Gas tank questions - not sure how to proceed

The stock tank in the Rx7 was arranged with a 3/8 feed line, a 5/16 return line and a 5/16 vent line at the top of the tank.

Now that I am running a fuel injected setup, is there any chance I can get away with using the 3/8 feed (shouldnt be that big a deal) and then maybe the 5/16 for the return? Im worried it wont flow well enough on the return end.

Trying to avoid messing around with cutting the tank and welding stuff.

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

Should be ok. Most everything injected has a smaller diameter return line.

You'll be fine. The Fool Pressure regulator has even a smaller hole...and they work...and most OEMs , especially the Japonaise are 8mm on feed it seems....8mm=0.315" and 5/16 is 0.3125"..

Dont worry, be happy..
Did those miserable bushings arrive yet?

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

arrived today in fact! Trying to arrive a warmish garage to do them in. This whole -2 until 10am thing sucks. Couldnt feel my hands / feet after working on the rx7...

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

If your tank has those stupid quick disconnect fittings on it, I just recently found a slick AN adapter fitting. These adapters are made by Russell and I found them at Summit Racing. I am using them on the tanks and fuel rails of both XRs that I am building.

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Robert.

"You are way too normal to be on Rally Anarchy." Eddie Fiorelli.

Quote
Rallymech
If your tank has those stupid quick disconnect fittings on it, I just recently found a slick AN adapter fitting. These adapters are made by Russell and I found them at Summit Racing. I am using them on the tanks and fuel rails of both XRs that I am building.

Piccie or link? Summits website is horrible to search.

actually its from an 1982 Rx7 originally carburated with a return though

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First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

I am typing from my phone and I don't know how to post links!

You can search "push-on efi fitting" at Russell Performance, Summit or Jegs.

Some examples: 644110, 640860, 640940.

I preferr the threaded collar types like 644110. They come in different sizes fron 1/4 to 3/8 and adapt mostly to AN-4, -6 and-8 I think. Different colors are available. These fittings are good quality and have saved me lots of time.

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Robert.

"You are way too normal to be on Rally Anarchy." Eddie Fiorelli.

Quote
Gravity Fed
The stock tank in the Rx7 was arranged with a 3/8 feed line, a 5/16 return line and a 5/16 vent line at the top of the tank.

Now that I am running a fuel injected setup, is there any chance I can get away with using the 3/8 feed (shouldnt be that big a deal) and then maybe the 5/16 for the return? Im worried it wont flow well enough on the return end.

Trying to avoid messing around with cutting the tank and welding stuff.

Yeah, it won't work at all. Only possible solution is to reinstall the rotary and awesome 48 IDA.

Doug

well the rotary died : ( else Id be out driving! Right now! This very instant!

---

First Rally: 2010 First RallyX: 2004 (a bunch)
Driver (0), Co-Driver (7)
Organizer (3), Volunteer (3)
Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5)
Last Updated, Apr 9, 2023

Rebuild! </joke>

Quote
Rallymech
I am typing from my phone and I don't know how to post links!

You can search "push-on efi fitting" at Russell Performance, Summit or Jegs.

Some examples: 644110, 640860, 640940.

I preferr the threaded collar types like 644110. They come in different sizes fron 1/4 to 3/8 and adapt mostly to AN-4, -6 and-8 I think. Different colors are available. These fittings are good quality and have saved me lots of time.

Robert are you using the 644110 on the XR fuel rail? I need to make up a -6 line from the chassis hard line to the fuel rail to clear my intake and I was trying to decide between the 644110 and 640860. Will either work? I am guessing the 640860 need fuel line disconnect tools to remove while the 644110 only needs a wrench.

Have you seen the hose ends with the EFI adapters built in? Russell 611250 (straight) and 611270 (90 degree). I am guessing this would allow hose to fit directly on the OEM line without having to use the adapter and a separate hose end.

Quote
Gravity Fed
The stock tank in the Rx7 was arranged with a 3/8 feed line, a 5/16 return line and a 5/16 vent line at the top of the tank.

It's 8mm/7mm/7mm.

I'm using all the stock lines, no problems with the return line being too small, and my pump flows something like 300lph at 42psi.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 2 time(s). Last edit at 03/11/2013 11:50AM by Pete.

Quote
WhiteLX
Robert are you using the 644110 on the XR fuel rail? I need to make up a -6 line decide between the 644110 and 640860. Will either work? I am guessing the 640860 need fuel line disconnect tools to remove while the 644110 only needs a wrench.

That would be nice. I had planned on having a fitting brazed onto the fuel rail but I also remember how many times we had that done on the Audi and it always leaked just a little. We had a rag zip tied on it...
Would be nice also for interchangeability of line between a 4 square or inline intake manifold/injectors.
I may try to find one or order one to test fit...

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Grant Hughes

That would be nice. I had planned on having a fitting brazed onto the fuel rail but I also remember how many times we had that done on the Audi and it always leaked just a little. We had a rag zip tied on it...
Would be nice also for interchangeability of line between a 4 square or inline intake manifold/injectors.
I may try to find one or order one to test fit...

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Grant Hughes