Please break me off some knowledge concerning fuel cells...

I want to install a fuel cell in the the 2011 Challenge VivaFestiva as the stock tank leaks and a cell should be cheaper to buy used. And since I have never bought one I am looking for some info.

I seem to think that a 8 gal (or so) will work well as far size but questions are as follows.

Foam or no foam?

What about a fuel pump? I am going from a carbed motor to a FI one so therefore I believe that a in-tank pump will be needed. Will a cell accommodate that?

Fuel level sender. I know that many come wired with a GM style float but can these be made to work the stock cluster gauge or will a separate gauge be needed?

Anybody know the rules as far as mounting in a hatch? I also plan on having a battery box back there too. I tried viewing the NHRA rules but it appears to be that you have to be a member to read the rule book or purchase it separately. I'm not sure what the rules are on having two things that can go boom next to each other.

That's all the questions I have for the moment.

Thanks!

For the fuel pump, I recommend the high pressure (only) pump from a Ford F150 truck or van. You don't need the low pressure (back) pump. This is an external pump and you can mount it anywhere you want. Put a fuel filter before and after the pump.

Foam is to keep the fuel from sloshing around, or minimize it anyway. If you have foam, you can't use a conventional float type fuel level sender. You can get some adapter thingies that go on the side, but at added cost to your project. If it works or not with your cluster gauge would depend on what the gauge is expecting now.

If I recall, most rules say that any battery box mounted in the passenger compartment has to be sealed and have a vent hose going outside the passenger compartment. Of course, you'll need to look at whatever rule book you're building to.

I'm running an RCi 8 gallon cell in the Jensenator, with an external pump. Like this one:

only mine has 2 fittings at the top instead of 1. One is the return from the fuel rail, the other is the vent fitting with the rollover valve etc. There's 2 outlet fittings, I capped one. They are #8 fittings, more than enough for even big engines.

I wouldn't do an internal pump, the baffling would be tough to build. The thing to remember is the pump must be below the cell or it will starve, particularly on hard acceleratation. If the fuel lines have to rise to go over the rear axle, the pump must be between the cell and the rise of the lines.

Like Doc H says, foam is there to keep the fuel from sloshing around and getting away from the pickup. I have foam in my cell, alcohol fuel (such as 10% pump gas) plays hell with that stuff. Be prepared to replace it every so often.

Even with foam, high G loading can present problems. I run a minimum of ~2 gallons in my cell for that reason and it's usually half full. (I use an 8 gallon due to a lack of vertical space.) If you want to cut weight, get one of those 3-4 gallon vertical cells, that will cut the slosh problem down a lot.

Level sender? My fuel level sender is a piece of aluminum angle (don't want any sparks now do we?) and it connects to my eyeballs.

Speedway has several, too. Prices are pretty reasonable. A couple of theirs have a sump for fuel pickup. Keep level above the sump and you'd be okay for some high-g stuff. Severe, constant g's may need the vertically oriented cell that Jaz sells.

For any sort of road racing or hillclimbs, those plastic cells will need a sheetmetal enclosure. ATL has super-saver cells that are also rotomolded and have the appropriate SFI/FIA approvals for rally/road racing/hillclimbs.

Thanks for all the replies. This gives me some points to consider when shopping now.

Thanks Doc for the info on the F150 pump also. That is exactly what I need - without the high price of a after market one.

You can do a search on E2000 and that's a similar pump, used in many conversions.

If this car might go on to race w/ NASA it needs to be an FIA FT3 rated cell - even if you choose a class with no requirements for a cell at all. If it has one - it has to comply. The cheapest one I could find was $600. I went with a stock junkyard tank instead.

The plastic cells have to have a metal baffle between the driver and the cell, in my case the Jensenator has a sheet metal bulkhead which meets the letter of the rules. If the cell is inside the passenger compartment (such as in the hatch area of a hatchback), it gets much more complicated. So like GPS says, go with a stock tank in that case. But- it too must have a metal baffle between the driver compartment and the cell.

Out of curiosity, does anyone know if the JEG's etc metal cells meet SCCA?

Like these: