Fuel flow metre

[Guest clemair]

Has anyone installed a fuel flow meter in a J230? If so, what model would you recommend and were there any dramas installing or calibrating? one last thing, is it as accurate as you thought it would be?

 

 

[Captain]

I have one in my 230 as part of the Dynon 180. I located it downstream of the header tank, isolation valve, fuel pump and fuel filter.

 

 

 

It is a series 200 Flowscan unit that has an impeller in the fuel line and can be seen at http://www.floscan.com/html/blue/aviation.php.

 

 

 

That unit was supplied by Dynon with a calibration number and it can be readily altered to suit the specific installation. Once calibrated I find it very accurate to what needs to go into the tanks after each flight.

 

 

 

Hope that helps.

 

 

 

Regards Geoff

 

 

 

[Guest clemair]

Thanks Geoff, I contacted Dynon and as I am using the EFIS I can't connect fuel flow equipment to read from this. I will need to install a completely independant guage and sensing unit.

 

 

[Captain]

Did you see the Flowscan gauges on their website too?

 

 

[jeffcb52]

Clemair,

 

I have use a fuel mizer in my J200 and it was good. Accurate once calibrated.

 

I replaced it with a JPI 450 which has the advantage of connecting to the gps, as well as showing fuel flow at the same time as the other normal totals shown by mizer.

 

The first JPI went mad and was replaced under warranty. New one works well. Once again it all about calibration, and working from the total which is reset at each filling of the tanks.

 

Regards

 

Jeff

 

 

[Guest clemair]

Thanks Jeff, I have been researching the JPI 450 and seem pleased with what I have read. Nice to get some feedback from somebody who has used the item rather than the speel a company will give you. Was it a simple thing to callibrate or a bit of trial and error. You mentioned hooking up to GPS, I am using a Garmin 296, don't suppose you know if it will work with that unit or not?:big_grin:

 

 

[Guest brentc]

I was going to buy one of these and was later glad that I didn't. I was flying back from Narromine when my J400 was fairly new. The rudder was slightly mis-aligned and I wasn't on the ball with the rudder as much as I should. As a result my right-hand tank almost completely drained out the vent and was lost into the ether. My engine spluttered and I landed immediately because I had no or little fuel. Had I had a fuel-mizer or similar it would have said that I had more fuel left than I actually did and I could have continued on and run out of fuel completely.

 

Nowdays I use a timer, known fuel burn and the manual guages to be safe and it's working well for me.

 

That being said though, they are a good device for recording your fuel burn and they are handy.

 

 

[Guest clemair]

I take your point, it is not good practice to rely soley on one source of information, good ol fasioned arithmatic should still be used in conjunction. What I would be interested to see is when I am flying at 9500' what is my fuel burn and then how does this differ from 4500'. If you fly at a constant 2850rpm then at sea level there will be a different throttle position to when you are at 9500. I would like to be able to detect how well the carby is compensating and as it may be possible to fly at different levels on the one trip a more accurate fuel calculation could be obtained during each sector. I too am very wary of keping that ball right between the goal posts. When I picked my aircraft up from the factory I saw that the right tank was getting pretty low and the left was still around 3/4. I did not have the faith at that point that the header tank would do its job so landed at an unsheduled spot to fill up. No loss of fuel overboard. An interesting thing is that my anologue skid ball differs slightly to my EFIS skid ball and if I fly with reference to the EFIS i will draw from the tanks more evenly.

 

Cheers Danny

 

 

[Guest J430]

Couple of tips.......

 

your Dynon is way more accurate than you would believe.

 

Fuel flow should be around 23LPH in the cruise at any level, what changes with the height is the amount of throttle opening.

 

the Jab is like most planes they cross feed from the right a bit in flight. I wonder if the small amount of engine offset has something to do with this, as I know one operator squared his up and his J430 flies a lot straighter and more efficiently now. I am going to look at it too next service.

 

To check the fuel level in flight and without the gauges being affected by fuel draw (old sight glass types), turn the tap off, ensure you are in level flight and skid ball centred and then read the gauge. Remember to turn it back on again too:keen:

 

J

 

 

[Yenn]

This loss of fuel, caused by flying out of balance sounds like a problem to me. Do the vents cross over to the opposite wings, which should prevent fuel loss happening. Just think, the port wing vent runs to the stbd wing, so if the port wing is low the vent is high.Vice versa for stbd.

 

Of course it may be like the lack of tap at the tank, just a poor design feature.

