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Old Jan 27, 2013, 10:14 AM
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DarZeelon's Avatar
Israel, Ramat HaSharon
Joined Nov 2003
1,155 Posts
Quote:
Originally Posted by S3NFO View Post
Your theory is great Dar, but my practical application from dozens of glow DF jets beats your theory every time. As long as the fuel line from the tanks to the T's is the same length, I've never, ever had a problem with one tank running dry while the other still had fuel.
I'd bet there are several thousand old school DF guys out there who've run 2 saddle tanks in parallel with no problems.
S3NFO,


So, are you saying your way is trying everything on your own???

"So, that other guy died from jumping off the roof... I'm sure I will survive it. I'm jumping off now!"

What theory predicts can happen, eventually will happen.
I don't know if the fuel-tanks in your DF jets are visible from the outside, but can you still tell me if you ever observed, immediately after landing, a noticeable difference in fuel-level between them?

Immediately, because the physical 'law of connected vessels' will equalize the levels within a few seconds.

The only possibility for one tank (or one side of the saddle) to deplete itself earlier, is if gravity perceives its bottom as being higher than that of its counterpart...

...Which can happen as a result of various issues that I mentioned in my previous posts.
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Old Jan 27, 2013, 10:16 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
1,263 Posts
Quote:
Originally Posted by epoxyearl View Post
The solution,in my case is NOT a single tank....I want the extra fuel that only two tanks can provide..
I watched a video recently of a pattern plane with a clear tank mounted outside the airplane.....at times the fuel was suspended at the top of the tank in level upright flight. There was fuel movement the entire flight. At time the pickup was uncovered and the engine continued to run,from the fuel in the lines. It was immediately replaced by muffler pressure when the clunk became resubmerged.

You did understand that I'm using muffler pressure to the single vent, and it's a 4 stroke, with excellent fuel draw, correct?
Engine connected to tank "A", vent line of tank "A" connected to tank "B" clunk line, tank "B" vent connected to muffler pressure.

Mount the tanks beside each other on the same level.
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Last edited by SrTelemaster; Jan 27, 2013 at 10:24 AM.
Old Jan 27, 2013, 11:49 AM
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United States, MD, Elkton
Joined Oct 2011
8,603 Posts
Throw out the bad advise, implement the good, We laid down the drawings for the recessed engine mount and twin fuel tanks...It's a GO!
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Old Jan 28, 2013, 01:57 PM
Registered User
USA, CA, Santee
Joined Jul 2002
304 Posts
Quote:
Originally Posted by DarZeelon View Post
S3NFO,


So, are you saying your way is trying everything on your own???

"So, that other guy died from jumping off the roof... I'm sure I will survive it. I'm jumping off now!"

What theory predicts can happen, eventually will happen.
I don't know if the fuel-tanks in your DF jets are visible from the outside, but can you still tell me if you ever observed, immediately after landing, a noticeable difference in fuel-level between them?

Immediately, because the physical 'law of connected vessels' will equalize the levels within a few seconds.

The only possibility for one tank (or one side of the saddle) to deplete itself earlier, is if gravity perceives its bottom as being higher than that of its counterpart...

...Which can happen as a result of various issues that I mentioned in my previous posts.

Noooo, I'm saying that 1,000 glow DF guys before me used parallel tanks and I benefited from their experience, and that 10 years of practical application from never having a dead stick from fuel starvation "should" be worth something. Serial tanks are definately easier, and all I use on turbine, but parallel tanks works fine.
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Old Jan 28, 2013, 02:16 PM
dusty bible = dirty life
Majortomski's Avatar
Oklahoma City OK USA Where fakts still exist even if they are ignored
Joined Aug 2000
2,772 Posts
May I suggest one other possible solution?

Plumb the tanks in series.

The line from the clunk in tank one goes to the vent line in tank two.
The line from the clunk in tank two goes to the engine.
The pressure line off the muffler goes to the vent line on tank one.

As the engine draws fuel from tank two the exhaust pressure pushes the fuel in tank one to tank two. Tank one goes empty and the pressure just passes through to the top of the fuel surface in tank two until depleated.

No problems with sucking air from either tank.

MTC YMMV
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Old Jan 28, 2013, 02:22 PM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
1,263 Posts
Quote:
Originally Posted by Majortomski View Post
May I suggest one other possible solution?

Plumb the tanks in series.

The line from the clunk in tank one goes to the vent line in tank two.
The line from the clunk in tank two goes to the engine.
The pressure line off the muffler goes to the vent line on tank one.

As the engine draws fuel from tank two the exhaust pressure pushes the fuel in tank one to tank two. Tank one goes empty and the pressure just passes through to the top of the fuel surface in tank two until depleated.

No problems with sucking air from either tank.

MTC YMMV
I believ the OP has already determined that is the way he is going to go.
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