My latest project MK4

[RobS 52]

Doug and Joey thanks for the info - looks like one more thing for me to consider. 

One general question about the original Avid fiberglass tanks. In general, how do they hold up if you use 100LL or mogas with no ethanol? I have access to ethanol-free mogas at two airports close to me and I'd pay about a $1.00/gallon premium for it over gas with ethanol, but this stuff is guaranteed free of corn mash! 

[EDMO 1078]

Doug and Joey thanks for the info - looks like one more thing for me to consider. 

One general question about the original Avid fiberglass tanks. In general, how do they hold up if you use 100LL or mogas with no ethanol? I have access to ethanol-free mogas at two airports close to me and I'd pay about a $1.00/gallon premium for it over gas with ethanol, but this stuff is guaranteed free of corn mash! 

Supposedly, if you believe your government, the gas sold at the airports is tested - but sometimes it is a private vendor selling it.   Seems like some of our members have been using the fg tanks for years.   Mine never failed, but others did. 

There is a tester that you can buy, but I have never used one or seen it used.   I buy E-Free Mogas at MFA station that sells tractor gas for farmers.   EDMO

Edited 1 Nov 2016 by EDMO

[1avidflyer 1983]

One way to test for alcohol in the fuel is put some in a small clear bottle.  Pill bottle or spice bottle maybe.  Add a few drops of food coloring.  (borrowed from the kitchen) Shake the bottle.  If there is alcohol in the fuel, the gas will change color and the coloring will dissolve into the mix.  If no alcohol, the food coloring will reform in drops at the bottom of the bottle if you leave it sit for just a little bit.  JImChuk

[dholly 718]

@Rob - Well I suppose any old tank can fail anytime, but I've seen very few problems with the old polyester resin wing tanks leaking when using e-free. Personally, I'd just pay the extra $1/gal or schlep my own e-free vs. the time and expense of replacing both wing tanks. Bottom line is the poly options are limited and less than perfect. The new f/g tanks are sold as e-resistant not e-proof, and who know what gas additives might come down the pike in the foreseeable future that could effect the current vinylester resin. Both paths have some compromises, certainly neither are cheap and the payback period is just too long if you have e-free readily available, IMHO. I know many folks who believe that even 100LL + Decalin is cost effective given how many hrs they fly, although they also tend to place value on the reduction of vapor lock potential. If you go on XC's, just take a little Decalin with you.

[RobS 52]

Doug - you're thoughts pretty much align with what I've been thinking. If I were going to change the tanks, now would be the time as I haven't started to cover the wings. But then I think of the cost, time, and PITA that would be versus the benefit and I'm not sure it's worth it. Seems like others have had good experience with the original Avid tanks holding up (if you go E-free), so I'm going to stick with the original tanks as the first owner of my kit did a really good job of installing them.

Thanks again to this group - it's really good to be able to hear from others on the thoughts that are bouncing around in my head! 

[C5Engineer 1170]

Joey - I can't remember if you mentioned it and I can't count the # of ribs or nose ribs in the pics. Are the 'factory built' extended speed wings built to 18" o.c. S.T.O.L. or 12" o.c. H.H. spec? How many nose ribs between ribs? Do you know if they have factory (1-1/2", IIRC) twist or less? Interesting D.I.Y. f/g root ribs.

Doug there are 2 ribs between each flaperon hanger rib and two nose ribs between every rib. Could not find any info from the factory on the washout. The Fiberglass root rib exists on the right side because it was the only wing that had a tank in it. The other side was done with aluminum.

Stace up in Idaho is still selling the Poly tanks. When I do I true capacity test on the fuel system I will find out about how fast or slow they transfer from the outboard to the inboard side. One thing that I am concerned about it mixing my oil when on the road with this set up. On my other one I just put a known quantity in the tank and poured in the oil in afterwards and then sloshed it around with the strut. Not sure if that's going to work with this set up. When I'm at at the hangar I just pre-mix it in a jug and pour it in. That's not going to work at the pump. 

Edited 2 Nov 2016 by C5Engineer

[Av8r3400 1178]

Easy solution, Joey.  

Rotax 912 with one of Leni's spiffy mounts.

[akflyer 1427]

Or carry a jug with you, premix, dump in tank, mix, dump.. or put the damn oil injection back on it and don't worry about it

 

[TJay 1041]

oil injection gets my vote on all 2 strokes,

[C5Engineer 1170]

Easy solution, Joey.  

Rotax 912 with one of Leni's spiffy mounts.

If only it were that e$sy.

Tjay I've ran premix in every dirt bike, sno mo, leaf blower, weed whacker I've owned for years and years. Hard to change and after doing my repairmans course and seeing Brian Carpenters box of failed oil injection pumps I don't trust em. I have it on the powered parachute I'm running and I think it needs to go too.

[C5Engineer 1170]

Pulled em both out of the hangar today. Super cool firing up the new one with the clutch. 

[C5Engineer 1170]

Sorry for the lack of info on this bird. With the holidays upon us it's not gotten the attention it deserves. Anyone building submit your paperwork now as the FAA is WAY behind!!! 

[C5Engineer 1170]

Wow I can't believe this thread is over a year old!! I suppose most of you gave up on me with this project. I ended up changing quite a few things on this airplane which ate up a lot of time. Couple that with being gone most of the summer for work and yet another deployment and well here we are a year later. I hope to keep updating this thread as I go through the inspection process and get it going into Phase 1 testing.