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azonic75

Well Known Member
I've struggling with a place to put the red cube.
Opinions vary greatly and in the end it doesn't seem to matter that much.

This is what I have come up with.

redcube3.jpg


redcube2.jpg


It's a three inch length from the fire wall fitting to the cube, nine inches from the cube to the fuel pump.

Cube will be attached to the firewall on a bracket. Thoughts, comments....

Kai
 
Since you have already installed it, I'm sure you will find when you fly it but I personally don't know anyone that had to move it when installed on the pressure side of the engine driven pump but do know several that had to move it from the suction side due to different readings when the boost pump was turned on or off. Larry
 
Tell me about the firewall penetration fitting. It looks like just a steel ninety degree fitting.

Making it a bulkhead fitting would give you the support there that you need.

I also located my red cube after both pumps as others have mentioned for the same reasons. I copied a friends flying -7 an his fuel metering is spot on.

:cool: CJ
 
Thanks

It is a bulkhead fitting going through the firewall, supported on the cockpit side.

Placing it before the fuel pump and servo while maybe not recommended seems to work for many people though clearly boost pump flow have a small effect.

Thanks guys
 
I spent a month and a half in my spare time researching ideal mounting locations. What I learned is that the "ideal" location is after all pumps. However, very few people have mounted it there. According to many posts here on VAF, while the reading does rise when your electric pump is on, it does not seem to significantly affect the fuel levels reported over the life of a tank of gas.

In the end, I placed mine as you did, between the two pumps. I don't believe that the extra complexity in plumbing is worth the benefit of having the flow read properly in the short duration my boost pump is engaged. So far, the total burned as recorded by my fuel gauge has matched what I put in at each fillup within 1L, which is good enough for me.
 
Flow Meter Transducer on FI engines

To give correct indication of fuel flow under all conditions (boost pump on or off) the flow meter Transducer should be located in the metered fuel line (that is between the fuel servo and the flow divider. Never put the flow transducer on the suction side of any pump.

Don
 
Kai--
Many RV10's have their flow transducers mounted in the tunnel, downstream from the boost pump, and up stream from the mech. pump. I havent heard of anyone having issue, although I may be wrong. I think the desired location in downstream from the mech. pump. I've even seen applications where they are mounted between the servo and the flow divider (spider).
This may be one of those 'experimental' aircraft deals that you plumb it, test it, and see the results. Moving it at a later date isnt a big deal.
Tom
 
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