Fuel cell design - running lines from trunk to engine bay

[Mick]

The cell is a FuleSafe Enduro which comes with the Radium surge tank pre-installed. Radium used to sell these cells with their own branding but stopped and now tell you to buy direct from FuelSafe. I opted for the 12 gallon, 0-90 ohm fuel level sender, and Walboro 3950 (F90000274) for the lift and surge pumps. The 3950 was the only pump they had in stock but it was fine with me.

I chose it because it had everything integrated, it's fully encased, and Radium made the spare tire well mounting brackets for it. Between the cell and mounting it was on the expensive side but seemed worth it. The result is tidy and it saved time trying to fab a case/mount.

[1990m3]

beautiful work Mick -- when do you get to go and test it out for the first time?

[Mick]

Thanks. I have a test day in a couple of weeks. If I'm still posting after that you'll know I didn't die a fiery death

[Mick]

One side effect of the fuel cell that I hadn't considered is the vent is always open, making my shop constantly stink of fuel vapor.

Anyone have ideas to seal off the vent when the car is in storage? The ideal would be some sort of valve that would let air flow in either direction but only when it's over a few PSI, just enough to not have it be constantly open. Otherwise I could put a ball valve in the line, but I know I'll forget to open it one track day. I'd much rather have something I don't have to think about.

[jimmy p.]

I dont mind the smell,,, smells like Victory!

Mine exits via a -6 bulkhead fitting through my spare tire well.
I have a -6 cap that I put over it when I weld in there. That cap has a 7" long fluorescent pink gaffer tape tail on it so that there is no way I can ever forget to take it off.

[Ironhead]

One side effect of the fuel cell that I hadn't considered is the vent is always open, making my shop constantly stink of fuel vapor.

Anyone have ideas to seal off the vent when the car is in storage? The ideal would be some sort of valve that would let air flow in either direction but only when it's over a few PSI, just enough to not have it be constantly open. Otherwise I could put a ball valve in the line, but I know I'll forget to open it one track day. I'd much rather have something I don't have to think about.

I have your solution Mick.

If you plumb one of these into the vent line:

https://www.iimuch.com/

Basically you run the vent hose through the II Much canister, and it removes pretty much 100% of fuel odor from the vent. My car with fuel cell sits in a closed garage year round, and I cannot even detect fuel odor.

I will caution you, I believe they are the only place that make something like this, at least they act that way. When I ordered I found them to be kind of arrogant about it. They took payment in full and didn't deliver the device for several weeks. When I inquired about the delay their response was basically "you'll get it when you get it". That was a few years ago, might no longer be the case, so just a heads up.

[Mick]

Thanks for that, it looks like the solution. About how large/heavy is it? They don't list dimensions on the website.

Man I hate companies that act like they're doing you a favor by selling you their product. I couldn't find any 3rd party vendors, Summit has the bulkhead version but I'll want the one with orb fittings

[Ironhead]

About how large/heavy is it?

About the size/weight of a full can of beer.

[Mick]

Before I go down the route of installing a vapor canister I want to consider using an inline check valve.

Does anyone see an issue with installing this check valve in the vent line just before the breather filter?

https://www.amazon.com/dp/B09TT4BVB5

It seems like the perfect solution but I want to make sure I'm not missing something obvious. The only difference I can see from an open vent is that the tank would build pressure at rest, especially on hot days when the car is sitting in the sun. I can't imagine it would be much though, no more than a fuel jug would build up, maybe 8psi.

I don't think it will be an issue if I run the car with pressure in the tank, it seems like it would equalize as the fuel is depleted and then begin to inhale though the breather as it creates vacuum.

The only downside I can think of is that an unexpected pressure release when opening the fill cap could be dangerous, which isn't really an issue on a track car as you'd know to expect it.

I hesitate to do it because I feel like I'm missing something or this would be a common solution.

[Ironhead]

The idea of the cell and related plumbing pressurizing itself without an exit vent doesn't really sit well with me, although I can't put my finger on exactly why.... I know that the fuel system plumbing is designed to withstand a measure of pressure, but the cell itself really is not. I would suspect that leaks....perhaps just vapor.....around the fill plate would be a likely outcome.

I know every car I have ever seen, be it production or racing, has a two way vent for the fuel tank. I think your hesitation is well placed. There are bound to be reasons.

[Mick]

I spoke with Chris at VSR and although he had no direct experience on a track car he did have a boat tank that had only a check valve. He said it was surprising just how much pressure would build. It would blow up like a balloon on hot days, so much so that fuel would weep from fittings.

I also called FuelSafe, who makes the tank, they were reluctant to answer and kicked me over to RadiumAuto who makes the surge tank. Radium couldn't give me a specific reason not to do it but advised against it.

Given that, and your feedback Ironhead, I'm going with the II Much canister. Thanks for kicking the idea around with me.

[Yahweh]

Take a look at roll over valves / discrimatator valves, then run the vent to the exterior of the car.

Needs to be properly sized as if its too small its get stuck in the closed postion from bouncing, or slosh of fuel.

And technically this is where most the air would be venting on fill up, So make it as big as your want to let air out on fill up.

Alot of rule books are also now requiring discrimator valves.