Mr. Slade still taking arrows being out front...thanks (clogged fuel filter)

[CBarber]

I tried posting this to the FlyRotary list too, but cannot get the pictures to post, so I am cross posting here with the picturs.

 

Even though this issue is with my rotary powered Velocity, it applies to all engines, espcially those with composite fuel tanks....and those that have had to rebuild 'ema....like John Slade and I.

 

I went out to the hangar after my duty shift of "protecting and serving" was over, as I try to do most nights. It is amazing how productive I can be not getting there until about 11:30pm when there is not one to interrupt. I concede, I like the interruptions, at times, when I am out there during the day, but, they are still interruptions <g>.

 

Anyway, after doing some dry installs of my glare shield over my IP I decided to push the bird out on the ramp and start her up. I am doing much better, but am having some continued intermedant issues with my electrics. It may just be down to some bad crimps on some switches. Donno yet, but I do seem to have my charging issues on my duel alt/duel bat Z-14 Aeroelectric set-up do ok since I got one of the regulators back from B&C after them repairing it.

 

For those of you keeping up, yes, I am cranking/running my really loud airplane up well after 11:30 pm. Sometimes around 1:00am or so. My hangar is WELL away from residences and even at this late hour military and corp jets come and go at EFD (Ellington) at all times. So, I decided to see what "issues" I could discover tonight and try to find a cause for. The intermedet electrical issues are getting better, but still persist. SIGH.

 

Soooo, I cranked it up. It started clean and strong. I improves several wire runs, switches to lights etc and tested everything with the new regulator and things were mostly good. (still a couple of inconsistencies, but improving). It is kinda fun to turn on my landing lights, nave lights, strobes, interior lights, and light strip in the glare shield.

 

It plane was idling well and the temps were holding well. I am trying to idle around 1500 ish rpm in order to keep the Oil Pressure above 35 (the EM2 default). I can go lower but the warning light starts ot flash annoyingly (usually I prefer to wait until the oil temp raises. It does not do so near idle, but if I give her the gas, the oil raises pretty quick).

 

Ok, enough background. I give her the gas to see what happens......BOG, near stall, pulled back on the throttle, still running rough as hell...hey, I just taxied around and it was fine, but now, it will not smooth out. Shut down, restart, same thing. Crap.

 

Hmmmm, John Slades cautionary tale, in which he even mentioned me by name <g> came to mind. I pushed the beast back in the hangar and decided to check the first fuel filter. The symptoms really did seem like a fuel issue. The first inline filter past the sump come off fast and is easy to get to with the lower cowl off. Pulled it off, looked through it....looked good.....shook it....uh oh. a big chunk of something fell from the side. I got two one inches wrenches and unscrewed the filter and a chunk of tank debris fell out. Lots of residue on the side of the housing and in the screen. Took these pix for ya'll's considered amusement <g>.

 

Cleaned it all up, reinstalled. Fired her up again and ran great for a few minutes...until I added power. Then the same thing. Pushed her back in....removed the filter and it was clogged again.....not as bad this time though. So, this time I added several gallons of fuel, disconnected the line to the injectors and secondary filter and ran the pumps for a few minutes (the bog was worse on the secondary pump). Before all the fuel that was being pumped into a gas can was exhausted I killed the pumps. I did notice both pumps were putting out what seemed to be about the same amount when run individually and a stronger stream when they were both on. Even though I know it is impossible to know it was better just by looking at the streams, I put it all back together and cranked it up again and it ran great. After playing a bit, I pushed back into the hangar and dropped the filter again and this time it was still clean.

 

All in all, not a bad night. Please forgive the quality of these pix as they are taken on my phone....a phone that actually works as a PHONE better than it does other stuff...like pictures <g>...well, it does text great. The pix should give you an idea though. You can see the chunk of debris in the foreground. Thanks.

 

Enjoy.

 

All the best,

 

Chris Barber

Houston

[David Clifford]

Chris. I don't know if you read the other forums but you may want to check this thread post #15. Just a finer screen in the filter caused all kinds of problems. http://forum.canardaviation.com/showthread.php?p=56540#post56540

[argoldman]

Don't know if I posted this here. If I did, forgive me. If not, consider the idea.

 

These filters do clog up while doing the job they are supposed to do. It is vital, therefore to eliminate as much crap from the tanks created by the construction technique as possible.

 

There are two issues here, the crap that floats and the crap that sinks.

 

What I did with my dragonfly, and will do with my Aerocanard was to go through a process of tank purges wherein I connected a facet pump to the output of the tank, plumbed it through a large automotive filter then through a fuel injection filter then back into the fuel tank. I allowed this to reflux for several hours, filling the tank initially with only a couple of gallons, periodically shaking the wing, letting it reflux and draining it completely (through the pump/filter mechanism) after the reflux activity (to get rid of as much of the floaters as possible). I then incrementally increased the amount of fuel that I put in and repeated the process. At each iteration I examined the filters and cleaned/replaced them as necessary. The last one, I filled the tank completely, went through the reflux and shaking process and drained the tank completely .

