[pa38112]

I have seen tones of photos of the red cube mounted in the engine bay and on the fire wall. I am planning on mounting mine in the tunnel after the electric fuel pump (RV6A). Could somone post photos of this mounting configuration ? I'm looking for ideas on the bracket.
Thanks !

 

[pa38112]

I know you are out there, at least acording to the threads - maybe not, and that is why I can't find photos.

 

[Gary 40274]

Troubles with that location

Lots of folks have troubles with that location and have moved it to the engine compartment. I would recomend against having it thee and put it between the servo and the spider. Let me know if you want more info about the problems.

Gary Specketer
Tech Counselor/Flight advisor

 

[jdeas]

RV7 install

I wanted the unit in the tunnel as I felt it may indicate FWF leaks where other locations may not. Here are some build pics. I don't have any pics of the extended doghouse or finished install but if your interested I can send you a photo and the layout sheet to bend up the DH extension.

 

[pa38112]

"Lots of folks have troubles with that location and have moved it to the engine compartment. I would recomend against having it thee and put it between the servo and the spider. Let me know if you want more info about the problems."

I have read many thread on the subject, and concluded from them that the issue is more related to the transducer that EI used before the red cube. With the red cub the only problem I am aware of is that the reading is affected by the electric fuel pump. This does not concern me, because I do not plan on using it to measure total fuel consumption. I am more interested in my fuel flow during leaning/cruse when the electric pump will be off.
If you have additional information I would be more than interested in it.
Thanks. - Also, I may have used the wron term when I said "in the tunnel". My fuel line run up the left side of the fuselage about 1" off of the floor. This is where I intend to install the red cube - on the left wall, about at my knee, 1" or so off of the floor.

 

[jdeas]

Not applicable

I thought the 6 and 7 shared the same basic fuel line routing. Sorry about that.

 

[RV10Rob]

With the red cub the only problem I am aware of is that the reading is affected by the electric fuel pump. This does not concern me, because I do not plan on using it to measure total fuel consumption. I am more interested in my fuel flow during leaning/cruse when the electric pump will be off.

Even if you do plan to use it to measure total fuel consumption, it isn't a problem. The error is small enough (at least on the RV-10) and the electric pump runs so infrequently that the net effect on the fuel consumption data is inconsequential.

-Rob

 

[GLPalinkas]

Lots of folks have troubles with that location and have moved it to the engine compartment. I would recomend against having it thee and put it between the servo and the spider. Let me know if you want more info about the problems.

Gary Specketer
Tech Counselor/Flight advisor

Gary, can you elaborate on what you have seen as trouble with that location (in the aft of the FW cockpit fuel line route). I have seen red cubes installed that way and even one of the VAF guru's has his in that location in his -6. ( DAR Mel )

I cannot find many negatives on VAF with the exception that the accuracy of the reading may be degraded slightly. I know EI suggests FWF but then again the fuel fire risk also has to be much higher.

Thanks for any info you can supply as my red cube is on my ToDo List (freshly replaced by EI because I had an uninstalled older model .... Thanks guys)

 

[C-FAH Q]

Location

I mounted mine 3" aft of the firewall, in the tunnel area. I did make a raised tunnel from the fuel selector valve to the firewall, so the cube is hidden in this area. I have had no issues from mounting it here.

 

[pa38112]

Do you have a photo of how you did this ?

 

[gtmule]

I think I like the idea of mounting it Aft of the firewall more and more. Two less connections getting fatigued, some chance of spotting a fuel leak (at least a major one), one less hose. 4 less FWF connections to leak, less clutter, etc.

I will say IF the unit is affected by the electric pump (I'm carbed, with the pump on the firewall, so I don't think it would be) you'll want to calibrate it whenever way indicates LOWER fuel flow (pump on or off), so you're always conservative with quantity remaining.

 

[jdeas]

Flow around bends

The reason I placed my cube away from the FW connection was due to the sweep of the tubing. I read somewhere in the installation to be careful of turns on the fuel line near the red cube. Placing it just foward of the existing fuel pump doghouse gave the least amount of curves near the cube.

