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Fuel Caps - Any better?

TimO

Well Known Member
I'm thinking I may need to get some better fuel caps than the ones that came with the RV-14 Kit. Does anyone know if they're standard enough that I can buy a set elsewhere? I tried my spare RV-10 caps in them but they are smaller than the RV-14 fuel caps.

The reasons are twofold:

1) a couple times now when I've been fueling, I set the caps on the wing walk area, and the wind has blown them off the plane and back by the tail on the ground. They're just so light, which is sometimes a good thing, but in this case, if it's happened twice already in just over a week, it's going to be a long-term pain.

2) Today when I was doing a few rolls near my house (I live in a barren area), the kid and wife looked up and texted me that I was leaking fuel from both wings. I decided to look sideways on the next roll and sure enough, both fuel caps were just pouring out a fan of fuel while I was upside down. And, I wasn't at all negative when it happened (although the tanks were prob. at least 3/4 full).

Maybe I can change out the seals to larger o-rings or something and fix #2, but considering I'm not already that keen on these plastic fuel caps, if there is a source for good aluminum ones that fit, I'll probably just have some engraved ones made and replace these and keep it as a spare. Being light plastic, it would be a nice spare for a trip to Alaska or something...
 
If you're pulling positive g don't the tanks think that they're right side up? And enough of a leak to be seen from the ground? Something sounds very wrong.
 
Tim,
Which caps do you have? We have the locking type and they seem very substantial albeit a bit costly.
 
An airplane owner wanting some of his parts to be heavier... so the wind wont blow them away? That is far from typical, but hey, to each his own.

As far as the caps sealing goes.... the seals are adjustable, though I haven't had to adjust any as received from the manufacturer.
 
Does the RV-14 use the same caps as the RV-10?

I've ordered multiple caps from Vans and found that I had to adjust each one for proper fit. I really don't like the Usher caps.

Between me leaving them someplace and the tab breaking, they been a PITA.

I recently switched to Andair locking caps on my RV-10. I really like them. You can't take the key out when unlocked, which means the odds of setting it someplace and forgetting them is slim. Especially if the cap key is one the same ring as the ignition key.

They do reduce the size of the opening, which makes it a little more difficult to fuel. I'm managed to relearn the fueling process, but it isn't a big deal. They are also a bit constrained and you have to deal with the usual Andair ordering process. I ended up purchasing from Aircraft Specialties. Steve was a great help in getting them expedited. Plus he engraved them too.

Naturally, I haven't tested flying upside down in my RV-10.

See you and the family in a few weeks!

bob
 
Catching up...

Here are the replies to the queries so far:

Bob T: Yes, it was still positive G's, but the tanks were pretty full yet. And yes, I was about 1800-2000 AGL when they could see it. They saw the fuel spray coming out of the tanks and let me know. So I did another roll looking out the side window (that gets you dizzy quick :eek: ) and saw it for myself. They actually said "it looked like it was quite a bit of fuel". I don't think the actual volume is all that much though...it just fans out so much it's very noticeable. By the back of the wing the fan of fuel was probably at least 10-12" wide. I'm guessing with the roll, there is a little bit of centrifugal force that the fuel maybe slightly moves outwards. I'm guessing with much more empty tanks I wouldn't see this. But, I must say I've been seeing a bit of blue fuel staining on my flaps lately and now I know where it came from. The -14 BTW is very nice with rolls. Split-S's were fun too.


woodmanrog, I have the standard RV-14 caps. I don't know what they would be called exactly. They're a mostly plastic cap, that has 2 sections that rotate and lock in. They aren't the expand-to-seal type that the RV-10 used.

The other thing that I don't like about them is the fact that the stock color is kind of ugly. It's somewhat of a yellowish tan color. So this means that you really are forced to paint them. We had a fly-in this weekend and an RV-9 guy came by and wondered why I painted my caps...he said "I tried painting mine at first but they chipped all up like yours are starting to." Well, yeah, mine already have a couple of paint chips in them, especially since they blew off the wing. I painted my RV-10 caps and they chipped up too, but eventually I got some nice engraved ones that have the fuel type and my N-Number on them, and those I left raw aluminum.


