Author Topic: suction fuel tank setup (Read 2958 times)

bill bischoff · « **on:** March 03, 2013, 07:37:19 PM »

This information was originally published in the NCS newsletter in 1995, but since Wayne asked about it, here it is again. Please disregard the phone number as it is not current.

Wayne J. Buran · « **Reply #1 on:** March 04, 2013, 05:22:47 AM »

Thanks Bill.
Wayne

eric david conley · « **Reply #2 on:** March 04, 2013, 09:21:12 AM »

Thanks Bill is right, and I remember when I first read this article in 1995. I had been flying carrier for a little less than 2 years and had lots of questions about everything. This article was one of the light bulb moments for me and I printed the picture and article and hung them on the wall in my building room. I then started building tanks that held just the amount of fuel I needed for each plane and could trouble shoot any engine problems that were caused buy the fuel system. Bill shared so many of his innovative findings in the NCS news letter in almost each issue. I learned to follow his advice early in my carrier flying and it has always paid off. Yes, thank you Bill and keep the information coming. Eric

skyshark58 · « **Reply #3 on:** March 04, 2013, 11:47:21 PM »

Yes I agree with everyone. This is great information and best of all works everytime.

Jim Oliver · « **Reply #4 on:** March 08, 2013, 02:51:46 PM »

Bill,
Thanks for the info.
Please forgive this dumb question: Though this is marked "profile tank" it can be used for built up fuse, right?

Jim

bill bischoff · « **Reply #5 on:** March 08, 2013, 09:59:22 PM »

If you used this particular tank in a built-up model with a side mounted front intake engine, you would need to mount the entire tank outboard of the center line of the airplane, just as if it were a profile. If the tank were centered within the fuselage, it would be too far inboard and its relationship to the carburetor would be incorrect. If the engine was upright or inverted, or rear intake, you could achieve proper fuel system geometry with the tank closer to the center of the airplane. It's all about the ability to get the vent tube 1/4" to 3/8" outboard of the spray bar.

I hope that's not too confusing.

BB

Wayne J. Buran · « **Reply #6 on:** March 09, 2013, 05:25:26 AM »

Bill, would you have an easily found picture of that tank mounted on a profile.
Thanks
Wayne

john e. holliday · « **Reply #7 on:** March 09, 2013, 11:09:12 AM »

Look on page 3 for his post Sneak Preview. Also on some of his other posts is pics of his profile planes. His Crusader shows a plastic tank but I imagine is probably set up similar.

Joe Just · « **Reply #8 on:** March 09, 2013, 03:52:16 PM »

I mostly use Sullivan plastic tanks with the same type of plumbing. Works just great. I only use two tubes, filling through the engine and when I can get away with it the other line runs to the muffler.
Joe

Wayne J. Buran · « **Reply #9 on:** March 09, 2013, 05:37:43 PM »

Saw the tank on the white Zeke. I assume you used something like the Brodak tank mounts for the tank.
Thanks
Wayne

bill bischoff · « **Reply #10 on:** March 09, 2013, 07:37:33 PM »

I solder some 1/2" wide K+S brass strip to the back side of the tank for mounts. Usually the front top and bottom mount are a single continuous piece. I find the flat pieces are easier and less failure prone than bent brackets. On the MO-1, where the tank is recessed into the bottom of the wing, I just glue the tank onto the airplane with silicone.

The Zero tank is longer then the MO-1 tank in the diagram, but only 1" thick instead of 1 1/4". The tubes have the same location relative to the engine, even though the tank enclosure itself is different.

bill bischoff · « **Reply #11 on:** March 09, 2013, 08:10:38 PM »

Here are pictures of four different tank installations. #1 is an MO-1. Note that I have installed a second vent tube in an effort to get the proper air setting vs. ground setting. #2 is a Zero with slightly different tank dimensions. #3 is my Dumas Crusader with the plastic tank. Notice that I ended up using the more inboard fitting for the vent location, again to achieve the proper ground vs. air needle setting. #4 is a Class II MO-1. In order to get the vent tube location far enough outboard, the tank is partially exposed. Fortunately, the rules allow accessories to protrude from the model.

Wayne J. Buran · « **Reply #12 on:** March 10, 2013, 07:01:39 AM »

Bill, thanks for the input. I was trying to compare my setup with yours and although I use stock wide wedge tanks into the wing when required I do see that the P/U is within that 1/4 to 3/8 range. What is the rough volume of the tank that is illustrated in this thread.
Thanks
Wayne

bill bischoff · « **Reply #13 on:** March 10, 2013, 10:19:24 AM »

The tank shown is 5.2 ounces. You commented about the pickup location of your tank. The most important thing is the placement of the vent, rather than the pickup. The short version is that the VENT needs to be about 1/4" to 3/8" outboard of the spraybar, preferably at the front of the tank.

BillLee · « **Reply #14 on:** March 10, 2013, 11:28:30 AM »

Bill, with the vent at the front of the tank, does that mean the tank becomes normally vented when in hang mode?

skyshark58 · « **Reply #15 on:** March 10, 2013, 12:53:28 PM »

The vent on the F8 and Zero are up against the fuselage,clamped down.. What's up with that?

bill bischoff · « **Reply #16 on:** March 10, 2013, 01:13:08 PM »

The critical thing is where the air actually enters the fuel inside the tank. I put the exposed end of the vent above the fuel tank and as far inboard as possible, just to keep fuel from siphoning out in flight. It is also convenient for filling the tank. What is not evident in the photo of the Zero tank is the fact that the vent tube doesn't just stop where it enters the tank. It goes to the same location as shown on the MO-1 tank.

In answer to Bil Lee, yes, you lose the uniflow property in slow flight. This is addressed in the text above.

Wayne J. Buran · « **Reply #17 on:** March 10, 2013, 02:11:18 PM »

Bill, thanks for the info.
Wayne

skyshark58 · « **Reply #18 on:** March 10, 2013, 02:40:26 PM »

So the vent on the Zero must do a 90 inside the tank and almost touch the fuel supply inside.

bill bischoff · « **Reply #19 on:** March 10, 2013, 04:39:51 PM »

Actually it goes to the bottom of the tank, but it is about as far outboard as where the fuel pickup line emerges.

Author Topic: suction fuel tank setup (Read 2958 times)

Joe Just