Fuel Flow Transducer

Can anyone elaborate on the differences between the Flow Scan vs the EI FT-60 "Red Cube" series of transducers? Are there any merits of using one over the other? Seems the Flow scan is made from cast metal vs machined stock for the FT-60? Would think the machined metal would be preferred.

Thanks,
Greg

Search on "red cube" - there were some posts a while back.

Fallible memory says they work about the same, but that the red cube is less susceptible to location (e.g. near bends in the fuel line) and orientation.

I have the one supplied by Dynon (not the red cube) and it works just fine.

cube

The red cube from EI is now standard on dynon i believe. It is "apparently" much better than the flowscan. It does seem well built and the support I got when I emailed for further install info (none came with dynon kit) was great. I have heard of a few builders getting the old one with the engine kit from acs etc, I believe that is just old inventory being cleaned up. I specifically requested the red cube in the kit and it was. Again search the forums there are several good install pics.

I have a flowscan on my RV-8 with GRT EIS-4000 and it works impeccably. After dozens of fill-ups it has proven to be remarkably accurate.

I'm not sure what more the red cube could do. I've not heard of any particular problems with either one.

Red cube "FT-60"

I have a concern with the install of the transducer per Dynon's instructions. The transducer should be the last thing in line before the fuel enters the engine. Mounting it between two pumps as they have described is wrong. You do not pull fuel through this transducer, it needs to be pushed and on the RV10 kit the fuel line from the electric pump the mechanical is a AN6 line, that would require you to restrict the fuel flow to the engine driven pump. I think this issue needs to be addressed before someone has a problem.

XJET said:

You do not pull fuel through this transducer, it needs to be pushed.

Click to expand...

Ideally this is best. However, I have been "pulling" fuel through mine for over 17 years and it has proven to be extremely accurate. My transducer is mounted just after the selector valve in my -6.

Is yours a Flow Scan or the EI FT-60? The manufacturer told me on the 60, it would cause cavitation and erratic reading.

I started out with the Flo-scan and later switched to the "red cube". Both seem to work fine.

EI's FT-60 vs FloScan 201B:


Dynon, Advanced Flight Systems, UMA, and others now exclusively use the FT-60.

General differences:
The Red Cube FT-60 from EI has considerably less pressure drop across it than does the FloScan 201B. Also, the overall accuracy and linearity of the FT-60 is superior. The FT-60 design vacates bubbles and is not nearly as susceptible to debris as the FloScan. Additionally, rotor pin is mounted on sapphire jewelled bearings that are clearance matched on every unit resulting in a single K factor for every unit.


FT-60/FloScan 201B

Flow Range: .6 to 70+gph / .6 to 60 gph
Pressure Drop: .6 psi @30 gph and 2.3 psi @60 gph / 1.2 psi @60 gph and 4.8 psi @60 gph
Weight: 5.26oz / 5.33 oz
Chamber Design: Flow path is straight through / Helical (spiral) flow rate.
K Factor: 68,000

What's the pressure drop at oh.. say... 7-8gph? Is there a significant difference at that flow? Should we care about pressure drop at 60gph when flying an RV?

@ 7 gph the FT-60 only looses .03 psi
@ 8 gph .04 psi

Presuming we are talking 100LL @ 59 deg F (6.02 lbs)

EI FT-60 VS Floscan 201B-6

The main differences are weight of the units, pressure drop and the K factor. Performance is similar. See below:

FloScan 201b6 Specifications:

Flow Range , Gasoline: 0.6 ? 60 GPH, #2 Diesel: 3.0 ? 60 GPH
Approximate K Factor (Pulses/Gallon @ 16 GPH):28,000 ? 31,000
#2 Diesel: 28,000
Pressure Drop, Gasoline:1.2 psi @ 30 GPH, 4.8 psi @ 60 GPH
#2 Diesel: 1.5 psi @ 30 GPH, 6.0 psi @ 60 GPH
Repeatability Between Measurements: 1/2% @ 16 GPH
Working Pressure: 200 psi
Temperature Range: -65? / 100?C
Bearing Life Expectancy: 10,000 hr. min.
Electrical Specifications:
12-15 VDC between RED (+) wire and BLACK (-) wire. 30 to 50 mA at 12 VDC.
weight: about 2 Oz.

-------------------------------------------------
EI FT-60 ?Red Cube? Specifications:

Flow Range , Gasoline: 0.6 ? 70+ GPH,
Approximate K Factor (Pulses/Gallon):68,000
Pressure Drop: 0.5 PSI @ 28 GPH, 2.0 PSI @ 56 GPH
Repeatability +/- ?%
Working Pressure: 100 PSI psi
Temperature Range: -65? / 125?C
Bearing Life Expectancy: 10,000 hr. min.
Electrical Specifications:
8-30 VDC between RED (+) wire and BLACK (-) wire. @ 14 mA
weight: 5.26 Oz.

I wonder how important the pressure drop issue is. When fuel flow is highest (takeoff) I have the fuel boost pump on for my 180 hp IO-360. There is plenty of pressure upstream of the fuel flow sensor. Fuel flow is I think 16 gph at WOT so the pressure drop is probably less than 1 psi with 40 psi pump outlet pressure.

I have the FloScan and have not had any problems after 1 year and over 100 hours of flying with it. I think this is a case where we have two very good devices to chose from both of which do a remarkable job.