Scott, yeah I'd gladly get some heavier caps if I could get aluminum, leave them unpainted and get them engraved. If you have any manufacturer info that you can send me offline or in a PM, I can check with them to see if they offer an aluminum variant. If so I'll go that route. The caps are nice otherwise, and the locking method is convenient. They open nicer than the expand-to-seal types. I also like the pretty anodized neck rings they came with...but I'm hoping for a different material option.

If they don't make them in an aluminum variant, I'll check into having a production run of some top-halves in aluminum. At least maybe that way people could retrofit an aluminum top onto their caps and get them engraved.

Bob L,
No, these aren't like the RV-10 at all. I actually would prefer non-locking caps. I don't need the extra inconvenience of the key or anything, but, if Andair makes one that will fit the -14, I'd consider it. I'll maybe bring some
tape to seal off the open tank at OSH and bring my fuel cap to their booth.
At least we're only a few weeks away now!

I'll try to remember to take some pics and post them so that people can see what they're like.

EDIT: Here is a link to the page on Vans site for the caps we get with the RV-14. They're the T-00007 type.
http://vansaircraft.com/cgi-bin/store.cgi?ident=1467045814-16-675&browse=misc&product=delux-cap

Also, if you go to the retrofit locking type cap page, it says specifically that they can't be used on the T-00007 flanges used in the RV-14 wings.

http://vansaircraft.com/cgi-bin/store.cgi?ident=1467045814-16-675&browse=misc&product=retro-cap

So if you build per-plans, you will lessen your options on what fuel caps you can use. But, if you don't go per plans, I don't know if there is any guarantee that the other cap flanges will fit. The RV-14 being all pre-punched, fits the T-00007 flanges. So we're probably going to have to figure out a different solution than most other RV's are using. Ideally, we can talk to the manufacturer and see if they'll make aluminum top halves. If not, I'll have to see how complex they are and maybe make some up like with the axle extensions on the RV-10. If I do it, it'll be a one-time group buy type situation. If I can get the seals to stop leaking though, there will be a limit to how hard I'll try to get aluminum tops. I'd really prefer them, but first I just want them to seal.
 
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Tim, have you tried tightening your caps? I recently did the leak test on my tanks and initially the caps leaked so badly I couldn't even pump the manometer up to 0.5 psi...it was leaking out faster than I could pump it in. I tightened them up a bit and afterward they were almost leak-free. One of them still leaked very slowly so I used a piece of vinyl tape to complete the pressure test, but the point is, there's no way you should be venting any visible amount of fuel overboard in flight. If they fit that loosely you're also going to get water in the tanks the first time you park it outside in the rain.

The tightening process works a bit differently from the aluminum caps Vans used prior to the -14. On the aluminum caps where the rubber o-ring is being compressed between the top and bottom halves, there's a fine line between getting it tight enough to seal vs. so tight that you break the roll pin trying to close it. The caps on the -14 are designed such that the lower half of the cap must be inserted into filler neck in a specific orientation, then rotated 90 deg clockwise (using the open tab on top of the cap), and when the tab is closed the lower half is being pulled up against the bottom of the neck flange. To tighten the cap you simply turn the nut until you can no longer rotate the locking tab clockwise after inserting it into the filler neck. Then back it off just slightly so you can rotate the tab clockwise and then fold the tab down. If that's not tight enough then there's something else going wrong that you can't fix by tightening.

Overall I think the design of the -14 fuel cap is an improvement over the previous models, but it is plastic and may not be as robust in the long run. We'll see. If you decide to paint them, you might want to get some primer made for plastics. All the major paint shops carry it because cars have plastic bumpers, and primers designed for metal surfaces don't adhere well to plastic. I used the car bumper primer one time on an R/C model helicopter body and it held up very well including several crashes...:eek:
 
No, I haven't tried to tighten mine yet. I'll have to do that. I'll lube and tighten them and see if that seals them up. You're absolutely right about the water. Every year at Osh I get dumped on and you definitely pick up water from leaky cap o-rings.

