Multi Fuel Tank Questions......

Gentlemen,
First let me say I don’t have a GT40 ,,, but a Factory Five GTM,,,, but the similarities between the two are evident,,, and I do love the GT40. That said,,, I need to ask about fuel tanks/cells. My car is based on a C5 Corvette and with that has two fuel tanks that sit right behind the driver and passenger. The space allotted for these tanks is very tight and I’d rather switch to fuel cells as there may be a track day in my future. So my questions: When running multiple fuel tanks,, how do you balance the fuel loads,, is it just a crossover pipe attached low in both tanks? If so,, do these present problems when a bladder is introduced? In this configuration,,, do you fill one and run from the other???

As an alternative,,, anyone running separate tanks, pumps, gauges etc??? Are there other ways I’m not thinking of???? If it matters,, I’m running an FI LS1 with high pressure lines.

Any insight (and of course pictures) would be greatly appreciated!!!!

Best Regards,
Fred

Hi Fred,

As far as I know most if not all cars run two completely separate tanks with a filler cap for each. Even on E.F.I cars you will take and return fuel back to the same tank to avoid the inevitable overfilling situation. On my car I just run a carb and so each tank feeds a shutoff valve, into a filter, into a LP Pump and then both to a 'T' piece and up to the carb. Like most 40's - I simply throw a switch on the dash to decide which tank to use and this opens the valve and starts the pump. Obviously efi will be alot more complex - but they are setup so when you switch from tank to tank everything swaps over.

The GTM is a nice car. I'm looking forward to seeing some on the road pretty soon - there's one being built a couple miles from my house.

First of all, if you can go with a single fuel cell instead of two tanks then, by all means, do it. It would be race-worthy, safer, less complicated and probably cheaper than a two pump setup.

The fuel system on my car uses two tanks and a swirl pot. Low pressure pumps for each tank tee into the swirl pot inlet. The swirl pot has two outlets - to the high-pressure pump and to a 3-way valve. The other side of the 3-way valve are returns to the two tanks. The swirl pot remains full and eliminates fuel surge from vehicle acceleration. The left or right pump can be selected as the fuel source from the cockpit. There are solenoid valves in front of the LP pumps - these solenoids close upon pump shutdown to prevent fuel backflow through the system.

An alternative would be to use a 6-way valve.

Another alternative would be the fuel control valve that forum member Ron Moreck offers. It is described in this thread

Fred,
Try ATL. They probably have a cell for the corvette and if not they will make anything. I remember seeing a cell for a GTP car with an integral crossover between the two cells. If they have something that fits, they should have the appropriate hardware and pumps to get it working.
Bill

Gentlemen,
Thanks for your thoughts. I spent the last few days reviewing things a bit more and it does seems separate tanks are the norm. Apparently some of the Ultima owners do tie the tanks together although I gather the factory doesn’t recommend it. In the case of the GTM,,, the tanks are maybe 18” apart so the run between them is not all that far,, but there would be quite a mess if something went wrong.

I do have an additional question if I might. The Ultima’s are set up with a connection that ties the top of the tanks together,,, this way if one tank is overfilled it will spill into the other. Do the GT40’s run something similar? If not,,, what happens in an over fill situation?? What is the typical tank capacity of a GT40??

Again,, many thanks for your thoughts!

Best regards,