Author Topic: Tanks (Read 738 times)

Kelly Wilson · « **on:** August 11, 2009, 11:54:22 AM »

I was recently given/gifted several very cool older carrier planes. I am presently in the process of refurbing them. There are several class I planes and a class II. I am cleaning them up and refurbing the engines, but I do not believe they can be put back in flying condition without replacing the tanks and control systems. To replace the control systems would basically require destroying the planes and I am not going to do that. I will try to put them in good shape and hang them up for conversation pieces.

However there is a MO-1 profile that will be flyable. The tank system will have to be replaced. It has a rather large inboard metal tank that feeds a small header tank on the outboard side. The main tank is setup uniflo with a feed and balance line thru the fuse to the header tank. My question is.... is all of that really necessary and is that still the tank setup of choice today?? It looks like a lot of extra fuel and complicated plumbing.

The original engine is a K&B 5.8 RE. If I can gather all the parts necessary I will use it, if not I will replace it with a newer OS engine.

I would appreciate any comments and advice.

Kelly Wilson

Peter Mazur · « **Reply #1 on:** August 11, 2009, 01:00:24 PM »

This is a "chicken hopper" tank setup and it is the best you can do for a Profile fuel system. The big tank is not uniflowed, it is to be completely sealed (with no leaks at all!) and connected by those two tubes, the feed and return lines, to the little tank. The little tank is uniflowed, with the inner location of the vent tube carefully chosen to be the virtual fuel level as far as the fuel feed to the engine is concerned. Assuming this worked once in the plane's first incarnation, you should be able to make it work again. The advantage of this setup is that the fuel pressure to the engine does not change as the fuel is consumed, right up to the point where the big tank goes empty. So you can have a completely consistent run through the whole flight.
The K&B 5.8, if it is in decent shape, can be quite powerful and should have more power than most of the modern non-racing engines you are likely to buy. The idle adjustments, on the other hand, might not be quite so easy on a sport engine. It is worth a try, at least on a test stand.
Pete

Mike Anderson · « **Reply #2 on:** August 11, 2009, 01:03:38 PM »

I have an MO-1 Profile with a 5.8 - I use a 6 oz. clunk tank, mounted directly behind the engine that actually has to mount at an angle to go under the wing -

I can usually manage 30-40 second laps in good air and after a 7 laps high, 7 laps low and a couple of 'setup' laps to a landing I usually have well over an ounce of fuel left in the tank. This is with 65% Nitro fuel.

Also, if you use a clunk tank with a Rear Exhaust engine, you will probably need some type of simple exhaust deflector to keep the hot gas off the tank bung and neck.

I would try a similar setup, in your case, and if it proves to be not enough fuel, you can also go back to what it has on it.

dale gleason · « **Reply #3 on:** August 18, 2009, 07:28:46 AM »

The Bischoff Profile MO1 and his Profile Sniper use a simple rectangular tank with the fuel feed line going from the outside bottom rear of the tank, an overflow that is capped in flight and a vent facing into the slip stream. This vent is located about a quarter inch outside the needle valve. A plywood plate on the front of the tank insulates it from the rear exhaust if that type motor is used. The tank in both type planes is inletted into the leading edge of the wing. Perhaps this might be a viable option, dale g.

Balsa Butcher · « **Reply #4 on:** August 18, 2009, 09:15:02 AM »

If it were my plane I would just mount a 3.25 GRW chicken hopper tank (sold by RSM) behind the engine. Unless you are serious about high nitro fuel, racing engines, and extended low speed via prop hanging that will be enough fuel for sport or competition flying. The rear exhaust configuration is an issue so I would replace the K&B with a modern engine such as the OS (.32?) you mentioned. Much more user friendly and plenty of power.

Author Topic: Tanks (Read 738 times)

Kelly Wilson

Tanks

Peter Mazur

Re: Tanks

Mike Anderson

Re: Tanks

dale gleason

Re: Tanks

Balsa Butcher

Re: Tanks