The plastic paint is a good idea as well. Sadly, if you do that, you'll probably have to paint them some other color than your base paint, because finding plastic paint to match may be tough. A contrasting color may be better.

Attached you can see pics of my fuel caps, and the mechanism that is being described. I agree that in general the fuel caps are a better design (as long as these can be sealed tight). I just think the material chosen is a poor choice.
I'd prefer a nice aluminum cap, and then engrave them. It does appear that these are engraveable. It looks like Aircraft Specialty does them:
http://www.aircraftspecialty.com/engraving.html

These are the SPRL caps. I'll have to see what info I can find on them. I'm not going to stop and tear mine apart right now, but if I could have a new top machined I'd do it. For the time being, I may have to buy new caps if I can't strip off my paint. Below are the pictures of my caps. I would recommend NOT painting them if you're using these caps....at least not unless you have a better paint to use for the job. Remember, mine has been flying less than 2 weeks and if they look like this now they're going to be downright ugly in a year or two.

Edit: Now that I've googled "SPRL Fuel Cap" I see you can buy these in a locking version for people that want that. Hopefully I can track down the actual manufacturer and inquire about an aluminum top.

RV14_Fuel_Cap_02.jpg


RV14_Fuel_Cap_03.jpg


RV14_Fuel_Cap_04.jpg


RV14_Fuel_Cap_05.jpg
 
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I help with a set of RV-14 tanks and agree, the caps are not good. While Van's must have had a reason to use these, they just have a cheap feel to them.

I suspect however that the pre-punched hole in the tank skin is too large to install the standard Van's aluminum flange and cap - but if I was building an RV-14 I'd try real hard to find a way to use the standard flange and cap.

Carl
 
The plastic paint is a good idea as well. Sadly, if you do that, you'll probably have to paint them some other color than your base paint, because finding plastic paint to match may be tough. A contrasting color may be better.

Actually it's just the primer that is specific to plastic surfaces. You can use the same top coat paint that you use everywhere else on the airplane. That's how cars are painted. The steel surfaces get a different primer from the plastic panels and bumpers. Then the whole thing gets painted with the same base/clear color paint system.

The biggest downside of using a primer for plastics on the fuel cap is that you'll probably have to buy some minimum size (pint or quart) that is 100 times more than you need for the job. So it's wasted money that might be better spent on metal caps if there are any available that fit the filler neck.
 
Actually it's just the primer that is specific to plastic surfaces. You can use the same top coat paint that you use everywhere else on the airplane. That's how cars are painted. The steel surfaces get a different primer from the plastic panels and bumpers. Then the whole thing gets painted with the same base/clear color paint system.

The biggest downside of using a primer for plastics on the fuel cap is that you'll probably have to buy some minimum size (pint or quart) that is 100 times more than you need for the job. So it's wasted money that might be better spent on metal caps if there are any available that fit the filler neck.

Just take them to an auto paint shop. Higher end shops have paint mixing systems on site and will mix very small quantities. Just get them to prime when priming a bumper cover, they do a lot of them.
 
I got a hold of the manufacturer today and they confirmed they have nothing in aluminum. So I'm going to take some time after OSH and draw them up in CAD and then send them out to have some new aluminum tops made. If there is enough interest, I will see about quantity discounts. I wouldn't want to make anything on them, but I know from people who've had parts done before that quantity can reduce the price by more than half.
I'd have the top half and the flip tab all done in Aluminum, but leave the bottom half plastic just to save cost.
 
No, I haven't tried to tighten mine yet. I'll have to do that. I'll lube and tighten them and see if that seals them up. You're absolutely right about the water. Every year at Osh I get dumped on and you definitely pick up water from leaky cap o-rings.

The plastic paint is a good idea as well. Sadly, if you do that, you'll probably have to paint them some other color than your base paint, because finding plastic paint to match may be tough. A contrasting color may be better.

