fbpx

 

I'm relatively new to the site.  I'm building a RANS S-19 with a 912ULS.  The fuel return line goes to the gascolator, not the fuel tank.  I know Rotax recommends returning the line to the tank but the RANS S-19 design returns it to the gascolator.  Where do I mount the FT-60 fuel flow transducer?  The FT-60 manufacturer says to install it after the last fuel pump.  I believe that would be after the engine-driven pump and before the carbs.  That pretty much says that it will be mounted in the engine compartment where it is hot and vibrates.  Many posts say not to mount this delicate sensor in the engine compartment.  I have an electric backup pump mounted in the cockpit after the fuel tank selector valve and before the gascolator in the engine compartment. 

Can I install the FT-60 in the cockpit after the electric backup pump and before the gascolator in the engine compartment?  I also have left and right Aerolab gascolators located at the fuel output line for each tank.  So those will act as filters before the electric backup pump and the FT-60.  Regarding the discussions about the flow readings being inaccurate because of the return line I don't think this will be an issue if the FT-60 is installed before the return line to the gascolator in the engine compartment. 

I guess my two concerns would be 1) why is it recommended to install the FT-60 AFTER the last fuel pump, and 2) the FT-60 data sheet says that the fuel line on the output port must not drop DOWN after it exits the transducer.  But I read that others are installing the FT-60 in the cockpit--how does the fuel line not drop down?  I have also read posts that say the fuel lines to the FT-60 must be horizontal for at least 6 inches.  Maybe these questions should also be addressed to the FT-60 manufacturer?  I apologize for re-hashing what has been posted about before but many of the posts are in reference to the fuel injected engine (with high flow rates that must be returned to a tank and not the gascolator). Thanks for your comments.

  • Re: FT-60 Fuel Flow Transducer on 912ULS

    by » 3 years ago


    Even though Rotax doesn't recommend the gascolator option there are a few companies like Flight Design that do route the return line for the carb engine back to the top of the gascolator. The carb engine  doesn't recirculate as much fuel as the fuel injected engine.


    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell


  • Re: FT-60 Fuel Flow Transducer on 912ULS

    by » 3 years ago


    Return line aside, any comments on placement of the FT-60?


  • Re: FT-60 Fuel Flow Transducer on 912ULS

    by » 3 years ago


    I put it after the manifold, before the left carb, and configured the Garmin to half the K-factor (for multiplying the measured flow), assuming equal fuel consumption by the carbs.

    Ran


    Thank you said by: Michael Tucker

  • Re: FT-60 Fuel Flow Transducer on 912ULS

    by » 3 years ago


    I have a RANS S-12 with a 912UL.  I mounted my Red Cube after the electric aux pump and before the engine driven pump. This was to keep it away from the heat and vibration above the engine.

    At first I could not get consistent fuel burn readings. After much thinking, we found the solution (hat tip to Don Forse of Wichita!)


    I am very attentive at supporting all my engine hoses with standoffs. I want them secure. The problem in the case of The Cube was that my careful standoff method was transmitting too much vibration from the frame into said Cube. I cut away two of the standoffs adjacent to it so that The Cube is now suspended between approx one foot of fire-sleeved fuel line on each side. Ever since doing this it has functioned great. 
    The Cube requires a bit of isolation and the hose “cushions” it.

    Now, after applying the fix, the fuel computer reads within .25 to .5 gallons on trips with total fuel burns of 13 to 15 gallons. I’m happy with that.


  • Re: FT-60 Fuel Flow Transducer on 912ULS

    by » 3 years ago


    Thanks very much, Brian...  makes sense!


You do not have permissions to reply to this topic.