i need to find a way to fit more fuel into my engine housing, is there a good way to make a custom fit fuel tank? the housing tapers down behind the engine so if i could make some like a wedge shape i could get alot more fuel in it. it would be for a twin engine pby catalina
thanks jeff

If it is a confined area, an IV bag might work. I think if you are careful, tanks can be heated and mooshed in to shape.

is brasing your own fuel tank an option???

I'm kicking around a similar problem,right now, but with a Monocoupe build. The short nose, with the model engine set-back,took most of the available space.

It's a scale build,so the instrument panel needs to stay put.One tank could be installed crossways, or two tanks could be mounted "saddle tank" style, one on each side.

In your case do you have room for a large tank,with a smaller tank behind it? The small tank would have the only vent......it's pickup line would go to the vent of the front tank, and as fuel is pulled from the front tank, it would be replaced from the rear one. Same as we did the ducted fan jets from years ago.

My option in the 'coupe is one 12 oz. tank, or 2- 8 oz ones, connected as above.
I'm going to the 'engine' guys with this right now, you might want to see what they have to say.

I have similar tank placement issues in a dirty birdy I'm putting together. What are the most important factors for position of tank? I can get it in the nose but at an angle with the rear of the tank angled up. I assume that is bad for fuel pickup? Does it matter with exhaust pressure? What is the theory? When flying the tank would rarely be level anyways.

I can help with a couple of things...With the rear of the tank higher, you won't access all the fuel when flying level.-there'll still be some in the front of the tank..

The centerline of the tank is usually level with the needle valve entry into the carb, for good all around performance.

Muffler pressure always helps with a smoother fuel draw.
It's better than NO pressure.

I'm wondering if you turn the tank around, with the clunk in the FRONT of the tank ?....on that angle ...a little longer fuel line shouldn't matter, once it's full of fuel.

That is helpful. I think I understand why most with this plane are doing a header tank. The small tank fits in front of the retract well and is nice and level with the centerline in the right place. The larger tank placement further rear doesn't matter as much for good fuel feed?

Originally Posted by Lumpy05

That is helpful. I think I understand why most with this plane are doing a header tank. The small tank fits in front of the retract well and is nice and level with the centerline in the right place. The larger tank placement further rear doesn't matter as much for good fuel feed?

as long as the big one feeds the littler one, they say it'll be fine..

Originally Posted by jeff262

i need to find a way to fit more fuel into my engine housing, is there a good way to make a custom fit fuel tank? the housing tapers down behind the engine so if i could make some like a wedge shape i could get alot more fuel in it. it would be for a twin engine pby catalina
thanks jeff

To come back to the OP question, it is easy to manufacture any shape fuel tank using thin brass sheets about 0.005" thick.

Zor

turbines will use fiberglass tanks. formed to fit the fuselage.

Originally Posted by jeff262

i need to find a way to fit more fuel into my engine housing, is there a good way to make a custom fit fuel tank? the housing tapers down behind the engine so if i could make some like a wedge shape i could get alot more fuel in it. it would be for a twin engine pby catalina
thanks jeff

I might be able to help you out. Here's a thread I started last year. I've made tanks for many different articles UAV's, turbine jets, boats and even a rototiller.

http://www.rcgroups.com/forums/showt...stom+fuel+tank

Ryan