Has anyone heard about running dual fuel tanks? The main tank would be pump gas then a smaller fuel cell would be race/high octane gas. They could both run into one of the fuel transfer switches with a external fuel pump after that. This would let you run with one pump which could suck from either thank.

Thanks,
Chris

 

How would you do a return line? Would you switch that too? Returnless fuel system maby?

Sounds like an easy way to complicate an uncomplicated problem. I wouldnt trust a system like that because how would u know when the low(er) octane fuel is out of the lines and cleared the injectors?

 

Return line would be setup the same. That is true it would make it complicated... maybe too complicated. If you were to drain your tank and put higher octane in it would probably take just as long to burn off the excess fuel in the lines.

 

Some Supra guys played with that, and they abandoned the idea...

 

Some Supra guys played with that, and they abandoned the idea... I'd go water injection instead.

 

I'm not real knowledgeable on this, but i'll ask anyway: could one use a fuel tank/fuel cell combo?

 

go look at alot of older(80's)fords in junk yards. alot of those had dual gas tanks at the flip of a switch form within the interior. one of my friends late 80s econoline vans had a 18 and 22 gallon tank under it that all you had to do was flip a switch to go from empty to full.

 

Yeah a fuel cell is just another means of holding fuel, like a 2nd metal tank. Except a fuel cell is designed better to where it is safer in extreme conditions. Some fuel cells also have a sump built in which would eliminate any need for welding in a sump.

Crusader, pretty much what I was thinking of.... but the fords (I think) use two pumps then go to the switch. I would be using an external pump after the switch... I wonder if that would put too much suction on the switch causing it to be unreliable.

 

why not just mix the race gas into the regular gas tank,saving the trouble and the weight?

 

Kevin T. Wyum ran this type setup in his car. PM him, maybe you can get some info from him. This is what I know......

"Two different tanks. There's a 10 gallon fuel cell in the spare tire area. There's a big SX pump for the race cell and a cosmo in the stock tank. So one switch controls which pump is on with check valves to prevent backflow before a Y junction. Then there's a servo controlled switch that changes the return line route. I have that on a seperate switch so I can purge lines and send fuel back to either tank for whatever reason."

Kevin T. Wyum


Maybe that will help you some
STEPHEN

 

Oh, I'm retarded.

My truck has two fuel tanks, a ~16gal and an ~18 gal. There's a switch in the cockpit. I'm pretty sure there are two fuel pumps, because the front one doesn't work now.

Now, it's running 8 injectors and I think the total volume of the injectors is less than, say, my 680/1680 setup, but it takes about two seconds for the fuel to completely switch over from one tank to the other. If you hit the switch and go to the front tank, it will run for two or three seconds and then die (no front FP = no fuel).

edit: Did I just say "cockpit"?

 

change the switching valve, they go bad all the time. They way I remember the trucks(and it's probably wrong), they have a single giant external Bosch pump that feeds off both tanks, and the switch on the dash runs the aforementioned POS switching valve.

 

really? i couldn't be sure, either way...need to buy a haynes manual and inspect.

but it's got 244k so a fuel pump crapping out at this point is acceptable