RV-8 fuel system with Vapor Return Lines

A forum in which to discuss topics specific to the assembly of the RV 8/8A
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clreding
Class E
Posts: 117
Joined: Mon Jun 18, 2007 4:09 pm

RV-8 fuel system with Vapor Return Lines

Post by clreding »

I purchased a Eci Titan IO370C4B1T8 Engine for my RV-8, hopefully it will be here in a few days. Based on the documentation I have reviewed so far I will need to add a vapor return line to the fuel system on DWG 82. Back a few years ago I knew I wanted a fuel injected engine and I purchased the Airflow fuel pump from Vans and installed the standard lines. I am now trying to figure out the proper way to plumb this with a vapor return. Im looking for ideas and suggestions. I don't want to reinvent the wheel.

In figure A of dwg 82 the return from the airflow pump is Tee’d into the out line of the originally supplied valve. Is there any reason why i can't just tee it back into the supply line in front of the gear tower?

Original System Drawing
Image

My thoughts
Image

I haven't been able to find any documentation on the Airflow Package from Vans yet.

Next question. Has anyone run Vapor Return Lines to the fuel tanks? I could probably run the fuel and Vapor Return lines through the same grommet hole. The other option would be to add a second small hole a inch or so from the fuel line hole in the fuselage.

Anyone understand why Vans original designed such a large hole in the first place? Why they just didn't add a bulkhead fitting like they did for the vent line?

Thanks
Craig

clreding
Class E
Posts: 117
Joined: Mon Jun 18, 2007 4:09 pm

Re: RV-8 fuel system with Vapor Return Lines

Post by clreding »

Still don't know why the pic's didn't post but here are the links to the images in the gallery

http://rivetbangers.com/forumsGallery/m ... temId=7810

http://rivetbangers.com/forumsGallery/m ... temId=7813

I have an answer to the first question which was can you tee into the line after the gear tower.. YES, in fact the newer airflow fuel pumps have the return set up internally. According to Kyle at Airflow feeding back through the filter is not necessary but does offer some protection if the pump self destructs since the debris would be trapped by the filter. The new versions that they sell do this internally simplifying plumbing.

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