View Full Version : Will this work to vent a gas tank?

10-31-2004, 10:14 AM
I need to vent my gas tank on my 71 firebird. I was going to use a vented cap, but i heard that if you go up a hill, gas can leak out of the cap, so on the back of the tank there are a few ports. i wanted to run a hose out of each port, but what do i put on the end of the hose? i was thinking of a rear end vent. THe little plastic thing that vents your rearend? You can suck in but cant suck out, would that work? or does it need a 2 way vent? i just don't want gas coming out. thanks!

10-31-2004, 11:21 AM
It needs a vent that's open to atmosphere. The easiest and most popular way to do it is to run a line with a couple loops in it (to trap any fuel that gets in it) to a breather of some sort. With the loops in the line, you can run the line down and out the trunk floor.

10-31-2004, 11:35 AM
Matt are you able to post any pictures of what you have explained?


10-31-2004, 05:26 PM
I can't believe I can't find a picture of that on the 'net!! Sorry, but I'm scrambling to leave for SEMA tommorow morning, so no time to look. If you're going to SEMA, I'll draw you a picture. :)

11-01-2004, 12:28 AM
There was somebody that made a tip/roll over valve (which is basically a check valve) that had a barbed end to then attach a hose to run to a vent or canister. But I don't remember who that was. It was only about $20.00 and had a AN-8 fitting on the other side like most all the aftermarket roll over valves.

11-01-2004, 07:02 AM
B. that sounds like the one jp found...it is a marine (boat) part.....I would do a search online, it shouldn't be too tuff to find....

11-01-2004, 08:51 AM
Matt is talking about something like this:


A lot of drag cars don't even put a vent on the end, they just attach it to a bulkhead in the trunk floor.

11-01-2004, 10:27 AM
the loop thing wont' work for me due to packaging constraints and room, i need something that i can put in the end of a hose and call it a day. Also will it create stinky gas smells?

11-01-2004, 10:46 AM
yeah quit eating off of them damn gut wagons and you'll be fine :fart:
why dont you set up your original vapor canister and call that a day! :slap: all i takes is 3 hoses...1 from the tank 1 from the pcv hose and 1 from ported vaccum. biotch

11-01-2004, 11:09 AM
sorry vince, no room for big ole canister tanks and the such. i need some kind of check valve to put on the end of the hose. thanks for nothing bootch.

11-01-2004, 11:09 AM
sorry vince, no room for big ole canister tanks and the such. i need some kind of check valve to put on the end of the hose. thanks for nothing bootch. shouldn' tyou be at the shop?

11-02-2004, 01:13 AM
I can't find the one I'm after. Here's one but it's 1/4" pipe with a barb on the other end. Click here (http://www.kustomtanks.com/) and then on accessories and scroll down. Here's one that may be one like I'm talking about. It's a "Roll over valve, 3/8" in line roll over vent valve, part number FS-RV38" Go here. (http://www.ioportracing.com/Merchant2/merchant.mv?) Here is another one. (http://cmwraceparts.com/FuelSystem/fuel87.html#Rollover%20Valve) Click on the picture of the camera by the description for a good picture. Summit Racing has one, do a search for part number SUM-G3114. Yogi's has one also but it looks like the other 1/4" pipe from above. These valves act like vent valves but also close in the event of a wreck where the car ends up with not all the rubber on the ground. You would need to mount them in a upright position as they are meant to be threaded into the tank but I don't see why they wouldn't work anywhere. Roll over/tip valves are also a requirement for almost any racing organization I can think of. I don't think the looping of the vent line would fly from the above picture if that vehicle was teched.

One of the links didn't work. The one at IO Port Racing Supplies. Go to the drop down menu box at the top right hand side and click on Valves, Pick-ups, Filters, Hoses. It's the 3rd or 4th item down.
As far as the smell, I would think with the car sitting, especially exposed to temperatures that would cause the fuel to vent more there could be some odor. I doubt there would any problem going down the road. The only sure thing for that would be the charcoal can like mentioned above. I would definately keep the vent line to the rear as far as possible or make sure it wasn't tucked up high and somewhat enclosed but I'm sure you know that.

I found some check valves at Godman Hi Perf (http://www.godmanhiperformance.com/index.php?menu=2&cat=check%20valves) but they don't give any info. They may just be good for a fluid check valve. Might call them.

11-02-2004, 01:14 AM
double post