Improve venting for OEM tank

[turbogrill]

Hi,

 

We are currently using the stock fuel system, it works great but filling the last 1-2 gallons take a long time and usually ends up in spilling and some added stress to the pit stop.

 

The OEM system has the vent going back into the filler tube. My plan is to remove the OEM vent and replace it with a hose and a discriminator valve. 

 

I plan on reusing the existing vent outlet from the tank.

 

 

 

1. Is the radium valves are only for intank usage? They look like this:

http://www.radiumauto.com/Dynamic-Safety-Vent-DSV-Valves-P1508.aspx

 

I assume I would need something like this:

 

https://www.pegasusautoracing.com/productdetails.asp?RecID=7265

(Also why is it $200! 

 

2. Can I terminate the vent hose inside the trunk as high as possible? 

 

3. The rules only require a roll over valve, but I guess that wouldn't work well in my application since the filler tube and vent will be similar height?

So during fill it's likely that it will dump gasoline out the vent. Maybe that works better if you can have the vent in the roof? (If you are racing a station wagon)

 

 

 

 

Edited June 22, 2021 by turbogrill

[wvumtnbkr]

I'm not quite sure I understand the entire issue, but can't you put the discriminatory valve right at the tank and then have the vent hose after the valve?  Instead of putting the d valve at the end?

[petawawarace]

5 hours ago, turbogrill said:

Hi,

 

We are currently using the stock fuel system, it works great but filling the last 1-2 gallons take a long time and usually ends up in spilling and some added stress to the pit stop.

 

The OEM system has the vent going back into the filler tube. My plan is to remove the OEM vent and replace it with a hose and a discriminator valve. 

 

I plan on reusing the existing vent outlet from the tank.

 

 

 

1. Is the radium valves are only for intank usage? They look like this:

http://www.radiumauto.com/Dynamic-Safety-Vent-DSV-Valves-P1508.aspx

 

I assume I would need something like this:

 

https://www.pegasusautoracing.com/productdetails.asp?RecID=7265

(Also why is it $200! 

 

2. Can I terminate the vent hose inside the trunk as high as possible? 

 

3. The rules only require a roll over valve, but I guess that wouldn't work well in my application since the filler tube and vent will be similar height?

So during fill it's likely that it will dump gasoline out the vent. Maybe that works better if you can have the vent in the roof? (If you are racing a station wagon)

 

 

 

 

I'm guessing that your issue is with where the location of the vent is in the stock tank. Changing to a discriminator valve and moving the vent termination point may not help you at all.

 

Where is the fuel spilling from?

[TiredBirds]

not sure how that would help...it might be better to use a larger vent tube. 

[turbogrill]

 

 

1 hour ago, wvumtnbkr said:

I'm not quite sure I understand the entire issue, but can't you put the discriminatory valve right at the tank and then have the vent hose after the valve?  Instead of putting the d valve at the end?

 

Yes! That makes more sense. 

29 minutes ago, petawawarace said:

I'm guessing that your issue is with where the location of the vent is in the stock tank. Changing to a discriminator valve and moving the vent termination point may not help you at all.

 

Where is the fuel spilling from?

 

It spills from the main fill out on the ground  (via my fancy spill-pickup so all ends up in a large pan under the car, so don't worry about that).

 

The vent sits on the top, I don't think it could be moved higher up.

 

34 minutes ago, TiredBirds said:

not sure how that would help...it might be better to use a larger vent tube. 

 

yes, will do. The current vent line is being reduced from a small to a tiny line. 

[Team Infiniti]

1 hour ago, turbogrill said:

The vent sits on the top, I don't think it could be moved higher up.

If your vent tube separates from the tank you may find it mounted up top but angles down inside the tank leaving addl unused airspace.

 

We have a T in the stock vent tube hooked up to a shop air hose female disconnect to add another vent during fueling.

[turbogrill]

37 minutes ago, Team Infiniti said:

If your vent tube separates from the tank you may find it mounted up top but angles down inside the tank leaving addl unused airspace.

 

We have a T in the stock vent tube hooked up to a shop air hose female disconnect to add another vent during fueling.

 

But they share the same tube going into the tank? So you essentially just made your venting tube larger? 

[wvumtnbkr]

1 minute ago, turbogrill said:

 

But they share the same tube going into the tank? So you essentially just made your venting tube larger? 

I believe Eds system allows for air to enter a different place than the filler neck.  In other words, if gasoline gets near the vent in the filler neck, it will still "exhaust" air out of the tee in his system.

[turbogrill]

2 minutes ago, wvumtnbkr said:

I believe Eds system allows for air to enter a different place than the filler neck.  In other words, if gasoline gets near the vent in the filler neck, it will still "exhaust" air out of the tee in his system.

 

Got it!

 

And does the extra vent has a valve on it?

[Team Infiniti]

13 minutes ago, turbogrill said:

 

But they share the same tube going into the tank? So you essentially just made your venting tube larger? 

I would not describe it as such, wvumtnbkr has it nailed

10 minutes ago, wvumtnbkr said:

I believe Eds system allows for air to enter a different place than the filler neck.  In other words, if gasoline gets near the vent in the filler neck, it will still "exhaust" air out of the tee in his system.

This, if you want to see it we will be @ CMP

 

7 minutes ago, turbogrill said:

 

Got it!

 

And does the extra vent has a valve on it?

Female air chuck is the self sealing valve, otherwise the vent is plumbed stock.

Edited June 22, 2021 by Team Infiniti

[wvumtnbkr]

Probably not in his case.  Since he is using an air fitting, it should be closed unless connected during fueling.  Like a quick disconnect.

 

I'm not sure I would personally go that route without fully understanding what is going on.

 

I would be checking to see if something else is going on with the system.

 

A good way to do that is to disconnect that vent from your filler tube and extend it outside of the car.  Fuel the car and see if it still struggles on the last gallon or 2.  If so, it might mean you need a bigger vent, or a higher vent, or something else is going on.

 

With my car, there was some corrugated hose for the filler from the factory.  This was causing splashback.  I changed it to a smooth I.D. hose and haven't had the issue since.

Edited June 22, 2021 by wvumtnbkr

[turbogrill]

thanks! I will go a head and investigate