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RV-12iS fuel line photos

subpar_bucker

Well Known Member
I wanted to send a quick post our showing the installation of the fuel lines I purchased from Aircraft Specialty. I've created a shared google photos album (hopefully that works).

https://photos.app.goo.gl/YCMMoV3YdnFKXZWc7

I can say it was quite delightful after humiliating myself fabricating the long fuel lines to simply attach these lines where they belonged in a single attempt :)
 
I'll stick with my two carburetors and deal with sinking floats.

iS plumbing looks like nightmare... :eek:
 
Our little Chevrolet has evolved into a Mercedes!

That fuel pump/filter module looks like it could feed an SR-71 engine. OK, maybe that's an exaggeration ;).

Maintenance of the filters and pumps at annual will be problematic. And once the tailcone is installed fixing any leaks will be a challenge.

It looks like the only access once the tailcone is installed will be through the baggage bulkhead and work around-the-corner, so to speak? It looks like a small person could climb over the fuel tank to get back there but more likely the MM will call for removing it.

It will be interesting to follow the experience with the new airplane and it's many changes. The complexity reinforces my opinion that the iS should be a separate category in the forums.
 
I think there is an outside access door on left side behind rear baggage bulkhead - but still looks like a pain to do inspection/repair...
 
It looks like the only access once the tailcone is installed will be through the baggage bulkhead and work around-the-corner, so to speak?

The iS version of the RV-12 has an access cover added to the bottom of the tail cone, directly below the fuel pumps.
 
The iS version of the RV-12 has an access cover added to the bottom of the tail cone, directly below the fuel pumps.

Yes, I forgot. But it is rather small, you could get maybe one hand though:

i-NgdZNF7-L.jpg


Has another access panel been added? It would take a pretty big access panel to get to all of this from the bottom of the aircraft?

i-LcKzVr2.png
 
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That's the access cover for the fuel injection pumps, filters, and associated plumbing located behind the baggage rear bulkhead???

I guess maybe take a few pics before attaching the tail cone...
 
Yes, I forgot. But it is rather small, you could get maybe one hand though:

i-NgdZNF7-L.jpg


Has another access panel been added? It would take a pretty big access panel to get to all of this from the bottom of the aircraft?

i-LcKzVr2.png

I'm not sure what you mean by "get to all of this". Everything you see can be reached through the designed opening. For those that want to stand behind the pumps when working on them, you will have to remove the tail cone I guess.....

The only item that needs to be removed during inspections is the black Andair prefilter.

The silver Rotax filter (up near the top) gets changed initially at 100 hrs and then 200 hr intervals after that. It would be difficult to change working through the bottom access hole, so that is best done through the baggage bulkhead opening.
I am not a young guy anymore but I have had no problem accessing it that way. In our shop we have a piece of plywood that fits the baggage floor. Because of the different fuel tank design, with the seats removed, it is possible to climb into the baggage area and sit on the baggage floor while accessing the fuel pump assembly (may require a tail stand to prevent he fuselage tilting onto the tail).
 
What is dimension of "designed opening"? Are you able to lay down and stick your head/arms/shoulders through the opening?

Maybe someone can show a pic of the entire bulkhead with the opening...
 
What is dimension of "designed opening"? Are you able to lay down and stick your head/arms/shoulders through the opening?

Maybe someone can show a pic of the entire bulkhead with the opening...

Section 10 shows the access opening in the bottom skin.

i-7fwZQx6-L.png


As I said, you could get one hand through the opening.
 
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I'm not sure what you mean by "get to all of this". Everything you see can be reached through the designed opening. For those that want to stand behind the pumps when working on them, you will have to remove the tail cone I guess.....

The only item that needs to be removed during inspections is the black Andair prefilter.