 

Repeat on other wing!!!

 

Warning-- Don't smoke here or do this in a closed hanger.

[ErlendM]

Warning-- Don't smoke here or do this in a closed hanger.

I like this approach and will most certainly do the same when my plane is ready. I just wonder - why use fuel here, will using water instead give any problem? I realize I have to get rid of the water completely, but that should not be too hard.

[argoldman]

I like this approach and will most certainly do the same when my plane is ready. I just wonder - why use fuel here, will using water instead give any problem? I realize I have to get rid of the water completely, but that should not be too hard.

 

Ya, I left that part out, however, I wonder, if there isn't a benefit of the solubility factor of the gasoline. Perhaps a final rinse?

[David Clifford]

I like Rich's idea of using pumps to flush the tanks. Wish we had thought of that. We instead did it manualy filtering the gas through a filtered funnel into 5 gallon tanks. We did 20 gallons per side each flush and did each side probably 20 times until we did not capture any more junk in the filter. It was a messy stinky job! I don't think I would want to introduce water for a flush but it probably would work fine provided you did several final flush's with fuel. We did not expect to find any construction debris in the fuel filter, but at the condition inspection, did find some trapped in the screen. But what was in the filter screen did not effect fuel pressure. It was not until the new screen was installed did pressure problems develope.

[argoldman]

I like Rich's idea of using pumps to flush the tanks. Wish we had thought of that. We instead did it manualy filtering the gas through a filtered funnel into 5 gallon tanks. We did 20 gallons per side each flush and did each side probably 20 times until we did not capture any more junk in the filter. It was a messy stinky job! I don't think I would want to introduce water for a flush but it probably would work fine provided you did several final flush's with fuel. We did not expect to find any construction debris in the fuel filter, but at the condition inspection, did find some trapped in the screen. But what was in the filter screen did not effect fuel pressure. It was not until the new screen was installed did pressure problems develope.

Dave,

 

Shaking the wing while this is going on, I think, is an important part of the equation.

 

Now, the fact that the new pressure problem happened with the new filter is important in that the job of a filter is to keep stuff out of things that are critical. If your original filter was passing these things, worse things can be plugged. I would certainly check downstream of the filter for grunge. If you use multiple filters of decreasing hole size, ultimately you will get the pluggage problem, although it will be over a longer period of time and give you the opportunity to clean the multiple filters to prevent stoppage.

 

In the Aerocanard kit strakes, you put the fuel fillers in before assembling the top of the strake on the rest, thus eliminating the problem of introducing cutting dust into the fuel tanks.

 

If you do have to cut into the strake for the filler, or other reasons, slightly presurize the strake (careful) at the forward drain area so that dust created by cutting will be blown out of the kerf, rather than dropping into the tank. You can also use a vacuum on top where you are cutting, or better yet, Both!

[Waiter]

Use a fine mesh brass screen (the kind they use on water well heads to filter out sand) over the sump hole.

 

Vacuum out the strakes, Use a 3/4 garden hose duct taped to the vacuum, To get into the smaller areas, I used a 3/8 aluminum tube about 2 ft long taped to the 3/4 garden hose.

 

Waiter

[TMann]

I believe Wayne had a tip for cutting the openings for the filler cap assembly. I would have to check for accuracy but I believe he used a soldering iron to make the cut thus eliminating any dust and particulates.

[Bruce]

Not sure if it was Wayne who did this, but, someone used a two step cutting process for cutting the openings. Cut the top layer of glass, remove the foam, vacuum, then cut the bottom layer of glass. This would certainly help cut down on the amount of debris going inside the tank.

[Wayne Hicks]

Wayne here. I haven't cut my fuel cap openings yet. But the trick is to do what yall are saying. Cut and remove outer skin, remove the foam, them cut the inside skin loose. I suggested it can be cut with a soldering iron configured with a hot knife blade. A heated exacto knife blade will do the same.

[Waiter]

Cut the outer skin and do as much of the foam work as you can.

 

When your ready to cut the inner skin, I used a hole saw, and just kept a vacuum claeaner on it to get as much debris as I could.

 

Then vcuum out the strakes with the small hoses.

 

 

 

Waiter

[David Clifford]

Dave,

 

Shaking the wing while this is going on, I think, is an important part of the equation.

 

Now, the fact that the new pressure problem happened with the new filter is important in that the job of a filter is to keep stuff out of things that are critical. If your original filter was passing these things, worse things can be plugged. I would certainly check downstream of the filter for grunge. If you use multiple filters of decreasing hole size, ultimately you will get the pluggage problem, although it will be over a longer period of time and give you the opportunity to clean the multiple filters to prevent stoppage.