 

 

[Guest clemair]

I see what you are saying Ian, I have never experienced it where fuel is lost from the aircraft, just using from the stb tank and very little used from the port at times. I am still trying to figure it out, maybe if the vent tubes on the fuel caps are not exactly aligned with the airflow, this would cause a pressure differential between the tanks and thus causing the tank with the higher pressure to feed the header tank first. (To the eye, they look right). I am a simple mind, but tell what you think.

 

Danny

 

 

[Guest brentc]

Mine feed unevenly all of the time and that can be either tank first, but I've never had one not feed at all as they both go down, just as different rates.

 

 

[Alan]

Yes I would concur, mine always seems to drain the tanks unevenly and does not seem to favour one tank over the other. I used to do some ridiculous crabwise flying to attempt to move the fuel to balance them out. I now just keep an eye on them and frown! But despite the red light indications I have (so far) never had a real (cough splutter) fuel feed problem. - Dip the tanks calculate the usage conservatively and use the gauges to show nothing is leaking.

 

Talking of fuel leaking, at the last service I noticed heavy fuel staining of the protective hose where the fuel pipe connects to the carb. The hose clamp would only take half a turn more before becoming very tight. Despite much running and leaving the electric pump on I have seen no further leaks. Mine is a factory built LSA J230 anybody else had trouble here.

 

Alan

 

 

[mlpinaus]

Fuel Stains

 

Yes, my j230c showed stains at the connection to the Dynon fuel sender. Its under

 

the cover at the back. Increased the clamp presure. Seemed to fix it. Keep an eye

 

on it though. That fuel metering stopped for a while due to a tiny bit of crap under

 

the impeller. 0 litres an hour for a while there..

 

Marcus

 

 

[glenns]

But despite the red light indications I have (so far) never had a real (cough splutter) fuel feed problem.

Alan, what is the red light you are talking about? fuel pressure? If so you might need to adjust this slightly. I certainly had this problem when I first picked up my J160. 1/4 turn fixed the problem :big_grin:

 

 

[Alan]

Glenns,

 

I was actually referring to the red low tank indication on the two tank LED bar fuel level indicators on the dash. In turbulence on of these these can come on when you have significant (50L+) fuel remaining. My best guess is I believe:-

 

The tanks are long and thin and poorly baffled, the fuel level sender is in the wing root. When partially empty the fuel can slop away from the sender.

 

There appears to be significant damping both in the wing root gauges and even worse with the dash indications.

 

The cross flow path between the tanks seems to allow rapid fuel flow.

 

As several, with much more experience than me on this site have said before, the Jabiru J230c fuel gauges are really only a true indication when the AC is at rest on level ground! In flight the fuel gauges are at best a gross indicator (that can be distracting). I say bring back the free flowing sight gauge and watch it slop!

 

Mind you my fuel pressure warning light is also a vexed question - I will not quote what I was told by Jabiru when I was told to adjust it and I complained about its functionality. I have had the local Lame adjust this at each service and I still get a flickering light - another red light to ignore! Perhaps I need a new sender unit.

 

Alan

 

 

[glenns]

Cheers Alan,

 

I dont have that problem in my J160. It was one of the first to come out and has bubblers in the wing which are a much better system. Although they are still only useful when you are on the ground.

 

 

[jeffcb52]

Clemair,

 

Sorry I haven't looked at this page for ages. I use a Garmin 196 to provide the gps info to the JPI 450. I think any gps nmea info would work. The tricky bit is in setup. Don't select any of the gps's offered. Just select the option which you think is not going to give gps info (from memory it might be 0). Lo and behold your gps info goes into the JPI to give you fuel required to the next waypoint etc. Must admit I don't use this info as much as I thought I would. However having both fuel flow and one of the other functions available simultaneously is good.

 

I always still check my fuel "gauges" in the wing roots every half hour (have reminders set into gps setup) to make sure it all looks about right , in case there is a leak or a cap comes off.

 

Also have a float switch in the header tank connect to a red light and a loud buzzer which goes off when 2 L has gone out of header tank.

 

Hope this helps.

 

Jeff

 

 

[BigPete]

What Glenns said, and I too have a flickering fuel flow pressure light which I take as meaning I have good fuel pressure half the time. :big_grin::big_grin::big_grin:

 

regards

 

(PS - How did Jabiru tell you to fix it?)

 

 

[glenns]

Adjust the sender. They said that sometimes they need a slight adjustment. You just turn it 1/4 turn and not more light flicker. You can then test that it will come on by switching off your fuel while the engine is running and you should see the light come on pretty quickly. At a flicker first then solid after a little bit.

