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  #11  
Old 04-07-2020, 05:21 PM
Freemasm Freemasm is offline
 
Join Date: Nov 2017
Location: Orlando
Posts: 135
Default Testing, testing

Don't have anything to add but was curious if a shared google photo movie would work here. Here goes nothing (below). Obviously documenting my tank build.

https://photos.app.goo.gl/5P366KfCxHNs8KeMA

Last edited by Freemasm : 04-23-2020 at 05:23 AM. Reason: link update
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  #12  
Old 04-07-2020, 05:23 PM
Freemasm Freemasm is offline
 
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Location: Orlando
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Quote:
Originally Posted by emsvitil View Post
Only if the flop tube and normal pickup are T'd together

With a L Aux R fuel valve you wouldn't have that problem
Makes no sense. You're proposing a third pick-up in two tanks.
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  #13  
Old 04-07-2020, 05:31 PM
Freemasm Freemasm is offline
 
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Location: Orlando
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Quote:
Originally Posted by 007 View Post
I'm curious about the statement reference usable fuel in the aerobic tank in an RV4. My tanks are built to plans and all 16 gallons are usable.

Joel
Complete brain fart on my behalf. I had senders on my mind from the OPs original questions. Was taking a break from this "work at home" ****. Sorry. My bad.

BTW. Where in VanAire, CO?
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  #14  
Old 04-09-2020, 12:56 PM
007 007 is offline
 
Join Date: Mar 2010
Location: VanAire, Co
Posts: 25
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Ok. Understand.
Both fuel QUANTITY indicators will show zero when tanks are zero, but aerobatic tank will not show more than 13 gallons, when full, on my build.
VanAire is 15 miles north of DIA.
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  #15  
Old 04-13-2020, 07:25 PM
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NorthernRV4 NorthernRV4 is offline
 
Join Date: Mar 2013
Location: Prince Edward Island, Canada
Posts: 137
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spent way more time than I expected fiddling with the trap door but I'm pleased with how it turned out. I'm left wondering about the hole in the center of the rib. Should I cover it over or put a door on it too? I don't quite understand why the plans call out for this hole if the hole in the bottom rear corner of the ribs allows for fuel transfer.

Starboard fuel tank rib by James Soutar, on Flickr

Starboard fuel tank rib by James Soutar, on Flickr
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  #16  
Old 04-14-2020, 10:53 AM
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smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,877
Default I needa...

Quote:
Originally Posted by NorthernRV4 View Post
Good day fellow RV'ers

This winter I've been building the starboard wing and I'm at the point of putting the finishing touches on the tank. Firstly, this tank is getting a flop tube and the standard Van's resistive fuel senders. I'm looking for some tips & advice specifically on mounting the sender in the second rib bay and the anti-hang up guide strap. Van's plans are pretty simplistic and don't show at all any dimensions for mounting the sender.

1. For the sender, do you mount it in a cover plate similar to the end rib to allow for greater access and ease the inserting of the sender/float arm? Or is a simple hole for the sender sufficient?

2. At what vertical position would the sender be mounted in the rear baffle? I would think roughly the same position as mounting it in the end rib would put it.

3. Do you bend the rod to the same dimensions as if it was mounted in the rib? I'd rather not have the tank all sealed up only to find the fuel gauge is way off. I expect some inaccuracy but I'd like it to be as close as possible.

and lastly, in regards to the strap. Did you just fabricate a guide that looks like the diagram provided in the plans? Any specifics here to consider?

Thanks in advance, keep calm and build on!

Starboard fuel tank by James Soutar, on Flickr

Starboard fuel tank by James Soutar, on Flickr
Hey Jim,
I built my Four BE-FORE the internet, VAF, heavy weldments, long gear and yes, flop tubes. Over the past 2000 hours of ownership by two(major league ADD) former Fighter pilots, the need for sustained inverted never materialized.
Positive G Acro, 1V1's and lots of yanking a banking never (OK maybe once ) exceeded the fuel cavitation abilities of a Carb and mechanical pump.
So, don't burn too many brain cells on inverted fuel/oil or associated systems if you don't have to...

Your bigger concern over time will be leaks, trust me.

V/R
Smokey
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  #17  
Old 04-14-2020, 04:23 PM
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Z-EDD Z-EDD is offline
 
Join Date: Oct 2013
Location: Harare, Zimbabwe
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Quote:
Originally Posted by NorthernRV4 View Post
What do you mean about the o-ring on the brass end? My prefab'd flop tube from Vans has one installed already. I assume that's simply to act as a cushion.
I believe there is an SB/letter/some sort of recommendation to use some proseal to glue that O-ring in place, otherwise it has been known to go astray.
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  #18  
Old 04-15-2020, 06:23 AM
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NorthernRV4 NorthernRV4 is offline
 
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Location: Prince Edward Island, Canada
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Thanks Smokey, I'm not sure how much I'll need the inverted option. Just nice to have for the future potential and hey, there is a certain cache' to be able to say "because I was inverted" ;-) Seriously I wanted the experience of building one tank this way as much as anything.

Last night I bent up the float arm as per the Van's drawing and located it in the rear baffle. I put it in the inboard rib so I could check the position of the low fuel condition and found the float was 1/4" off the bottom tank skin so I used this as the baseline for the vertical position. For my setup this proved to be 4" from the bottom of the rear baffle lower flange. I located it as close to the 2nd rib as possible while keeping the float clear of the rib so it would be as accurate at the low fuel position as possible. I fabricated a reinforcing ring to be mounted in the rear baffle. While the plans don't show it, I wanted to keep that area as stiff as possible for mounting the sender to prevent leaks.

For the trap door(s) in rib #2 I think I"ll rivet a cover plate over the center fuel transfer hole. I think the lower aft hole is plenty to transfer fuel and in this case, I can't see the benefit of the complexity of a second trap door.

RH fuel sender by James Soutar, on Flickr
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  #19  
Old 04-16-2020, 12:49 PM
71459 71459 is offline
 
Join Date: Jun 2019
Location: Seattle, WA
Posts: 49
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Reality check.. you absolutely will install the (complicated, heavy, and expensive) inverted fuel and oil systems on the engine, right?

My experience is the same as Smokey's - I installed this flop tube thinking I would use it some day, but after over 1000 hours that need has never materialized. I ended up taking it out and putting in a standard aluminum pickup tube.
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  #20  
Old 04-18-2020, 05:20 AM
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BruceMe BruceMe is offline
 
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Location: Shawnee, Kansas
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Quote:
Originally Posted by 007 View Post
I'm curious about the statement reference usable fuel in the aerobic tank in an RV4. My tanks are built to plans and all 16 gallons are usable.

Joel
Same... 100% usable both flop and tube pickup.
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