Esser's Build

[jiott]

Yep, I used that same tape too and they are still not showing any signs of coming loose after 400 hours (3 years).

[Esser]

Well I am trying to ease back into building but it's slow going.

I need to order more stainless strapping to finish the oil cooler/rad brackets because there wasn't nearly enough to do the job the instructions called for. I thought this was mildly inconvenient that they didn't send enough.

I cut the windows and they are in place but not permanently attached yet.

I'm working on the oil system. There also wasn't nearly enough line to do that job either so I have to order more hose.

Because I am adding a fuel injection system, there is a lot of moving around of things that I have to do. I have to order more 5/8" coolant line so I can move the coolant pressure tank off the top of the engine to the back somewhere. I'm not sure if it has to be secured somehow. When I took it off I I recall it just sitting on the engine.

Also with the fuel injection system, I have much higher fuel pressures and because of this, I have opted to put my fuel pumps on the engine side of the firewall. I went to install the firewall bulkhead fitting and it's not even close to fitting in the hole that was predrilled in the firewall. Do I have to widen that out to install the fitting or do I have the wrong part? Here is a picture of the fitting I am talking about.

[jrevens]

...I went to install the firewall bulkhead fitting and it's not even close to fitting in the hole that was predrilled in the firewall. Do I have to widen that out to install the fitting or do I have the wrong part? Here is a picture of the fitting I am talking about.

That looks like the fitting I got Esser... turn it around to the fitting side - the weld bead won't fit in the hole. That may be the problem.

[Esser]

Thanks for the quick reply John, even if I flip it around, it is about 4mm too big for the hole and in the instructions it looks like the weld side should be down against the firewall.

[jrevens]

You're right, but I ended up putting the weld away from the firewall. It seems like the fitting fit into the hole for me, so I don't know what's going on with yours. In the picture it looks a little off-center with the disk it's welded to also. Maybe time to talk to Debra. You could enlarge that hole a little bit with a drum sander if you wanted to.

[Esser]

I think I will see if someone I know has a Knock-Out Punch and put a larger hole. Due to my fuel pump moving to the other side of the firewall, I think I would like the hole lower anyhow. As always, I appreciate your input John.

[Esser]

So I may be over thinking this, but I thought some extra opinions might be nice. As stated before, I am installing en EFI kit. Since the fuel pressure after the pump is over 45PSI I want to have the pump on the engine side of the firewall so that no high pressure fuel is in the cockpit.

I was thinking of using the same entry point into the firewall as whats called for in the Kitfox instructions but it is almost the same height as the the top of the header so I was thinking about lowering it as much as I could. Thoughts on this might would be appreciated. I was also worried about having air in the system but I think if I bleed the air out of the fuel block which is the high point in the system after the header tank that should be fine.

Here are some pictures for roughly running the fuel line. Your comments would be appreciated.


The first picture, Pink is the gravity fed supply line to through the firewall to the existing hole and yellow is the low pressure return to the header tank.


The next picture shows the pink - gravity pressure supply, the green - dual fuel pump, the orange- high pressure supply to the fuel block, blue - high pressure return from the injectors to the fuel regulator, and yellow - low pressure return.


Should I try to put the pump lower and bring the gravity fed line through the fire wall lower so the pumps aren't at the top of the header tank in level flight?

Also, the Kitfox supplied fuel shot off valve seems really constrictive with it's ID, has anyone upgraded?

[BobRS]

Josh
I'm obviously further along in the operation of my 914 than you are, but I remember vividly some of the points you ask about in this thread.

1) The firewall fuel boss looked like yours. I punched a bigger hole in the firewall.

2) The instructions may have you use 3 rivets to mount the flange to the firewall...use more.

3) Ours is a tri-gear, yours is a tail dragger, but here's the interesting thing, we mounted the 914 fuel pumps behind the pilot's seat on a plate mounted to the structural members. We didn't buy the EFI, so its the standard Rotax carbs with stock electric pumps. I mounted them there, since the build instructions originally had them under the center panel. It become too crowded so I decide to relocate. Not ideal, but I plumbed with aluminum tubing throughout (inside the cockpit) instead of hose. Started with the tubing that came with the kit...just bought more from Spruce. That includes the fuel shutoff valve, fuel pump connections, and running up to the inside firewall. If you do this, buy plenty of tubing...you'll need it.

4) I don't know if your EFI kit requires the use of 2 check valves. Our Rotax installation instructions did. Again, a plumbing nightmare, but they work. We did a fuel pump OFF flow check through the firewall, and it is surprisingly very good with the high wing tanks. I have the measurements, but I'm too tired to dig them out.

5) One VERY important note. Its in the builder's manual, but often over looked. The hoses coming out of the wing root down to the header tank HAVE to be routed carefully to have the good flow mentioned in (4). We didn't get it right the 1st time and one wing tank drained before the other and gravity fuel flow sucked.

6) So this last comment is for anyone reading this post that has purchased a 914 for their KF w/o the EFI kit. If everything goes right, it is possible to have 914 engine life w/o fuel pumps on (sorry Josh, I just don't know ab your EFI), but John McB will tell you...don't expect to maintain altitude. If you take transition training with Paul at Stick & Rudder, you'll do this. The 914 stutters at high RPM with the pumps off. Our 914 runs fine at lower RPM (4000) on the ground with no fuel pumps on. I did this in preparation for things I'll be trying during Phase I. Josh, I'm interested to hear the details of your EFI system when you finally run up the engine.

BobRS
KF SS7, N104Y, Rotax 914
Albuquerque, NM

[rosslr]

HI Josh,

I'm rushing a bit so excuse me if I haven't read your post well - but have you looked at the FWF setup that Kitfox suggests for the 912is? As you know it is fuel injected and the fuel is at about 45psi after the pumps. The pumps are located very low on the engine side of the fire wall. Also worth looking at the fuel manifold that John has made up that houses the fuel pressure sender and a bypass valve in case of the fine filter blocking.

I will get more time next week to catch up on threads here.

Good to see your progress!

cheers

r

[Esser]

OK I put a 1" hole in the firewall for the fuel carry through. My next question is do I need some sort of fireproof sealant between the firewall and the carry through before I rivet it? The instructions don't say anything but I am assuming I do since that isn't airtight