Attached you can see pics of my fuel caps, and the mechanism that is being described. I agree that in general the fuel caps are a better design (as long as these can be sealed tight). I just think the material chosen is a poor choice.
I'd prefer a nice aluminum cap, and then engrave them. It does appear that these are engraveable. It looks like Aircraft Specialty does them:
http://www.aircraftspecialty.com/engraving.html

These are the SPRL caps. I'll have to see what info I can find on them. I'm not going to stop and tear mine apart right now, but if I could have a new top machined I'd do it. For the time being, I may have to buy new caps if I can't strip off my paint. Below are the pictures of my caps. I would recommend NOT painting them if you're using these caps....at least not unless you have a better paint to use for the job. Remember, mine has been flying less than 2 weeks and if they look like this now they're going to be downright ugly in a year or two.

Edit: Now that I've googled "SPRL Fuel Cap" I see you can buy these in a locking version for people that want that. Hopefully I can track down the actual manufacturer and inquire about an aluminum top.

RV14_Fuel_Cap_02.jpg


RV14_Fuel_Cap_03.jpg


RV14_Fuel_Cap_04.jpg


RV14_Fuel_Cap_05.jpg

They are indeed the Newton SPRL Caps. And we do engrave them. However, we no longer offer color fill in for the engraving. The caps are extremely porous and they don't color fill as nicely as I would like to see.

Personally, if I was building a -14 and had not yet installed the flanges, I would seriously consider seeing if I could utilize a different flange and cap. Newton makes some really nice locking caps as does Andair.

If Tim goes about having aluminum tops machined we will be happy to get the dimensions and make a fixture to engrave the new aluminum tops.

Have a great holiday,
Steve
 
I do hope to have some made up. I've had a couple people ask me offline to keep them posted because they want them too. I'll do that for sure, and follow up here when I do something. It won't be until after OSH for sure...too many things to do. I haven't yet taken the time to tighten mine or take them apart to measure them or anything...but I did get my wing blue again today after a couple of rolls with 1 tank that was full. So I guess I better at least tighten them soon.

If anyone finds a source for a single fuel cap without the flange I'd perhaps be interested in buying one just so when I rip mine apart I don't have to worry about messing something up. I like to keep spares of many things, and a spare fuel cap would be nice. As it looks, it's going to cost just under $60 to buy a single cap and I can only get it with a flange at this point.
 
Tim,

We have that cap on our Europa. Over ten years now with no problems. We disassemble and lube the orings every year. Be sure to lube the small one on the shaft. We park outside several weeks each summer and no problems with rain leaking into the tank. The orings are metric but available from McMaster.

Jim Butcher
 
Hello Tim, I would be interested to buy from you aluminum "tops" as replacement for the plastic standard Vans caps. Are you able to sell some to me?
Thanks.
Renzo Corvetta
Italy
 
piece o cake!

Hey Tim:

Do you see the SS locknut on the bottom of the cap? This sets the 'squish' on the O ring. Sounds like yours are a bit loose - tighten slightly until you get the seal you want. I thought Robin had a locking metal replacement version, but I don't see it on his website now.

I have a whole box of these here - surplus to my needs. Just sayin'...

Carry on!
Mark
 
Antisplat product?

Perhaps Alan at Antisplat would be interested in making the desired aluminum version of the cap?
Just a thought.

Erich
 
For those interested, it's being worked on. I did send it to a vendor who produces parts for RV's, and once they're done I'm guessing they will offer them and offer them engraved, also. I haven't checked on the status lately but plan to next week to see if there is any progress.

I did tighten mine and also lubed them, and they don't leak much if at all anymore, so that is good. I'm still left wanting aluminum, however, for the many reasons I gave. They will look much better as well. At least the plastic ones are useable the way they are.

I'll keep you posted here when they are available.
 
Hey Tim:

Do you see the SS locknut on the bottom of the cap? This sets the 'squish' on the O ring. Sounds like yours are a bit loose - tighten slightly until you get the seal you want.

