Install older Vans cap fuel sender?

[FlyGuy65]

Working an older (2003) RV-7 slow build, but this probably cuts across a few different models, so here goes...

Bought the fuel capacitance sender option with the wing kit. Now it's getting near time to start working on the tanks. Don't want to start the 'float vs cap.' debate (I liked the idea someone posted of having both, just in case!).

My question are:

- whether or not to install the Vans cap. sender which I already have, or are there other newer units which are vastly superior.

- will my older sender units even be compatible with newer glass instrumentation and converter units?

- any thoughts from folks who have the original Vans units installed?

At this point I consider the $ spent on the Vans units as long since gone, but I do have them and the plans from Vans for them: my goal is to have a reliable system with a minimum of mods from the plans - this project has taken long enough!

Thanks in advance!

PS don't plan on mixing fuel types, and do plan on getting fuel flow transducer when the time comes

[Jpm757]

I have the Van's fuel capacitance system in my -7, and am using the Dynon BNC style converters to connect to my Dual AFS5600 system. I calibrated the system in 2 gal. increments in both flight and ground attitudes. In comparing fuel quantity with fuel used/remaining I have found the fuel levels to be consistently within 1-2 gals. per tank. My fuel computer calculations are dead on.
Red cube located between engine pump and servo, 100LL fuel only.

[FinnFlyer]

With an outboard rib plate and inboard rib plate you should be able to get readings from full to empty.

In my old RV-3 I made my own "sender" (capacitor): tube within tube (plastic spacers isolating the inner tube from outer tube) running diagonally from lowest (inboard) to highest (outboard) points in the tank through holes in the ribs. Outer tube should be electically bonded to the tank. I used a screw through isolating nylon spaces through the root rib as my "connector" to the inner tube (your two plates) instead of a BNC connector.

I would recommend installing a third plate near the inboard bottom that will always be covered with fuel. It should have its own (BNC) connector, not connected to the other two plates. Just in case some smart guy comes up with a converter with a second (compensation/calibration) input that is used to measure the dielectric constant of the actual fuel in the tank. Then you can mix and use any current and future fuel -- 100LL, MoGas, Swift ...

Finn

[RV7A Flyer]

Originally Posted by FlyGuy65

Working an older (2003) RV-7 slow build, but this probably cuts across a few different models, so here goes...

Bought the fuel capacitance sender option with the wing kit. Now it's getting near time to start working on the tanks. Don't want to start the 'float vs cap.' debate (I liked the idea someone posted of having both, just in case!).

My question are:

- whether or not to install the Vans cap. sender which I already have, or are there other newer units which are vastly superior.

- will my older sender units even be compatible with newer glass instrumentation and converter units?

- any thoughts from folks who have the original Vans units installed?

At this point I consider the $ spent on the Vans units as long since gone, but I do have them and the plans from Vans for them: my goal is to have a reliable system with a minimum of mods from the plans - this project has taken long enough!

Thanks in advance!

PS don't plan on mixing fuel types, and do plan on getting fuel flow transducer when the time comes

I have them on my 7, and love them. Never had any problems with them. What I *did* have problems with was the "stock" Dynon C2V converters, which could not take advantage of the full 0-5V range, utilizing only a tiny portion of it in the middle, so the mid-range readings were for s**t. Switched to the Princeton 2-setpoint converters almost immediately, and they've been great for over 700 hours now. (With the Princeton converters, you empty the tank, and set that as 0V, fill the tank, set that as 5V, *then* do the 2 gallon increments for the Dynon EFIS, or whatever your EFIS calibration process is, so you're using all of 0-5V).

I don't know why Van's quit selling these...they're dirt simple, no moving parts, cover the full range of fuel at any attitude equally accurately. Heck of a nice system, IMO.