RCR40 Fuel Cell Foam

Things to consider..
Quote Pegasus racing: Fuel cell foam reduces fuel sloshing and minimizing the chance of explosions, but it does deteriorate over time. As the foam breaks down, it can quickly clog fuel filters, fuel pumps, and carburetors. We recommend replacing fuel cell foam baffling at least every three years.

Second, modern fuels contain % ethanol (at least in Europe). Not every foam can handle that.

I had my Alloy tanks custom made at a local welding shop with baffles.
 

PaulProe

Supporter
In a recent conversation with Chuck S on this, I learned he had followed the suggestion of adding the foam blocks to his RCR tanks. The results were 'less than stellar'. He said it doesn't stop the fuel slosh.

Maybe he'll chime in and add his experience.

I am considering adding baffles to mine, once I receive them. Don't really like having to weld on the tanks but it seems to be the only true solution.

Paul
 

Randy Folsom

Supporter
In a recent conversation with Chuck S on this, I learned he had followed the suggestion of adding the foam blocks to his RCR tanks. The results were 'less than stellar'. He said it doesn't stop the fuel slosh.

Maybe he'll chime in and add his experience.

I am considering adding baffles to mine, once I receive them. Don't really like having to weld on the tanks but it seems to be the only true solution.

Paul
Paul, If the Wiffle balls don’t work I too will open up the tanks and install baffles. In that case, I will go with a professional welder which probably won’t cost much more than foam. Cheers, Randy.
 

Randy Folsom

Supporter
By the way, there are swirl pot systems which are part of/i.e. inside the fuel tank.
Walter, I have been thinking the same. It seems to me that a baffle just forward of the fuel pickup is essentially a swirl pot. In my Cobra replica’s Mustang fuel tank, there is a ‘pot’ that the fuel pickup sits in. I am guessing it works since I have never heard about the need for external swirl pots on Cobra’s to address fuel sloshing from side to side when cornering. However, because the GT40’s have two tanks, an external swirl tank is still a convenient way to join the systems. Cheers, Randy
 

Randy Folsom

Supporter
I wonder that if sloshing can be well managed then it might be possible to use fuel level to determine if a pump is powered. My thinking is to run the pumps in both tanks continuously by default. But if the fuel level drops to certain level, then automatically disable that pump. I envision using a comparator board with an Arduino to make sure the fuel level is truly low, and not just the result of sloshing. The tank pumps would feed a swirl pot with return lines.

With this approach, I could fill one or both tanks and not worry about any switching, or cross tank flow systems.

Thoughts?
 
Walter, I have been thinking the same. It seems to me that a baffle just forward of the fuel pickup is essentially a swirl pot. In my Cobra replica’s Mustang fuel tank, there is a ‘pot’ that the fuel pickup sits in. I am guessing it works since I have never heard about the need for external swirl pots on Cobra’s to address fuel sloshing from side to side when cornering. However, because the GT40’s have two tanks, an external swirl tank is still a convenient way to join the systems. Cheers, Randy
Hi Randy: Here is a screenshot from Jansen Competition's catalogue (in German) making reference to internal catch tanks by RTL. Of course, you'd need one each.
I use 2 separate tanks for fuel supply to an external swirl pot (with some safety features recommended by Kinsler), a magnetic switch linked to the scavenge pumps for surplus fuel return into the proper tank (see my build log). Before engine start, I first turn on the scavenge pump of choice from a 3-way switch (this way I cannot run both pumps simultaneously which would likely blow the fuel fuse - as it did in the state I bought the car). I wait till the catch tank is filled and then I turn on the injection pump (using a separate fused relay circuit!). I tend to empty the driver's side tank first, then that of the passenger side - better weight balance - haha. I also heat-shielded the key fuel lines.
I highly recommend using fuel cells (one of the features I much liked on my car when I bought it). They last a lot longer than the FIA expiration date. Even if you ``just" build a street car, a GT40 which could not be taken on a race track makes little sense, does it?
Best regards and joy with your project!!!
 

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