Lancair Live!

Hello community:
I want to be able to use mogas on my plane. I plan to use a UL 520 iST engine. LOTS of questions...

I understand mogas with ethanol will cause delamination on the tanks if they're not properly sealed. What's the recommended ethanol resistant sealant?
The UL 520 iST is turbocharged, I assume less tolerant to leaning. Therefore I would like to have 52-54 gals fuel. There are several options:
I have the header tank (10 gal). I have the outboard wing tanks (15 gals ea). I've seen 360's that have the middle wing section used as a 17 gal tank per side.
I can open and seal that middle section, good for 34 gals, and use the outboard tanks as 5 gals/side. I am also installing the extended wing tips.
And to top the confusion, I've read that sometimes the whole leading edge can/has been used as a gas tank.

Not wanting to reinvent the wheel, taking all advise seriously, hoping some Forum members have more info of what I could find (very little actually).

Jose Santos

Jose, that sounds like a big project. I've heard good things about the UL engines, but it'll be a one-off for your LNC2. You are correct about the 360s having 17 gal per side. Hopefully someone else knows about stuffing more fuel into the plane. Be advised, even with the 60 lb weight saving the UL provides, if you go over the 17 gal/side, you'll be eating into your useful load.

Also, do you know if the engine will fit the stock cowling with the mounting position farther forward than the Lycoming mount? I assume you'll need to move it forward for CG?

Keep us posted on your project!

Hello;
There is a LN 360 at my airport (KAEG) that has the 17 gal/side inner wing tanks. I built mine with the 15 gal/side outer section. I'm thinking that the 17 gal/side will add 2 gal/side with the possibility of having space to add another 5 gals on the outer sections as the mission requires. However, I want to have all the info about the ethanol resistant tank sealant before reinventing the wheel and opening up my wings. Will try to post pics.

If my recall doesn't fail me I read some time ago one of our Aeronautical Engineer forum members did some calculations of the UL 520 iST on a LN... numbers were somewhere in the vicinity of 250 kts at 15,000 ft. That is what made me give the UL 520 serious consideration. The downside is the mandatory O2 tank and the estimated 10 gal/hr fuel burn.