 

 

[BigPete]

Thankyou - will give it a try.

 

regards

 

 

[Ross]

19-J160 kit #14

 

 

 

Each of the wet wing tanks has a breather pipe going the full length of the wing and attached to the filler cap base so that theoretically it ends up in an air gap at the top outer end of the wing which is supposed to have a 1 degree dihedral. They should be just clear of the top outer inside ends of their respective tanks.

 

 

 

The inner ends exit out the top of the inner end of the tanks and are connected across the roof of the cabin with fuel hose. This connection has a T piece in it which is connected to the top of the header tank allowing any air there to return to the fuel tanks provided the small diameter hoses do not cause an air lock with the air and fuel in the line.

 

 

 

This could be a problem with a/c that have a header tank under the passenger seat making it more difficult to run a line from the tank to the overhead breather pipe with a continuous rise.

 

 

 

Ignoring the fuel vents, the connection above could also allow fuel to flow from a high wing tank to a low tank via the normal fuel supply line from the high tank then into the header tank and the header tank breather if the plane was not in balance.

 

 

 

It could also cross over via the supply lines to the bottom of the low tanks as all the normal supply points meet in a T piece before they enter the header tank.

 

 

 

There are only two brass finger screens on the bottom two connections into each wing tank so a partial or full blockage of one of these could result in fuel being drawn in down the breather tubes until they are empty if the plane is not level from the low wing tank.

 

 

 

If the plane were level with a partially blocked set of finger screens on one tank then if fitted with the glass sight gauges so fuel could come in from the top of one of those until it is drawn down below its intake level and then it would tend to come in from whichever bottom of tank inlet had the least blockage.

 

 

I noticed when assembling my fuel tank wing fittings that the finger fuel screens would end up partially covered by the long threaded fitting that they were screwed into. This could probably make it more likely to accumulate some permanent blockage over time of part of the finger screen unless they were removed periodically for cleaning.

 

 

 

I intend to pour some fuel through my tanks to try and flush any residual junk out the drain hole before they go into service. I shall have to remove the quick drain fittings to accomplish this. I have already used a vacuum cleaner to remove as much as I could from the fuel cap area and the quick drain area of the inside of each fibreglass wing tank.

 

 

 

All fuel that gets to my header tank has to go through a finger screen out of the header tank,

 

then the electric fuel pump,

 

then an inline fuel filter,

 

then the mechanical fuel pump

 

and lastly the carburettor.

 

 

 

Fuel that gets to the header tank could have got there by any of four inlets from the bottom of the tanks or from the top of either of the two sight glass fittings or possibly either of the two breather pipes in the top inner end of each tank. Only the two bottom tank lines are equipped with finger screens.

 

 

 

It appears to me that it would not matter particularly if one of the fuel-cap breathers were blocked in level balanced flight because the tank pressures should eventually balance once the fuel level was drawn down below the level of the top tank inlets and the inner ends of the breather pipes. This should then allow the fuel levels and tank pressures to equalise provided the finger screens are not blocked.

 

 

 

Fuel could flow in either direction through the finger screens.

 

 

 

Perhaps it would be sensible to do fuel flow tests on each tank from the bottom outlets if there were a problem with tanks out of kilter.

 

 

 

 

 

[jetjr]

fuel pressure light

 

I have an older J200 and was going to fit one of these but speaking to Jab I realised it was a likely waste of $$. I still might do it later on.

 

1.Jabiru only install them to plese regulatory people

 

2. You are trying to measure 10-20 kpa - very low and outside the range of nearly any transducer. Although I did find one for around $100 which would do it

 

3. If this light did come on for real you have only the fuel left in the carb to go - ie seconds

 

4 Jab suggested they had never seen one of the mechanical pumps fail

 

5. the light in the header tank would be much more useful in a low fuel situation

 

Apparantly there are regular complaints (and stressful owners) with these lights.

 

JR

 

 

[Guest stephen]

Fuel flow meter

 

I have a JPI 450 fitted to a J200 and it works quite well. Very easy to calibrate and as an added precaution, I still check the fuel sight glass periodically when flying in case of accidental fuel loss through venting or leaking pipe. (Hasnt happened but I dont rely entirely on electronics if I dont have to.) I did have a problem with the JPI when I first got it and sent it back for replacement after it randomly kept resetting itself in flight. I have been using it for 2 years now with no problems. It fitted nicely in the dash hole left from when the original radio (supplied by Jabiru) continually caused problems and died. (replaced with a Garmin and works much better)

 

Steve