 

In the Aerocanard kit strakes, you put the fuel fillers in before assembling the top of the strake on the rest, thus eliminating the problem of introducing cutting dust into the fuel tanks.

 

If you do have to cut into the strake for the filler, or other reasons, slightly presurize the strake (careful) at the forward drain area so that dust created by cutting will be blown out of the kerf, rather than dropping into the tank. You can also use a vacuum on top where you are cutting, or better yet, Both!

Yaeh...we shook the wings while flushing. The problem with the new filter screen was the mesh was too fine, or defective . That alone was enough to lower the fuel pressure with the mechanical fuel pump enough to cause a significant loss of power and roughness. There were no obstructions from debris, just the fine screen micron rating caused the restriction. Switching back to the original screen after we cleaned it fixed it. As a test, I disconnected the fuel line at the pump and let the fuel flow by gravity. It was a slow flow with the new screen and a nice steady stream with the old screen. I purchased the "RV Special" package from the Andair booth at Osh that included their valve, pump, filter, and installation package. I hope I don't have any of these problems.

[argoldman]

Another thought came to me as I was getting ready to leave my office.

 

On which side of the pump have you placed your filter.

 

Most pumps push better than they pull. Is your filter, by any chance, between the tank and the pump??

[Jerry Schneider]

I used water. But I offer this one caveat:

Make sure you don't let a lot of time pass before you add fuel, as I did.(MONTHS).

When I finally got around to adding fuel, when checking the forward fuel drains, they were severely corroded, and the one I checked wouldn't spring shut. Thereby squirting copious amounts of fuel all over me and the hangar floor. I IMMEDIATELY stubbed out my cigarette, ( don't smoke), and darted furtively around the shop looking for an appropriate plug.

 

If I had it to do over, I'd use fuel.... stinky mess or not. I STILL have a sneaking suspicion there's a pretty good slug of water lurking somewhere in there.

 

Buyer Beware!

 

(Wayne: No! I didn't check the other side 'till I had a replacement in my hand. Thought about it though..... )

[David Clifford]

Another thought came to me as I was getting ready to leave my office.

 

On which side of the pump have you placed your filter.

 

Most pumps push better than they pull. Is your filter, by any chance, between the tank and the pump??

Filter is pre-pump per mfg directions. Apparently these HP fuel injection pumps can be easily trashed by debris. Same scenario with my Andair set up. The Andair filter screws right into the IN side of the pump.

[rickh]

<hijack>

 

1) www.smalparts.com has quite a selection of 'stuff', including various mesh screens for the strake -> sump.

 

2) Is there a consensus to the mesh size? Cozy plans say "from the hardware store...". I know it shouldn't be to small/fine/close, nor 1" chicken wire.

 

3) Thanks for the tip on the sump valve Jerry.

</ hijack>

 

Rick

[mfryer]

<hijack>

 

1) www.smalparts.com has quite a selection of 'stuff', including various mesh screens for the strake -> sump.

 

Rick

Did you mean www.smallparts.com?

[mfryer]

oops duplicate post.

[argoldman]

Filter is pre-pump per mfg directions. Apparently these HP fuel injection pumps can be easily trashed by debris. Same scenario with my Andair set up. The Andair filter screws right into the IN side of the pump.

 

Which begs the question, "What size of particle is detrimental to the pump and might a coarser filter before the pump and a finer one after do well? Is that Andair part aviation or other??

[rickh]

Ma touch typing skills aren't what they used to be, are they? (like they ever were)

 

Rick

[TMann]

Is that Andair part aviation or other??

Andair is aviation

[Phil Kriley]

[quote name=rickh

2) Is there a consensus to the mesh size? Cozy plans say "from the hardware store...". I know it shouldn't be to small/fine/close' date=' nor 1" chicken wire.

 

Rick[/quote]

 

If the hardware store screen corrodes, as Jerry indicates, is there a copper or brass or stainless screen that might be a better choice?

[Richard Schubert]

I have heard of people using stainless steel tea strainers

 

http://www.englishteastore.com/teastrainers.html

 

Take a quick trip to Bed/Bath/Beyond, they have several sizes.

[Waiter]

The stuff I used was very fine, I want to say 40 weaves per inch (I think).

 

It covers the entire corner of the strake, I would say 4inches by 4 inches, and its at a slant. The slant allows it to self clean.

 

You can also see it (well, before I installed the retracts) through the fuel cap. Prior to refueling, take a look at the screen, then when you refuel, point the fuel nozzel at the screen to wash it off.

 

Heres a photo of the screen. You can see more strake photos on my web site;

 

http://www.iflyez.com/LongEZ_Construction_Photos_Strake.shtml

 

This is a brass screen that is used on shallow water well pickups to keep out sand. Check McMaster-Carr.

 

Waiter