Carry on!
Mark

This is a common misconception, at least regarding the original Van's fuel caps. You loosen the nut and turn the lower half of the cap assy to adjust the seal, then tighten the jam nut again.
 
This is a common misconception, at least regarding the original Van's fuel caps. You loosen the nut and turn the lower half of the cap assy to adjust the seal, then tighten the jam nut again.

Correct (unless you are still using the early design of the cap, it adjusted with just the nut), but the caps being discussed here are not the Usher Enterprises caps that have been commonly used on all the other RV models.
 
Just bringing this conversation back up to give the news that the place that's doing the new aluminum top pieces has now produced a test piece, then reworked it a little and produced another one that works great. They're headed away for a couple weeks but then will do one out of aluminum and it sounds like it won't be too awful long and they may be available.
Everyone who gets the standard fuel filler neck will still have and probably need their old caps anyway, so go ahead and build on, but if you are hoping for aluminum and engraved, it looks like it will happen.
 
Just bringing this conversation back up to give the news that the place that's doing the new aluminum top pieces has now produced a test piece, then reworked it a little and produced another one that works great. They're headed away for a couple weeks but then will do one out of aluminum and it sounds like it won't be too awful long and they may be available.
Everyone who gets the standard fuel filler neck will still have and probably need their old caps anyway, so go ahead and build on, but if you are hoping for aluminum and engraved, it looks like it will happen.

Great, thanks Tim, please keep us posted.
 
New RV-14 Fuel Cap Tops by Aerosport

Hey All, it's a great day for showing off something new that I've been waiting for...

Aerosport Products is the place that did that did the machined, engraved, aluminum tops to replace the "el' cheapo" looking plastic tops of your fuel caps. http://www.aerosportproducts.com/about.htm

I received my set of aluminum tops yesterday and they fit perfectly!

Note: You replace just the tops of your old fuel caps, keeping all of the other parts. The new caps they are planning to have pre-engraved with "100 LL only 25 US Gal" to help you comply with marking requirements for your inspection. The N-Number engraving I had done is extra, because that will require the fuel caps to be taken back for machining and a machine setup would be required for that. You'll want to talk to Aerosport for the details.

Geoff didn't tell me to do this but... if you have interest in them, maybe give them a call or email just to let them know. It may be nice for them to get an idea of how many people may be wanting them before they fire up for a production run. It could prevent delays in the event that there are many.

I'm very happy with how they turned out. They look so much better than the plastic, and maybe now they won't blow off my wings when I'm fueling up. I'm going to keep them unpainted, especially since they are engraved.
The engraving of the N-Number is a nice touch. If you ever lose a fuel cap, maybe the finder will have a way to track your address down and send it back to you.

Anyway, here are some pics! (I have larger ones on my website)

RV1420161107-161539-003m.jpg


RV1420161107-161540-004m.jpg


RV1420161107-175800-005m.jpg


RV1420161107-175807-006m.jpg


RV1420161107-180442-008m.jpg
 
Looks good Tim, I was planning on purchasing a spare plastic one incase I lost one, now I will probably give Geoff a call. Have you tested them in a roll to see if they are tight yet?
 
The engraving of the N-Number is a nice touch. If you ever lose a fuel cap, maybe the finder will have a way to track your address down and send it back to you.

Along with a bill for the replacement windshield for their Corvette......;)
 
Hey Ron,
No, I haven't rolled with them yet. Maybe this week if I can get out of work.
I miss Daylight saving's time. It gets dark too early after work these days.
I don't expect any issues, because the stem seal doesn't fit inside a real capture groove on them around the stem (on either the plastic or aluminum). So they should seal the same as the original. The o-ring groove for the big o-ring is also identical and fits nicely. So if they leak it'll just mean I have to tighten the nut again like I did on the plastic ones. One day I'll have to measure up for o-ring sizes so that I can keep a couple of o-ring spares for the caps on hand. If I find some that are right, I'll post it here. It would be a good idea for us all to have spare o-rings handy over the years. I'll look for viton ones. I'm also going to get some replacement nuts. I haven't sized them yet but I believe they are probably metric. Wouldn't hurt to have spare nylock nuts on hand.
 