 

[vickruis]

I also mounted mine in the tunnel.

Usually, when I opened the canopy, I would smell the leather seats. After 6 months of flying, that smell was replaced by a very faint smell of avgas.
I finally spotted a blue stain under the red cube, and it appeared that I had forgotten to use fuelube on the fitting... Oops, but easy to fix.

Would I put the red cube in the tunnel again? Yes, the leak I had would probably stay unnoticed for months if the red cube would be forward of the firewall. I does create an extra point of failure inside the cabin, but any failure would be noticed much earlier.

 

[pa38112]

Here is what I am thinking of doing - connecting the red cube to my electric fuel pump with a nipple. My other option is to put it closer to the rudder, but I don't want it to be in the way of my feet. Any thoughts or suggestions ?

[/IMG]
Option one

Option two

 

[Taildrgr]

When mounting the red cube in the RV-7A tunnel, is it necessary to make a physical connection of the cube to the fuselage floor, or will the 3/8 fuel tubing provide a stiff enough mount? I have 1/8" foam insulation on the floor and the cube sits on top of the thin foam. It seems pretty rigid this way, but I am curious about the experts opinions.

 

[Walt]

I also mounted mine in the tunnel.

Usually, when I opened the canopy, I would smell the leather seats. After 6 months of flying, that smell was replaced by a very faint smell of avgas.
I finally spotted a blue stain under the red cube, and it appeared that I had forgotten to use fuelube on the fitting... Oops, but easy to fix.

Don't use fuel lube or you will be doing the job again soon
There are others but this one works pretty good.

 

[Geeman]

Downstream or upstream of the electric pump?

I am about to start this installation in my RV-6. My facet electric is mounted on the firewall. I thought about installing the fuel meter in the fuselage upstream of the electric. Between the selector and the electric.

Will this work?

 

[WenEng]

This look OK for red cube mounting in tunnel?

I guess it works about anywhere according to all who have mounted it everywhere... And, as Brian often mentions in Red Cube threads, the tubing does not need to be straight in or out. Thats a never ending misconception. Anyway, I think this will be ok and if not, I can always move it, eh?
I like this location for wiring, for fuel leak inspection, for less heat, less vibration. Besides, red and black look cool together....

 

[alpinelakespilot2000]

Even if you do plan to use it to measure total fuel consumption, it isn't a problem. The error is small enough (at least on the RV-10) and the electric pump runs so infrequently that the net effect on the fuel consumption data is inconsequential.

I'm working through this issue right now. I have my floscan after the fuel selector and before the boost pump. Rob's point is probably correct for times when you're flying cross-country with the fuel pump off the vast majority of the time. However, if you mix in any time doing pattern work, where the pump is always on, your totalizer will likely be significantly off the next time you do a fill up. In my case, my fuel flow will read about 2gph higher with the pump on then when the pump is off.

Also, while the transducers come with a default or preliminary k-factor to program into your EFIS, you still have to adjust/calibrate it for your particular installation. It's hard to figure out a new, more correct k-factor if at any point the boost pump was on between fill-ups. The point I'm trying to get at is if you do not do this calibration and do it accurately, your EFIS will not necessarily be showing actual fuel flow even when the fuel pump is off.

The good news is that if you try to calibrate the k-factor for a tank of gas in which the pump was on at any time, your totalizer will error on the conservative side (read less than what you really have).

In retrospect, I would have put my floscan forward of the firewall. Anyway, just some things to think about.

 

[rleffler]

When mounting the red cube in the RV-7A tunnel, is it necessary to make a physical connection of the cube to the fuselage floor, or will the 3/8 fuel tubing provide a stiff enough mount? I have 1/8" foam insulation on the floor and the cube sits on top of the thin foam. It seems pretty rigid this way, but I am curious about the experts opinions.

I can't comment on the applicability in a RV-7, but in the RV-10, the red cube was intended to be mounted on VA-188, which raises the cube about a 1/4" off the tunnel floor. This would be a more secure method if there is room for the mount in the RV-7.