Fuel Cell Maintenance

Fuel cells – not the hydrogen-oxygen electricity generating things that the EPA is excited about, but the impact-absorbing fuel tanks in racecars – are an important safety item. Unfortunately, they’re expensive and have a finite life span. Foam baffling inside keeps the fuel from sloshing and reduces the possibility of explosion in case the cell is ruptured, but the foam deteriorates after a few years and turns into a fuel pump-clogging sludge that causes racecars to choke to a stop. The bladder that actually holds the fuel typically lasts about ten years before it begins to crack and fall apart. Owners of older cars with older fuel cells dread the day when they find a puddle of fuel under the car.

The cheap and easy part of fuel cell maintenance is the replacement of the foam baffling. The foam only costs between $50 and $200 (depending on the fuel cell size). Having old foam break up can cost fuel filters, fuel pumps, and lost races. In the last two seasons, two of my friends lost a combined 6 races due to fuel cell foam clogging.

I found some interesting information from Eagle Fuel Cells (Eagle River, Wisconsin) about extending the life of fuel cells. Storing the cell empty is bad (oops), because that allows the rubber in the bladder to dry out. Regular pump gasoline is also bad, because it is not as stable as aviation gas, and the formulation is particularly harsh on the rubber ("gasohol" is even worse). I don’t know if race gas counts as pump gas, but AvGas is cheap enough that five gallons for winter storage will be worth the investment if it delays the replacement of the cell for another year.

Someone (sorry, I don’t remember who) recently pointed out that the rubber in the cell bladder doesn’t get along with water either. Cars where the cell sits on the floorpan often trap rainwater between the floor and the cell if there is no provision for drainage. Tiga were clever enough to sit the cell on top of some frame tubes, which minimizes contact with water. That’s what we call “good news.” The bad news is that resting the weight of the cell (and the fuel inside) on such a small area causes a major strain on the bladder. Fixing this should also be inexpensive and easy. A “floor” of heavy wire mesh between the cell and the tubes will at least spread the load a bit without trapping any water against the bladder. A basic frame around the mesh should make it rigid enough that the load will be much more evenly distributed.

All three projects should total about $150 and maybe a weekend. That’s a bargain if it keeps the cell alive through another season.