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A Little Paranoid

Av8torTom

Well Known Member
OK folks, I've been worried about this part of the build since I got my empennage kit - The Firewall Forward Fuel System.

First let me say that the plans call for VA-129 to be run from the gasocolator to the fuel pump. I found this hose to be too long, so I used VA-139 instead which is shorter. Using VA-129 from the fuel pump to the carb seemed to be a good length.

Please tell me if this looks right mostly because I have some fittings that I can't identify (for example KB-000), and want to be sure I'm using the right ones:

Gascolator to fuel pump
Slide2_zpsgvpkoqvb.jpg

Slide3_zpsal6wfr2t.jpg


Fuel pump to carb and fuel pressure line
Slide4_zpsfcpqblvp.jpg


To carb
Slide5_zpsyihcet34.jpg


Of course I still have the various plugs to install.

Thanks!
 
I have no way to look at plans here at home so I can't check, so something you should keep in mind is that during start-up and shut down, the engine moves in rotation. A lot.
Since the carb is down low on the engine it moves a lot laterally. That means their must be slack in the hose to allow that to happen. A way to do that is to have curve to the hose shape. Because of that, you using a shorter hose between the gascolator and pump concerns me. You photos don't do a good job of showing whether it is an issue or not but it appears you may have a hose strung in nearly a straight line between the two point. This would not be good. the rest of the installation looks fine.
 
I agree with ave seen people want to be “neat” and have Hose’s going direct from point to point - and you can p I’ll the ends right out of the Hose with engine movement that way. Since you bought a FWF kit that had everything thought out for you, why not use the lengths they gave you? Unless, of course, you changed components locations.
 
Thanks Scott. Here?s the line from the gascolator to the fuel pump.
I couldn?t use the longer hose without it kinking

 
I?ll try again switching them and see how it looks. Maybe rotating the input fitting on the fuel pump can take up some slack
 
Tom there should be a 45 degree fitting from the gascolator. It will take care of all the kinks of longer hose you are talking about.
 
Your post #4 picture doesn?t look like there is enough slack in that fuel line. As Scott says, the bottom of the engine where the fuel pump is, moves laterally a lot, especially during start up and shut down.
 
Personally I would get rid of the aluminum fitting on the carb inlet and go with steel. I don't like aluminum on fuel lines firewall forward.

Bob burns
Rv-4 n82rb
 
The carb and pump don't really move relative to each other so that line doesn't need as much slack. The movement is in the gascolator to pump line. That one looks a little short. I would recommend Tom at TS flightline to make one the length you need.
 
my gascolator fuel line. I believe items close to the engine centerline and close to the engine attachment bolts experience rotation but not much translation.

I added a little bracket to the exhaust pipe at the heat muff to prevent sliding down the pipe.

for the small pipe fittings, I used steel.

IMG_20150704_170113_zpsnwxv3csd.jpg


IMG_20150427_204917_zpsbulxczhb.jpg
 
Last edited:
What Vlad said.

What Vlad said. You need more slack in that line from the gascolator to the fuel pump.
 
Thanks everyone

Thanks everyone - This forum is just amazingly invaluable!!! I will switch the lines today and report back. I was actually looking at the wrong drawing which explains why I missed the 45 elbow from the gascolator that Vlad mentioned.

Doug, thanks for making me your poster child - again... :D
 
Seems much better

Swapped hoses using correct fittings and it's much better - thanks again everyone...

Gascolator to fuel pump

77B8F7C6-43A3-43A4-AD93-9C041A20C14D_zpsuvhiovmm.jpg
 
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