The silver Rotax filter (up near the top) gets changed initially at 100 hrs and then 200 hr intervals after that. It would be difficult to change working through the bottom access hole, so that is best done through the baggage bulkhead opening.
I am not a young guy anymore but I have had no problem accessing it that way. In our shop we have a piece of plywood that fits the baggage floor. Because of the different fuel tank design, with the seats removed, it is possible to climb into the baggage area and sit on the baggage floor while accessing the fuel pump assembly (may require a tail stand to prevent he fuselage tilting onto the tail).

OK, thanks, questions answered. I think they were pertinent questions; ease of maintenance is a valid concern.
 
Section 10 shows the access opening in the bottom skin. As I said, you could get one hand through the opening.

No, I mean the "Designed Opening" in the baggage bulkhead. Can you lay down in the baggage compartment and stick your head/arms/shoulders thru the opening so you can see and work on the plumbing?
 
Another question… with all those hose clamps… wouldn’t it be a good idea to safety wire so they don’t loosen?





 
Another question? with all those hose clamps? wouldn?t it be a good idea to safety wire so they don?t loosen?






In all my years working on aircraft professionally, I have never seen a screw type hose clamp loosen, so I am not sure how to answer that question.

Some would say why not? I guess my answer would then be, if it makes you feel better, then safety wire them, but that line of thinking would also make ever using a self locking nut a bad choice.

Bottom line.... use of safety wire is not deemed necessary so it is not specified in the KAI, but if it makes someone feel better, there is nothing wrong with doing it.
 
Thanks for posting those pictures I was curious about the size of the pumps etc for the injection engine.

Great job on the lines that looks super clean !

I?m not sure why the negative comments because that looks very simple to me considering you have two pumps and it?s all in one place to inspect, that?s a great design.
 
I?m not a 12 builder, but that sure looks like a lot of plumbing. Why wouldn?t you guys use a duel fuel pump setup from SDS or EFII? The way the fuel pumps are mounted in their manifold would really clean things up for you guys. Walbro fuel pumps along with an SDS or EFII duel fuel pump manifold and simple pre and post pump Holly reusable filters would surely clean all of that plumbing up. I?m installing an electronic fuel injection setup with a duplex fuel selector valve with return lines on my -7 build and I?m using the SDS/EFII fuel pump/manifold and it really works well and simplifies things.

Mark
 
I?m not a 12 builder, but that sure looks like a lot of plumbing. Why wouldn?t you guys use a duel fuel pump setup from SDS or EFII? The way the fuel pumps are mounted in their manifold would really clean things up for you guys. Walbro fuel pumps along with an SDS or EFII duel fuel pump manifold and simple pre and post pump Holly reusable filters would surely clean all of that plumbing up. I?m installing an electronic fuel injection setup with a duplex fuel selector valve with return lines on my -7 build and I?m using the SDS/EFII fuel pump/manifold and it really works well and simplifies things.

Mark

The RV-12 and 12iS are certified airplanes. The Rotax 912iS is a certified engine package.

The parts and all of the associated plumbing you see in the photo is either specified for and supplied with the engine by Rotax or is designed to meet a long list (many pages) of engineering requirements for the engine installation.

Bottom line.... Eyeball engineering is not allowed in this situation, and knowing the complexity of the 912iS engine, even if it was it would not be a good idea.
 
Roger that! Has anyone built a 12 (EAB) with an Edge Performance 912 EFII/turbo? I?ll bet that would be one heck of a performer!! When I?m finished with my current -7 project I?m planning on building a Rans S-7 with the EP-912 EFII/turbo setup.

Mark
 
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Roger that! Has anyone built a 12 (E-LSA) with an Edge Performance 912 EFII/turbo? I?ll bet that would be one heck of a performer!! When I?m finished with my current -7 project I?m planning on building a Rans S-7 with the EP-912 EFII/turbo setup.
Mark

Correct me if I'm wrong, but I don't believe the RV-12 E-LSA kit is available with a turbo. That would have to be built as an EAB.
 
....I have never seen a screw type hose clamp loosen....

