Fuel Flow Transducer location

[Captain Avgas]

I honestly don't understand the mentality that exists in the garage-built crowd anymore where something you read must be followed as gospel, and alternative ways of making things are frowned upon just because someone says there's no data to support what one is doing. EAA- EveryAirplaneAlike.

Bob, this is a delicate situation because I certainly don't want to discourage builders from putting forward ideas and you are to be commended for contributing.

However there is a lot to be said for encouraging the adoption of techniques that have been proven successful in mainstream general aviation over time. This is particularly true of FWF installations where failures can be particularly disasterous.

One of the major advantages of the Experimental category comes from the ability to "experiment".....but that is also its weakness. The use of internet forums to source construction advice can be invaluable...but it can also be dangerous. It's a double edged sword because there is so much advice being proferred on adhoc and untested installations.

Look at the recent Mark Chamberlain thread. http://www.vansairforce.com/community/showthread.php?t=19711

This gentleman is probably lucky to be uninjured because he has had 2 engine failures and forced landings in recent months. The first, because he installed an electronic ignition system with virtually no track record. The second, and most recent, because he experimented with using a rubber mat to seal his air filter...and it came loose and was sucked into the throttle body.

We owe it to ourselves, to our passengers, and to the Experimental movement at large, to do the proper research that will allow us to use time tested and proven construction principles. As they say....with freedom comes responsibility. Because without the latter, the former can quickly evaporate.

 

[rlo1]

My fuel flow transducer (Flowscan 201B) has been between the fuel selector and the boost pump in the cockpit of my -6 for almost 14 years and works great.

This is what I was thinking about doing. I am planning on an ECI FI Motor with return. Mel's setup is simple and a much safer option (IMO).

Two questions:

Q1: Am I correct to assume that return flow is not occuring all the time?

I feel that I only need accurate fuel flow readings when tweaking mixture (LOP) and running straight and level cross country thinking about my next fuel stop.

Q2: Is this how others feel about the value of fuel flow readings?

-Ron

 

[Yukon]

This is what I was thinking about doing. I am planning on an ECI FI Motor with return. Mel's setup is simple and a much safer option (IMO).

Two questions:

Q1: Am I correct to assume that return flow is not occuring all the time?

I feel that I only need accurate fuel flow readings when tweaking mixture (LOP) and running straight and level cross country thinking about my next fuel stop.

Q2: Is this how others feel about the value of fuel flow readings?

-Ron

Ron,

Installing the flowscan upstream of the filter is not approved by the manufacturer. Debris can plug it and possibly interrupt fuel flow.

 

[frankh]

Very acurate

This is what I was thinking about doing. I am planning on an ECI FI Motor with return. Mel's setup is simple and a much safer option (IMO).

Two questions:

Q1: Am I correct to assume that return flow is not occuring all the time?

I feel that I only need accurate fuel flow readings when tweaking mixture (LOP) and running straight and level cross country thinking about my next fuel stop.

Q2: Is this how others feel about the value of fuel flow readings?

-Ron

The flowscan flow meter is a very accurate unit. Now if you have a constant return to the tank then all bets are off.

If you want accurate flow used by the engine then you will need 2 flowmeters, one in the feed and one in the return.

Matronics sell a little black box that will subtract one reading form the other and the output of this unit can be read directly by a Dynon or similar.

Now if you only use the return for a hot start purge then the amount you "loose" thru the return is miniscule so you won't need the second flowmeter.

But if your return is flowmeter is running all the time then you'll have to measure it to get an accurate consumption.

My Dynon uses the flowmeter to calculate how much fuel has been used and personally I would much rather use this method than look at the float guage in the tank.

The tank guage is simply a backup to spot large fuel leaks and to balance the useage from each tank.

Frank 7a

 

[Mel]

Ron,

Installing the flowscan upstream of the filter is not approved by the manufacturer. Debris can plug it and possibly interrupt fuel flow.

I have filters ahead of my transducer. I have a filter between each tank and the selector valve.

 

[rlo1]

Mel,
Do you ever have to change/clean the filters?? If not, installing them in the fuse next to the center spar (L/R) seems reasonable.

I would still use a gascolator for water collection reasons.

Can anyone speak to the ECI FI system? When is the return used?

-Ron

 

[Mel]

I clean the filters at annual condition inspection. I have a small cutoff valve just ahead of each filters. I do have a gascolator on the firewall.

 

[lorne green]

FloScan 201B

I's time to order a fuel flow transducer. The FloScan 201B that Dynon offers seems to be popular. Here's my question.

Our fuel lines are 3/8", the 201B fittings offered by Dynon are 1/4" NPT. This will cause flow a restriction.
I've viewed some builders' web pages and seem to see the tranducer's orifice as about 3/8".
Dynon's order sheet only shows 1/4" fitings. What? Just change the fittings out for 3/8"?
Anyone care venture a guess as to the fitting callouts for the this transducer?