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Filters, again.
Posted: Thu Jun 28, 2007 11:53 pm
by Mogas
Ok John and Boet
So I am really bored and I will take the bait. BYO biltong and beer!
Lets talk about the filters again.
A long long time ago I had my first engine out.
You guessed it, blocked filter. But the one I was using was one of those plastic jobs. I also used to use that high pressure black fuel hose but was okey cause I used to change both regularly.
Then one day a large flake of paint found its way into my fuel system, still dunno how but it did. Murphy made sure it lodged itself right at the intake side of the single non seethru filter, without even getting to the paper.
Not even my electric fuel pump would move it along and me and the mopane trees got well aquainted after a short glide.
Lessons I learned from that were: 1. Do whatever you can to see what goes on INSIDE your fuel system. 2. Do whatever you can to put CLEAN fuel into your tank and ensure it stays that way.
I am sure the non believers have very good reasons for not liking these filters. I respect that. But I also think I have good reasons to like them. Thought I would post this as someone may learn something from it. If it is that ridiculous, tell the thought police and have them remove it.
Posted: Fri Jun 29, 2007 5:49 am
by KFA
Hi Rick, I think you must also add that your setup has one filter for each carb so the flo through each filter is halve of what the other guys with engine outs had.

Posted: Fri Jun 29, 2007 6:03 am
by Duck Rogers
KFA wrote:Hi Rick, I think you must also add that your setup has one filter for each carb so the flo through each filter is halve of what the other guys with engine outs had.

So does that mean only half the "thickness" of the fuel passes through the so called "too fine mesh"?
Oh shucks, I got tempted

Posted: Fri Jun 29, 2007 8:29 am
by Mogas
:D Ha ha Duck. Got your dose of clever pills this morning then?
Posted: Fri Jun 29, 2007 8:43 am
by Aerosan
Posted: Fri Jun 29, 2007 9:22 am
by Morph
where can one get the blue fuel line? I was thinking of only putting it between the tap above the door and the header tank so you can see if there is fuel flow.
The rest of the fuel system is under covers etc so I don't see any value in a completely transparent system.
BTW I am a bit suspicious about this line. One of my mates ith a BB had a problem with the piece going from the tap to the tank. Overnight it ruptured and the next day the entire cockpit was soaked in fuel. Not a good thing. On replacement we found the entire line to be brittle.
GR8-Dad and I collected his BB from Loeries after he had some work done on it. After the 1 hour flight we landed at Nooitgedacght and I noticed some liquid dripping out of the bottom of the engine bay. We opened up and the fuel was leaking from a split in the brand new blue line directly onto the very hot exhaust.
BTW I was actually thinking of putting a filter on each tank just next to the taps or just before it goes into the header tank. I am not that keen on a filter per bank of pistons as a blockage in one will leave the engine only running on two pistons. This way if one of the filters blocks I still have 5 liters in the header plus the other fuel tank, hopefully not empty, to run on. The only negative of this is having replaceable fuel filters in the cockpit and close to the lexan which can and will leave marks and crack if fuel drips on it.
Posted: Fri Jun 29, 2007 9:50 am
by DarkHelmet
The new filter supplied by aviation engines is transparant!
Apparantly Benz altered the mesh on the diesel one!
Posted: Fri Jun 29, 2007 10:09 am
by Morph
Second question Mogas. It appears that your filters are after the mechanical fuel pump. DO you have one before protecting the pump from grit damaging/jamming the diaphram
Lastly, I do passionatly hate those filters. There are far to many bad stories including my own to just ignore. They go from unblocked to completely blocked in 5 minutes.
Posted: Fri Jun 29, 2007 4:47 pm
by Mogas
Morph, the "blue line" I use came from California power systems, try google 1-800-airwolf. I bought 100 feet of the stuff years ago. I suspect the other "blue line" referred to is something else.
Good idea to put a filter each side upstream of the header tank, need not be anywhere near the lexan, I would securely fit them below the dash not near any looms but in easy sight, I may just do that myself and have those in addition to my present ones. and they will be the preflightable glass ones as well

Posted: Fri Jun 29, 2007 8:07 pm
by KFA
Posted: Fri Jun 29, 2007 9:05 pm
by Morph
KFA wrote:Remember that if you have a filter in the cockpit area you will always spill fuel in the cabin when cleaning them. The same for after the taps setup.
Too true, my only concern, but this is a manageable one, make sure you close the tap, use a rag and replace the filter. If you get a nice see-through one you can constantly monitor it, but not one of them glass ones as in Mogas' avitar.

Posted: Fri Jun 29, 2007 9:44 pm
by Mogas
I also filter my fuel when going into my tank as KFA says.
My so called super fine mesh filters are NEVER dirty.
Due to the fact that I give them a visual every day, I do not strip them often. The other day my hundred hour service was due so I thought I would strip my clean filters for the first time. Before I pulled them off I disconnected at the carb then turned on the tap to check the flow...........It was as if there was no filter installed, fuel poured out.
Like I said, check them every day, filter your fuel when you put it in and you will have no problems. If you are not prepared to do this you will have to go the plastic route.
Posted: Sat Jun 30, 2007 8:46 am
by Duck Rogers
Posted: Sat Jun 30, 2007 2:03 pm
by Boet
There will be as many different fuel systems as there is homebuilt planes, it seems. :D
THE "BLUE PIPE". Do NOT use it if there is nothing written in white letters on the pipe. The blue pipe with no writing on it is bogus.
Black rubber "petrol pipe"........

SAY NO MORE.
Posted: Thu Jul 05, 2007 1:45 pm
by Biggles
Just bought 5 Benz filters for 21 rond each. I asked about the the transparent ones and the guy said that was another manufacturer that they don't use anymore. But the new ones I just got are translucent, so while you cannot see any grit in the thing you can still see if theres fuel in. The one I replaced is completely opaque.
The mesh size is the same at 0.3 (mm I presume).