the bottom of the fuse for access to the tank compartment.

Yes, long not good, short better, but I sure get a lot of emails telling me the opposite. In general, unless you use a pumped or crank pressurized system, you should keep the tank close to the engine.

However, if you select distant location, you can resolve most of the fuel delivery problem with a header tank. This "trick" is used in some pattern setups where having the fuel tank on CG is ideal. It is also used on many helis to prevent air in the lines during 3D, etc. Just get a small tank, say 1-2oz, and place it up by the firewall. It is plumbed to be between the primary tank and engine. You fill thru this tank back to the primary. Likewise, the engine draws thru this tank, with the primary behind. The idea is that the header tank will always stay full as long as the primary hasn't run dry, and the lines from this tank to engine are short. System should pressurize properly. This will slightly shift your CG forward, depending upon the size of the header tank, because the header tank will always be full of fuel (think of it as dead weight.) So if that is a concern, use a small tank and compensate accordingly. Cheers.

i ALWAYS keep my fuel line as short as possible

There are a number of tricks for easing a fuel tank into a cramped location.

Rubberband the lines together at the loose ends and use a "fish" line. Nyrod works good to stick through the firewall and plug into one of the fuel lines. You then pull them through together. Other stuff works as a fish line etc etc

But your idea about the tank at the CG sounds good also. Putting it at the CG is going to make the extra small tank that's been mentioned a great idea. Or using a pump is a good idea. And muffler pressure may work to support that two-tank setup, but maybe won't.

You've not mentioned the model.

Actually he did in orig post. It's a Venture.

Yeah, a BTE Venture 60...

But i can see why you missed it, its not one of the "popular" ones that sticks out as a model when you skim over the name...

chuckle.... Yeah, when I read about his venture, I assumed that he was building his own design and it wasn't a run of the mill layout.... so I've just tried to find something on the internet that'd show it......... and was that a venture

Not hard at all:

http://www.rcuniverse.com/forum/fb.asp?m=4067105
or
www.BTEmodels.com