flo-scan or FT-60

[Greenley]

I am working on the forward fuselage floor. There are two options for installing the platenuts on the VA-188 Flo-Scan mount bracket, one for the flo-scan and one for FT-60 (red cube?). What are pros and cons, does it make a difference with which EFIS I use (leaning toward GRT)? Just mount the bracket later?

Thanks for any info.

 

[Auburntsts]

Go FT-60

That's easy -- the GRT, AFS, and Garmin G3X sensor kits all use the FT-60 (aka the Red cube). I think Dynon can supply either the Floscan or FT-60.

What's harder is choosing where to mount it-- per the plans in the tunnel or FWF downstream of all the pumps. I'm going FWF, but many have chosen to use the stock location. There's a number of threads on the subject both on VAF and on Matronics so I won't rehash the pros and cons here. YMMV.....

 

[flion]

My Garmin 900X uses the Floscan. But I just put platenuts for both options in the bracket when I built the fuselage floor because I wasn't sure at the time which I'd be using. You can make a spacer for one of the platenuts that share a rivet or re-orient the platenuts slightly.

 

[Strasnuts]

G3X can use either one

My G3X system can accept either. I prefer the red cube.

8.2.11 Fuel Flow
Electronics International FT-60 (Red Cube) - This sensor is applicable to all engines. Refer to the
Electronics International FT-60 Flow Transducer (Red Cube) document # 1030032 for installation
guidance.
General Installation Guidance (Floscan Series 200) – This sensor is applicable to all engines. The
below is taken from the Floscan Series 200 Flow Transducer Application Notes:
1. The inlet and outlet ports in series 200 flow transducers have ¼” NPT threads. Use only ¼” NPT
hose or pipe fittings to match. When assembling fittings into the inlet and outlet ports, DO NOT
EXCEED a torque of 15 ft. lbs. (180 inch lbs.), or screw the fittings in more than 2 full turns past
hand tight WHICHEVER HAPPENS FIRST. Floscan Instrument Co., Inc. will not be
responsible for cracked castings caused by failure to use ¼” NPT fittings, over-torquing the
fittings, or assembling them beyond the specified depth.
2. A screen or filter should be installed upstream of the flow transducer to screen out debris which
could affect rotor movement or settle in the V-bearings. As turbulence upstream of the transducer
affects its performance, there should be a reasonable length of straight line between the
transducer inlet and the first valve, elbow, or other turbulence producing device.
3. Install the flow transducer with wire leads pointed UP to vent bubbles and insure that the rotor is
totally immersed in liquid. For maximum accuracy at low flow rates, the transducer should be
mounted on a horizontal surface.
Some additional mounting considerations should be noted as follows:
1. When installing the NPT fittings into the transducer, use fuel lube such as EZ TURN © or an
equivalent thread sealer. Teflon tape should NEVER by used in a fuel system.
2. To minimize inaccuracies caused by turbulence in the fuel flow, the sensor should be mounted
with approximately 5-6” of straight tubing before and after the sensor. If special circumstances
exist that prevent an extended length of straight tubing before and after the sensor, then a gently
curved hose may be acceptable. 45 degree or 90 degree elbow fittings should NOT be used
immediately before or after the sensor.
3. Specific sensor mounting location is left to the builder. Ideally, the sensor should be placed prior
to the fuel distribution device (carburetor or fuel injection distribution device). On a Continental
fuel injected engine, the transducer must be located between the metering unit and the flow
divider valve.
4. Sensor wires should be connected to the appropriate inputs on the GSU 73 as referenced in the
G3X interconnects in Appendices G and H.
G3X Installation Manual – Engine Sensor Installation and Configuration Page 8-17
190-01115-01 Revision E
8.2.11.1 K-Factor for Floscan 201B-6
The Floscan 201B-6 (201-030-000) fuel flow sensor ranges from 28,000 to 31,000 pulses/gallon.
The G3X default K factor for the 201B-6 is set to 29,500 pulses/gallon. Some Floscan fuel flow sensors
come with a tag that lists the K factor number measured during unit calibration (see Figure 8-16).
NOTE
If the Floscan tag shown in Figure 8-18 is lost, the serial number of the Floscan sensor
can be supplied to Floscan to obtain the calibrated K factor value.
Figure 8-18. Example Floscan Fuel Flow Sensor
The tag shown in Figure 8-18 lists a K Factor of 16-2890. The first two digits (16) represent Gallons Per
Hour, while the last four digits (2890) represent the number of electrical pulses (divided by 10) output by
the sensor per gallon of fuel flow. The numbers on the tag are used in determining the K-Factor to be
entered as part of the Fuel Flow Calibration described in Section 8.3.3. To determine this number, a zero
should be added to the four digit number on the tag. In the example above after adding the zero to 2890,
the resulting K-Factor to be entered on the Fuel Flow Calibration page would be 28900.
8.2.11.2 K-Factor for Electronics International FT-60 (Red Cube)
The G3X default K factor for the FT-60 is set to 68,000 pulses/gallon. No sensor specific calibration is
required for the FT-60 but variations in the installation can affect the K factor. Reference Electronics
International document #1030033 and Section 8.3.3 for additional information.

 

[Auburntsts]

Let me clarify my previous post. Based upon my research, Dynon, GRT, and Garmin G3X EFIS systems all will work with either transducer – FloScan or FT-60. AFS appears to support only the FT-60. However, if you buy the sensor kit for GRT or AFS systems, the FT-60 is what is included in the package, at least according to the websites. My G3X sensor package came with the FT-60 so at least I can establish that as fact.

The safe bet is to follow Patrick’s advice and simply rivet on both sets of nutplates if you are unsure of which system to use and/or where you will eventually mount it. For what it’s worth I used that same bracket in a slightly different location to mount my EFii boost pump’s fuel filter.

 

[Greenley]

Thanks for all the input, sounds like either put in both sets of platenuts, or probably safe to setup for just the FT-60.

 

[N402RH]

Let me clarify my previous post. Based upon my research, Dynon, GRT, and Garmin G3X EFIS systems all will work with either transducer ? FloScan or FT-60. AFS appears to support only the FT-60. However, if you buy the sensor kit for GRT or AFS systems, the FT-60 is what is included in the package, at least according to the websites. My G3X sensor package came with the FT-60 so at least I can establish that as fact.

The safe bet is to follow Patrick?s advice and simply rivet on both sets of nutplates if you are unsure of which system to use and/or where you will eventually mount it. For what it?s worth I used that same bracket in a slightly different location to mount my EFii boost pump?s fuel filter.

The AFS systems can use the FloScan or the FT-60. If you have an injected engine you really want to install it in the line between the fuel servo and distribution block on the top of the engine. Electrically both transducers have the same signal level, the FT-60 puts out more pulses per gallon.

Rob Hickman
Advanced Flight Systems

 

[rjtjrt]

I guess more pulses per gallon means greater accuracy?
If so, is there any difference in real world accuracy?

John