Scott, I've seen a few loosen. I now safety wire all of them.

However, Ive got to say that the only ones that loosened were on the engine manifold or otherwise attached to an engine. Haven't seen any loosen elsewhere, yet.

Key word, "yet." Safety wire them.

And if the airplane doesn't have it designed in, add a drain hole to the belly so that when fuel does leak, at least it'll drain out. Something I still need to do for my RV-3B under construction.

Dave
 
Correct me if I'm wrong, but I don't believe the RV-12 E-LSA kit is available with a turbo. That would have to be built as an EAB.

Sorry Mel, you?re correct. So please insert EAB in the place of E-LSA. As a matter of fact, I?ll edit my post.

Mark
 
Scott, I've seen a few loosen. I now safety wire all of them.

However, Ive got to say that the only ones that loosened were on the engine manifold or otherwise attached to an engine. Haven't seen any loosen elsewhere, yet.

Key word, "yet." Safety wire them.

And if the airplane doesn't have it designed in, add a drain hole to the belly so that when fuel does leak, at least it'll drain out. Something I still need to do for my RV-3B under construction.

Dave

I have seen screw clamps on rubber hoses like used on the induction system of a Lycoming loosen over time, but it is not because the clamp loosens so I was not counting those when I wrote that. Those loosen because the hose shrinks and or gets compressed. Even then it is not a standard practice to safety wire them on a Lycoming engine.
When screw clamps are mounted on something non compressible, they don't loosen. At least not in an application like this.

BTW, hose shrinkage/compression is the reason that I replace the screw hose clamps on a Lycoming with constant tension spring clamps. I just did this on my personal airplane while installing the o-ring seal flanges on the induction tubes that are available from Ross at SDS Aero Products. The spring clamps are even more worthwhile on the oil return tubes, because being aluminum, the expand and contract a lot which causes the hose sections to get loose over time under the fixed tension screw clamps. The spring clamps will always be tight and leak free.
 
Thanks for posting those pictures I was curious about the size of the pumps etc for the injection engine.

Great job on the lines that looks super clean !

I?m not sure why the negative comments because that looks very simple to me considering you have two pumps and it?s all in one place to inspect, that?s a great design.

The rv12is provided a great opportunity to fully utilize CNC tube bending technology to provide drop in lines for the 12iS aircraft that the OP of this message utilized in his aircraft.

Here is a video that shows the design process, fabrication, as well as tube final dimension verification.

https://www.youtube.com/watch?v=MPJnjjaBMVs

The 10:22 mark is where the actual tube bending begins. The rest of the video shows how the entire process is done from start to finish.

As always, we couldn't have done this without the help of some great beta testers. The RV/ Experimental community is comprised of some great people, and we really enjoy working with you to refine and improve the build experience.

Steve
 
Nice.
When I worked as a maintenance electrician for AC Spark Plug (1980ish) we used tube benders similar to this for mass production of lines for fuel tank units. About 20 benders, running much faster. Definitely an improvement in consistency and accuracy.
 
Roger that! Has anyone built a 12 (EAB) with an Edge Performance 912 EFII/turbo? I?ll bet that would be one heck of a performer!! When I?m finished with my current -7 project I?m planning on building a Rans S-7 with the EP-912 EFII/turbo setup.

Mark

I could imagine 155HP to be an overkill for the RV-12. But staying carbed and using their 1484ccm BigBore kit could be an option.
 
BTW, hose shrinkage/compression is the reason that I replace the screw hose clamps on a Lycoming with constant tension spring clamps. I just did this on my personal airplane while installing the o-ring seal flanges on the induction tubes that are available from Ross at SDS Aero Products. The spring clamps are even more worthwhile on the oil return tubes, because being aluminum, the expand and contract a lot which causes the hose sections to get loose over time under the fixed tension screw clamps. The spring clamps will always be tight and leak free.

What are "spring clamps"?
 
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