The new caps they are planning to have pre-engraved with "100 LL only 25 US Gal" to help you comply with marking requirements for your inspection.

I'd be careful with that marking, especially since it would be engraved and not easily changeable. If an unleaded avgas ever comes along I think you'd technically be violating your placards by using it. And anyone running mogas would also technically be violating it.

IMHO a better marking would be "XX gal XXX min octane" or something like that.
 
Hey Ron,

Yesterday I did get a chance to roll test the new caps, with full fuel tanks and only me aboard. No leakage at all. Very happy now. It was a windy day too, and they didn't blow off the wing anymore. ;)
 
Glad they solved the problem for you Tim. One of those things I'll need to get around to ordering. Just ordered a few more items for this winter projects. Replacing the caps will not be a long project.
 
Just wanted to let RV-14 builders know we have the aluminum replacement caps
in stock. The cost is $145.00 per set and if you would like your N-Number engraved it is an additional $45.00. These are not on the web site yet so direct
order would be the best at this time.


Geoff Combs
614-834-8659
http://www.aerosportproducts.com

0_0_796b09c26bbafcd8799fe84c8568d6c4_1
 
All aluminum (Top) RV-14 caps - please !

I am still in search of caps for my 14. Prefer at least all aluminum caps (Including the lift "tab") or better yet locking all aluminum caps. I am not sure if the Andair locking all aluminum caps will fit the SPRL flanges. Has anyone tried these? I was informed that the tab had to remain plastic or else galling would occur. Seems a thin plastic washer that you change every 10 years might help this issue but since I'm not a metallurgist anyone with more knowledge than me welcome to input. I understand properly adjusted the Vans caps will/might work just don't want to use light weight plastic caps on my airframe.
 
RV-14 caps

I've 3D printed the center "tab" but my goal is to CNC one from aluminum. Aerosport makes a nice cap (Which I ordered). I can 3D print the tab to give it a color as I don't trust painting and later chipping. Aerosport is concerned with galling (With an aluminum "tab") but I think I have a system that should eliminate this issue.:eek:
 
I got my caps from Goeff at Aerosport and they are the best. I've had mine on for about a year and a half and have not had the first problem. I had mine engraved. Of course they meet the regs as far as labeling. I put red paint in the engraved part and polished them. These caps are definitely professional looking.
 
Sorry to revive this thread.

Has anyone had these polished and clear anodized like the old "deluxe" caps? The new metal version for the RV-10 looks much better than the plastic but still a little rough. Thanks!
 
Say what you want about the plastic fuel caps ... but they don't dent or scratch the sh$t out of your airplane when dropped :p

(mine have been great so far, albeit you can't get them clean without a toothbrush)
 
I'm thinking I may need to get some better fuel caps than the ones that came with the RV-14 Kit. Does anyone know if they're standard enough that I can buy a set elsewhere? I tried my spare RV-10 caps in them but they are smaller than the RV-14 fuel caps.

The reasons are twofold:

1) a couple times now when I've been fueling, I set the caps on the wing walk area, and the wind has blown them off the plane and back by the tail on the ground. They're just so light, which is sometimes a good thing, but in this case, if it's happened twice already in just over a week, it's going to be a long-term pain.

2) Today when I was doing a few rolls near my house (I live in a barren area), the kid and wife looked up and texted me that I was leaking fuel from both wings. I decided to look sideways on the next roll and sure enough, both fuel caps were just pouring out a fan of fuel while I was upside down. And, I wasn't at all negative when it happened (although the tanks were prob. at least 3/4 full).

Maybe I can change out the seals to larger o-rings or something and fix #2, but considering I'm not already that keen on these plastic fuel caps, if there is a source for good aluminum ones that fit, I'll probably just have some engraved ones made and replace these and keep it as a spare. Being light plastic, it would be a nice spare for a trip to Alaska or something...

Hi Tim,

Did you tight a little the nut under the fuel cap to increase pression on the O-ring ?
 
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