Dynon Fuel Flow Sensor

[RVG8tor]

I need to run my purge return line but before I do I want to find a location for the Flo Scan fuel flow sensor used in the Dynon instruments. There are two large holes for bolting this small item to something but then I thought I have seen it mounted with fittings and just in line with the fuel line, no support provided.

Any RV8 or 8A builder care to share with me where you mounted the flow sensor, and pictures sure would be helpful. If you don't want to post the pictures you can email me with the address in my profile. Thanks for the help

Right now I think I want to make a loop coming out of the boost pump back through the flow sensor then back forward to the firewall bulkhead fitting. The flow would do a large 360 degree reversal coming out of the pump. One thought was to mount the flow sensor right to the bulkhead fitting. The only thing the Dynon instructions say is to make sure it is after the boost pump and filter.

 

[RV8R999]

I just went through the same drill, although I'm not using a fuel injected engine so I don't have as much plumbing. I still don't know how to EASILY post pictures here but I can tell you I mounted my flo scan as close to the firewall fitting as I could get, which ended up about 1.75" needed to allow for my flaring tool to fit with the fittings installed. I made a support bracket with some scrap material mounted to the floor and bolted to the underside of the Flo scan..took about 30 minutes total.

 

[jcbarker]

fuel flow sensor mounting

Mike,
Here's a picture of where I mounted mine. 90 degree fitting (steel) at the firewall. Straight section of tubing (approx 6") Made a bracket from some angle which I mounted to the fire wall.
Hope this helps,
John

 

[Mathew Sharp]

There are two large holes for bolting this small item to something but then I thought I have seen it mounted with fittings and just in line with the fuel line, no support provided.

You do NOT want to rigid mount the transducer to the motor (any part) using just a fitting. It is a huge safety issue. The fitting could theoretically fatigue and break. You absolutely need to have flexible line on both sides of the Floscan 201B or the EI FT-60 (that Dynon now utilizes).

After manufacturing/supporting flow instruments for a good number of years we have seen that flow transducers accuracy is typically better when mounted after both fuel pumps. They simply seem to prefer to have fuel pushed through them, not pulled through. The truth of it though is that many installation drawings still read as though we were still using the older Floscan 201 transducers. I have seen installs that mount the transducer between the pumps with claimed success. The Floscan units were much more sensitive in regards to mounting location, angles of fittings in and out, and attitude. Our new design will tolerate a lot more. Frankly we don't care if the thing flows straight up, or if you put 90-degree fittings in and out (FT-60 only) of the transducer. Just don't mount it upside down or flowing sharply downhill.



Hope this helps,

Matt Sharp

 

[RV8R999]

if you look closely he has a the transducer mounted to the firewall and a flexible hose connecting it to the engine driven fuel pump. No safety issue here...

 

[N8RV]

Nemo, I had a heck of a time figuring out where to mount that blasted thing. The instructions suggested that it have several inches of straight tubing before AND after it, and that it be downstream of the electric fuel pump.

It's been long enough ago that I don't really remember WHY I chose where I mounted it -- between the fuel selector valve and the electric boost pump -- but it works just fine. It may not be the ideal place to mount it, but it's protected down there from being kicked and works fine so far.

 

[Pilottonny]

After the throtle body.......

I have a return line from the throtle body back to the tank, so I had to install the Flo-Scan in the line from the throtle body to the "spider". I have a straight piece of hose on the 90? fitting that is coming out of the throtle body, than the Flo-Scan and than a hose going straight for a couple of inches and bending up between the cylinders to the "spider". The sensor is not attached to the engine. I covered it with a piece of large dia. Firesleeve and two hose clamps, that clamp on the firesleeved hoses on either side, to keep it from getting hot.

Regards, Tonny.

 

[RVG8tor]

This is what AFP recommends

I have a return line from the throtle body back to the tank, so I had to install the Flo-Scan in the line from the throtle body to the "spider". I have a straight piece of hose on the 90? fitting that is coming out of the throtle body, than the Flo-Scan and than a hose going straight for a couple of inches and bending up between the cylinders to the "spider". The sensor is not attached to the engine. I covered it with a piece of large dia. Firesleeve and two hose clamps, that clamp on the firesleeved hoses on either side, to keep it from getting hot.

Regards, Tonny.

I called AFP and spoke to done, he said to intall it in the line between the between the fuel servo and the spider on the top, you want it in the metered fuel line where his exact words.

Matt,

I am curious about the EI FT60, I just bought my FltDek 180 in April with the sensor package and the Flo Scan is the sensor Aircraft Spruce sent with my sensor kit. Should I have gotten another sensor or will either one work. I wonder if they would swap me the FT-60 for the Flo Scan?

 

[Brantel]

I am curious about the EI FT60, I just bought my FltDek 180 in April with the sensor package and the Flo Scan is the sensor Aircraft Spruce sent with my sensor kit. Should I have gotten another sensor or will either one work. I wonder if they would swap me the FT-60 for the Flo Scan?

Mine came with the FT-60 red cube. I think it is luck of the draw on what you get. Personally I like the FT-60 much better than the FlowScan. The Dynon system will work with either one. They have them both in their install manual. Not sure why they package both ????

 

[Pilottonny]

Installation picture....

A picture of my Fuel flow sensor (well,.... you do not actually see it, it is wrapped in the fire sleeve).

Fuel coming from the throtle body, a small piece of straight hose, the Flow Scan sensor, than the hose going up to the spider. Lots of heat shields on the exhaust pipes, to keep the throtle body and fuel lines cool!

Regards, Tonny.

 

[Andy Hill]

We put the Fuel thru' Firewall line as far outboard as possible, giving enough distance along the firewall for the sensor and the required distances.

As discussed above, if you want it to be accurate, it should not be between the fuel pumps. Ours is, and overreads by ~50% with the Electric Pump on. Not a big issue if all you use it for is leaning / monitoring in the cruise. But if you want to "totalise" the Fuel Flow for Fuel Used than it will probably need to go elsewhere...

Andy
RV-8 G-HILZ