E-Bodies.org Cuda Challenger Forum

Technical Shop => Engine, Transmission & Rear End => Modern Hemi Swaps => Topic started by: JpRngr on July 15, 2018, 03:22:57 PM

Title: Fuel Tank Vent
Post by: JpRngr on July 15, 2018, 03:22:57 PM
So, I'm finishing up my fuel system on my 6.1L swap. I have the Tanks Inc tank with pump and it came with a vent/rollover valve. The directions show that it is to be mounted higher than the fill tube. Problem with that is the Challenger fill tube is high on the fender and the only place higher back there is inside the trunk. Really don't want the vent inside the car for obvious reasons. Any ideas?


Corey
Title: Re: Fuel Tank Vent
Post by: YellowThumper on July 15, 2018, 04:23:09 PM
I believe as long as the line goes up that high it can then have u turn back down and out wherever you choose. Exit doesn't matter. Just the highest point.

Mike.
Title: Re: Fuel Tank Vent
Post by: 303 Mopar on July 15, 2018, 05:03:37 PM
Instead of connecting the check valve, I ran both (yes there are 2 vents on the tank) to the factory vent lines on the passenger rear side that run up the tube in the trunk.
Title: Re: Fuel Tank Vent
Post by: JpRngr on July 15, 2018, 07:10:57 PM
I don't have a vent tube running up the fill tube. I teed the two vents to one with the supplied T, just not sure where to mount the vent. Also, not sure on having the line higher in the middle is a good idea either as it will create a low spot where fuel can collect and possibly block the tube. Directions said not to allow low spots.



Corey
Title: Re: Fuel Tank Vent
Post by: YellowThumper on July 15, 2018, 11:09:03 PM
Yes, later model Challengers don't have the vent tube in fill pipe. That only works with vented cap.
"Low spot" would be a sagging area where fuel can puddle. Thus blocking the tube. How I stated it, it would create the high spot required. Puddling would not occur.
Title: Re: Fuel Tank Vent
Post by: GoodysGotaCuda on July 16, 2018, 02:54:45 AM
I went toward the drivers side wheel well and built a little catch can to stop sloshing from dumping out with the rollover valve on it. It may puddle a little fuel, but it hasn't been a problem.


These are nice, but expensive.
https://www.iimuch.com/collections/fuel-differential-vents/products/fuelvent2
Title: Re: Fuel Tank Vent
Post by: Brads70 on July 16, 2018, 04:21:03 AM
Quote from: 303 Mopar on July 15, 2018, 05:03:37 PM
Instead of connecting the check valve, I ran both (yes there are 2 vents on the tank) to the factory vent lines on the passenger rear side that run up the tube in the trunk.

:iagree:  I did the exact same thing.
Title: Re: Fuel Tank Vent
Post by: JpRngr on July 16, 2018, 08:13:53 PM
Quote from: YellowThumper on July 15, 2018, 11:09:03 PM
Yes, later model Challengers don't have the vent tube in fill pipe. That only works with vented cap.
"Low spot" would be a sagging area where fuel can puddle. Thus blocking the tube. How I stated it, it would create the high spot required. Puddling would not occur.


That would still have a low spot after the high spot due to having to face the vent/rollover valve upwards. It would essentially have an upside down "U" at the high spot, and then have to have a "U" to get the rollover valve to face up correctly. That's what I meant about having a low spot. Or I guess just run a vent with no rollover valve facing down.
Title: Re: Fuel Tank Vent
Post by: 303 Mopar on July 17, 2018, 02:08:33 PM
Quote from: JpRngr on July 16, 2018, 08:13:53 PM
Quote from: YellowThumper on July 15, 2018, 11:09:03 PM
Yes, later model Challengers don't have the vent tube in fill pipe. That only works with vented cap.
"Low spot" would be a sagging area where fuel can puddle. Thus blocking the tube. How I stated it, it would create the high spot required. Puddling would not occur.


That would still have a low spot after the high spot due to having to face the vent/rollover valve upwards. It would essentially have an upside down "U" at the high spot, and then have to have a "U" to get the rollover valve to face up correctly. That's what I meant about having a low spot. Or I guess just run a vent with no rollover valve facing down.

I run without a check valve since the most important thing is properly venting the tank.  I figured if I roll the car, I have bigger issues to worry about.
Title: Re: Fuel Tank Vent
Post by: YellowThumper on July 17, 2018, 03:03:57 PM
Quote from: JpRngr on July 16, 2018, 08:13:53 PM
Quote from: YellowThumper on July 15, 2018, 11:09:03 PM
Yes, later model Challengers don't have the vent tube in fill pipe. That only works with vented cap.
"Low spot" would be a sagging area where fuel can puddle. Thus blocking the tube. How I stated it, it would create the high spot required. Puddling would not occur.


That would still have a low spot after the high spot due to having to face the vent/rollover valve upwards. It would essentially have an upside down "U" at the high spot, and then have to have a "U" to get the rollover valve to face up correctly. That's what I meant about having a low spot. Or I guess just run a vent with no rollover valve facing down.

Agree now with what you are saying. Unfortunately....
Title: Re: Fuel Tank Vent
Post by: Msbaugh440 on July 17, 2018, 05:13:32 PM
I was asking this exact question for my tancs inc setup, I'm glad I'm not the only one. Luckily I have a nipple on my fuel filler tube and I have a vented cap. I think I'll just tee them together and tie it back into there through the trunk.

If I were you I would just look at buying a filler tube with a vent nipple or modifying yours to have one.
Title: Re: Fuel Tank Vent
Post by: Msbaugh440 on July 17, 2018, 05:18:28 PM
By the way it's very important that your cap is vented if you do that, you don't want your tank to pressurize.  I can't ever find vented caps anymore so I just buy the non-vented one and drill a 1/4" hole in it. 

Are you guys talking about that little nipple on the top of the filler tube or are there separate lines I don't know about?
Title: Re: Fuel Tank Vent
Post by: JpRngr on July 17, 2018, 09:46:03 PM
So, I'll probably try calling Tanks Inc next Monday(my next weekday off) and seeing what they suggest. If nothing else, I have extra bulk fuel line that I'll run up next to and higher than the fill tube and then back down and out. Then I'll put some kind of filter on the end instead of the vent/rollover valve they supplied.


Corey