Shane,
Sounds like ethanol my be the culprit to me. just a thought.
Shane,
Sounds like ethanol my be the culprit to me. just a thought.
Flying a series 4 speedster
Rotax 912uls whirlwind 75”
I removed my poly header tank tonight and even though it was half full, no fuel came out when I removed all the lines. It has been setting for ten years and all the fittings were plugged solid. That made the tank removal very easy, but I was surprised how much the Mil-6000 hoses had degraded and came apart inside. So now after reading this thread, I don't know what hoses to buy as replacements.
Slightly off topic now but it seems to me that, if you intend to run auto fuel then automotive fuel lines would be a good choice. I replaced my Mil-6000 hoses with automotive fuel lines when I started smelling fuel in the cabin about five years ago. I don't believe that my current problem is related to the fuel lines degrading but rather the fuel itself went bad. I'm personaly leaning towards an all metal solution now (except for those parts that need to flex for wing folding of course). I have no experience with metal fuel lines but it seems like it shouldn't be too difficult...
PropellerHead,
Your idea is precisely what I followed....since autogas was my fuel of choice, hoses, etc seemed the best bet - afterall, cars have been using SAE hoses and autogas for a while - I never installed the milspec hoses.
If you are looking for some guidance on fabricating metal lines.....there is a huge library of on line videos on the EAA website titled "Tips for homebuilders" I believe metal tubing fabrication for fuel lines is out there. Lots of other good stuff too.
The biggest issues with metal fuel lines is bending, including the correct radius; and, most of all, forming the flanges for the 37 degree fittings - takes a bit of practice and a bad one can crack under the fitting. Practice makes perfect.
Sincerely,
Dave S
KF 7 Trigear
912ULS Warp Drive
Dave and Luis,
The biggest problem with all metal fuel lines is metal fatigue due to vibration. Do a search on "work hardening". Personally, I wouldn't do it. You really need flex points - particularly before of after bends, hard connections to different parts of the structure, before and after bulkhead through fittings (firewall) and connections to the biggest vibrator of all - the engine. Not to mention the additional fabrication work to make something that will eventually fail over time, if not totally isolated from all vibration.
Good Luck, Greg
Hmm. Sounds like good reason to do the opposite and replace all my lines with automotive fuel line. Especially if it's something that has a high possibility of breaking early because I did it wrong.
I suppose you could, but then you need to be careful with attach points and thru bulkhead fittings (firewall) as the vibrations at those points can cause chafing and wear on non-metallic piping. There are good reasons for seeing both used on fuel systems of all machines, not just aircraft.
Greg