One of the things that I found during my flyoff hours that I
wasn't so happy about were the fuel caps that are part of the
RV-14 kit. It isn't really the design of the caps that was
the issue, but more the material they were made out of.
The fuel caps that are provided with the RV-14 kit are the SPRL
fuel caps, made of plastic, by Newton.
They make them in both standard and lockable versions, but when
I contacted them, they only offer them in plastic.
When I was in process of building I wasn't sure what I wanted
to do with them. The grey plastic color isn't the most
appealing, and anything made of plastic like that kind of
"cheapens" the image of it also. Additionally I wanted
engraved fuel caps, like
I did on my RV-10. The Engraving not only identifies the
caps as yours, and if you lose them, gives the finder a way to
get them back to you via your N-Number registration, but it
helps you comply with the markings you should have by your fuel
tank openings. In the case of the RV-14 that would be
100LL only, 25 U.S. Gallons per tank. So even while
building the wings, I wasn't completely satisfied with the fuel
caps that were included.
Then it came time to fly. Within the first few flights, I
had been flying on some windy days with winds in the 15-20kt
range, and when I went to fuel up I would do my usual routine of
removing the caps, placing them on the wing walk, fueling, and
then replacing them. The problem was, the caps were so
light (which would normally be a good thing), that they blew
right off the wings on 2 separate occasions. So I called
Newton to see if they offered an Aluminum version and they said
"no", and offered that maybe I should put the fuel caps in my
pocket while fueling. Yeah, right.
The final straw came when I was out doing some rolls, and even
though I was maybe 3000' above my house, my family caught a
video of me and while upside down I had 2 large fans of fuel
streaming out from the fuel caps! They sent me a text
message and so I went and did some more rolls and sure enough,
every time I went inverted, with the fuel pushing to the outside
of the tanks due to centripetal force, I had a fair amount of
fuel spraying out. No wonder I had been getting blue
stains down by my flaps!
Now the leakage wasn't the fault of it being plastic, because
just by disassembling the cap and lubing the o-ring, and then
tightening the nut a little on the fuel cap stem a little extra,
I was able to reduce or prevent the fuel leakage. But
while disassembling the fuel cap I decided I would set out on a
mission to have some aluminum ones machined.
I talked to Geoff Combs, from Aerosport
Products, during OSH 2016 about the issue, because he's
made many very nice products for RV's from both Aluminum, and
Carbon Fiber, and does a very good job with everything they
do. I had already purchased a new fuel cap and ring to use
to measure out for machining a replacement top, so I sent it to
him for him to use. Eventually he sent me a photo of one
he had made out of a plastic compound, more as a proof of
design, and it was great!
Then he got to work on doing them out of aluminum. The result is shown below. I now have a fantastic set of aluminum fuel cap tops for my RV-14!
Here are some things to make note of:
1) You can get just the aluminum top, at least this is how it
is as of this writing. You will re-use your original
o-rings, springs, washers, nuts, stem, locking base, and flip
tab. It's an exact fit for all of the parts.