Diesel Fuel Caps

[Archer39J]

For those of us who are eyeing diesel engines for our Bearhawks. I was reading chapter 14 of the aviation maintenance technician handbook for airframes and came across this on page 14-59:

"Note that an over-the-wing refueling nozzle for turbine engine fuel should be too large to fit into the fill opening on an aircraft utilizing gasoline."

I've never fueled with Jet-A or even seen a Jet-A nozzle but it sounds like they're sized differently to avgas? Will the stock avipro caps still work for my application?

[Chris In Milwaukee]

Probably not. A Jet-A nozzle is pretty humongous:

[Archer39J]

Oh man, now I'm into modifying the tanks too. Great...

Final engine selection is some time away, and installing the engine will be the last thing I do, so since the tanks are removable and everything is pretty open I figure I can build on for some time before making any cuts to solve this. Good thing I happened to come across this, thanks for the pic

[Chris In Milwaukee]

Big funnels are pretty cheap

[Archer39J]

I guess, but easy identification is one reason for the size difference, if one wanted to be " proper". Haven't found anything on cap sizes for experiential diesels yet though, still looking.

[marcusofcotton]

2.7" nozzle. It would be messy and difficult holding a heavy jet a nozzle over a funnel while carefully restricting flow.

[Archer39J]

This was my thought as well.

[Chris In Milwaukee]

I guess I should have used the SmartyPants font when I typed that 😇

[Archer39J]

Oh, lol, gotcha. Well it at least sounded somewhat plausible to me

[whee]

It would be really easy to have someone make a set of caps of the BH design but upsized for Jet-A. Cutting off the smaller neck and welding on a bigger one is another easy job.

[Archer39J]

It would be really easy to have someone make a set of caps of the BH design but upsized for Jet-A. Cutting off the smaller neck and welding on a bigger one is another easy job.

Define easy...

Haha, yeah you're right though it's not the worst thing in the world. Though I'll probably outsource it should I go that route. It's possible I could fab the caps myself though, that would be fun...

[Chris In Milwaukee]

The thing I don’t know, because I haven’t spent a lot of time around turbines, is if the fuel tank hole is round - but bigger - or if it’s oblong like the nozzle. Probably a silly thing to say, though. I couldn’t imagine a weird shaped fuel cap like that.

[whee]

Define easy...

Haha, yeah you're right though it's not the worst thing in the world. Though I'll probably outsource it should I go that route. It's possible I could fab the caps myself though, that would be fun...

LOL. $100 bucks to my buddy with a machine shop to make the caps and $20 to the weld shop I use when I don't want to do it myself.

[Archer39J]

The thing I don’t know, because I haven’t spent a lot of time around turbines, is if the fuel tank hole is round - but bigger - or if it’s oblong like the nozzle. Probably a silly thing to say, though. I couldn’t imagine a weird shaped fuel cap like that.

Well something to determine for sure, next time I'm out at the hangar I'll see if I can't take a look at something that burns Jet-A. Would be real odd if they weren't round though, PITA design that'd be for sure...

LOL. $100 bucks to my buddy with a machine shop to make the caps and $20 to the weld shop I use when I don't want to do it myself.

Having access to shop equipment at work would be my only bet on the caps, but as much as I'd like to get into welding I'd rather not learn on my fuel tanks lol.

[Rollie]

They still use round gas caps, in a round filler hole. Its just bigger. like 3.5 to 4 inch. I never quite got why they like that oblong nozzle. Now and then you find an FBO with a big round nozzle. Either way the Jet A comes out pretty fast as most things that use it are going to hold quite a bit more than our 27.5 gallon tanks. Easy to overflow and make a big mess, and it doesn't just evaporate away like av-gas.

But if you really want to have fun modifying the fuel system, you could go with single point pressure refueling. That would give you the dual bonus of costing a lot and adding extra weight.

Good luck on the diesel install though, That should be impressive.

[Archer39J]

IF it comes to fruition, plenty of false starts and broken promises along the diesel path before...

[MattS]

Archer39J in your opinion, as of right now, which diesel would be in "first place" for the Bearhawk? I know there is a mission in Africa using the Cessna 182 with a diesel with success (from what I've heard through the grapevine).

[Mark Goldberg]

There is a diesel engine manufacturer in the U.K. that is working on a firewall forward package for the 4 place BH. It is very early to know whether their efforts will produce something good. But there are a couple guys interested in their engines, and we will see how it goes. Mark

[Archer39J]

Archer39J in your opinion, as of right now, which diesel would be in "first place" for the Bearhawk? I know there is a mission in Africa using the Cessna 182 with a diesel with success (from what I've heard through the grapevine).

Oh I'm not even remotely qualified to answer that, but to my knowledge right now there isn't one. Still very early in the planning stage...