[punkin]

Hello all,

Initially I posted in the 67-69 Firebird section thinking my question was a bit more vechicle specific but I haven't had any responses yet. Apologies for the double postings.

I have a 68 firebird. Purchased a Rick's tank for EFI and have installed a Sniper Xflow efi system. I was hoping that the vented gas cap would be sufficient to vent the tank but it's only a one-way vent as far as I can tell.

I have an extra port on the top of the tank for a vent line. Everything I've read is that the vent line should be at least as high or higher than the fill port. I've read in some other forums where guys are running vents up high inside the trunk but I'm not convinced this is a good idea.

I'm open to suggestions and if you're using a vent with a check ball or baffle of some kind I would really like to know what you're using.

Thanks very much for taking the time to read through this.

[tom s]

The cap vents in but not out.I drilled a small hole in my cap I use when the car sits but if I drive with it fuel leaks out.Tom

[JLMounce]

I use the vents on my Tanks Inc tank (1 on the tank, 1 on the pump hat) and tie into the factory vent that is indeed above the fill port. I have not had any issues with this setup.

[krisr]

You can run the vent line up above the rear end and coil the line a few times then point it back down. If the vent line is up the front of the tank the only time it "may" get fuel go into the line is when you're hard on the brakes

[punkin]

Originally Posted by JLMounce

I use the vents on my Tanks Inc tank (1 on the tank, 1 on the pump hat) and tie into the factory vent that is indeed above the fill port. I have not had any issues with this setup.

Thanks Jason, if I'm not mistaken, the 69 has a vent tube built into the filler neck doesn't it? Is that where you're taking yours? If so, unfortunately, the 68 doesn't have this. I've heard of guys welding or brazing in an additional tube into the filler neck. I'm toying with that idea as well.

[punkin]

Originally Posted by krisr

You can run the vent line up above the rear end and coil the line a few times then point it back down. If the vent line is up the front of the tank the only time it "may" get fuel go into the line is when you're hard on the brakes

One thing I'm concerned about with the looping of line is if fuel does get up in there, wouldn't that create a vapor lock much like a p-trap in a sink drain and then defeat the vent? Maybe I'm not imagining what you're describing correctly.

[JLMounce]

Originally Posted by punkin

Thanks Jason, if I'm not mistaken, the 69 has a vent tube built into the filler neck doesn't it? Is that where you're taking yours? If so, unfortunately, the 68 doesn't have this. I've heard of guys welding or brazing in an additional tube into the filler neck. I'm toying with that idea as well.

Ah yes I always forget the is a 69 option. Yes there was a vent in the filler neck that goes up and loops out near the top of the license plate.

Other things I've seen people do is get a rollover vent and mount it near the top of the axle or mounted to the underside of the trunk pan. It just needs to be higher than the top of the tank. The rollover vents are a good safety device and aren't too expensive.

[punkin]

I thank you.

[punkin]

Originally Posted by tom s

The cap vents in but not out.I drilled a small hole in my cap I use when the car sits but if I drive with it fuel leaks out.Tom

Not to dismiss, in a pinch this could work but...I would like to avoid wiping the bumper down after a field trip. I've got a pretty steep drive-way too.

[tom s]

I have 2 caps,keep the one with a hole in a zip lock bag.Tom

[Squidward]

I did a retro in tank pump conversion. The pump flange had 3 6an fittings: Fuel out, fuel return, and vent. Fuel out and return went to an efi return regulator mounted just in front of the tank. I run the regulator outlet to the factory 3/8 line that I flared for 6an/JIC fittings, which I also did up at the front end of the line at the k member. It makes for a clean single line plumbing to the throttle body.

I ran rubber fuel hose and a fuel filter to the tank's vent connection. The fuel filter filters the vent air. It sits up in that void between the trunk pan and differential, higher than the tank, but most certainly not quite as high as the fuel filler cap. No problems.

[mysticmissle]

anyu pictures and parts that you may have used squidward? thanks this sounds like a clean set up to use with my tunnel ram sniper set up

[Squidward]

Originally Posted by mysticmissle

anyu pictures and parts that you may have used squidward? thanks this sounds like a clean set up to use with my tunnel ram sniper set up

I will get some in the morning. I spent all day Wednesday in my dress up clothes before I went to work, so crawling under car was a no-go.

I enjoy the simplicity of the setup I used with the return regulator. Others prefer to run the full supply to the throttle body, and run a full return line back to the tank. I liked the idea that GM used with its Corvette fuel filter/regulator, which did the same thing. I've not noticed any issues with fuel heating, vapor lock, etc. But with 60 psi fuel pressure for EFI, it would have to be pretty toasty to reach a saturation point, like maybe 140F?

I used this:
https://fitechefi.com/product/50014-...600-hp-module/

But truth be told, one might consider a new tank ready for an in-tank pump. I had to fight a little with the ribbing on my stock tank. And then there was the issue of emptying and cleaning out an old tank, and welding closed a couple of holes/cracks. In hindsight, maybe a Tanks inc or other vendor's kit. The Fitech retro pump kit is good for as shallow as 6", which is about all you get on a stock first gen tank. IIRC, my pump depth ended up at about 6.5".

Many of the aftermarket efi tank kits have NPT fittings, requiring adapters to get to AN fittings. I liked that the Fitech was all AN for the ins and outs.

I used my stock fuel level sender, which doesn't work anymore. So I will be dropping my tank again to replace that.

If I had to do it again, I would be 50-50 on EFI ready tank, or retrofitting. At the very least, I'd start with a new stock tank, new fuel level sender, and the Fitech retro pump kit.

Regulator:
https://www.tanksinc.com/index.cfm/p...BoCjFIQAvD_BwE

I have a pressure gauge back on the regulator, and I have one in line up front that gives a final fuel pressure. I also have a final 6an fuel filter at the gauge, can't remember the maker, or if it is 10 or 25 micron.

[Squidward]

Originally Posted by mysticmissle

anyu pictures and parts that you may have used squidward? thanks this sounds like a clean set up to use with my tunnel ram sniper set up

Correction, no gauge on the regulator, just up front.

Bad pics, but I think you can tell.