Ford boys, fuel tank questions

[Vimes]

Wasn't sure where to put this, so thought it would work here.

One of the problems with my project has been, where to stick the fuel tank? I happened across a link that showed that Mercedes uses a saddle tank, and further research shows that 2015+ Mustangs have a 16 gallon saddle tank that rides over the driveshaft. I think this will solve my biggest problems with a tank.

SO, the questions are, have any issues with the tanks working correctly? I understand there's several methods for transferring fuel from one side of the saddle to the other. Also, any issues with higher pressure/volume fuel pumps? Figuring it'll be a lot easier to get a high pressure/volume pump for a Mustang than a Mercedes as well. I'd like to know if there are any inherent problems with this possible solution. I'd already planned on cutting an access port in the bed of my truck for pump access so cutting two access ports would not be a problem. I also already planned on doing a driveshaft loop.

[capri v8 driver]

SO, the questions are, have any issues with the tanks working correctly? I understand there's several methods for transferring fuel from one side of the saddle to the other.

You don't need a high pressure pump for the transfer function. The saddle tank like the Ford, Jaguar or Mercedes are actually 2 tanks where the first tank gets filled (topped off) by the second tank and keeps doing it till the 2e tank is empty. Ford and Jaguar use a vacuum system to draw fuel out of the second tank for most of there saddle tanks. Only in high HP applications they use a small fuel pump to transfer the fuel to the fitst tank that runs constantly till the 2e tank is empty.

Your problem wil be the measurement of the fuel level as you have 2 fuel tanks where first the second tank fuel level wil go from full to half full en the first tank fuel level that goes from half full to empty. That's why you have 2 fuel level sensors in the tank. Normally the conversion from 2 fuel level signals to 1 signal for the gauge is done by a ecu or a signal processor. I havent seen a aftermarket fuel gauge that can handle this. Its doesn't mean they don't exist.

[Vimes]

Good deal. The gauge isn't a concern, comes to it I can just use two. I'm mainly concerned with how reliable the setup is over the long term. I know that no fuel pump lasts forever, but if they're only lasting 50K miles or so I'd likely keep looking for a different solution.

[capri v8 driver]

I'm mainly concerned with how reliable the setup is over the long term. I know that no fuel pump lasts forever, but if they're only lasting 50K miles or so

The main reason the transfer system fails is mostly due to leaks and dirt. My S type did 271k before i got rid off it. Except for 2 main fuel pumps I never had a issue with the fuel tank or the transfer system.

[Vimes]

Sweet. Putting this on the list then. Tank will be under the bed, so a couple of fuel pump hatches will be easy to do. This also lets me keep the spare in the stock location as well. Thanks, appreciate it!

[Vimes]

Well, update, of sorts - a saddle tank won't work. What with the configuration being a crewcab bed behind the extended cab, there's not nearly enough room behind the cab, in front of the rear diff and under the bed to fit on. I'm also going to have to raise the transmission tunnel front to back to clear the driveshaft. I'll have to figure something else out once the truck comes home.

[capri v8 driver]

I saw this a bid late. Looking at your project it looks there is room for a fuel tank behind the rear diff.

With a aftermarket ECU and cluster gauges you don't need a saddle tank. But with the Challenger gauge cluster you need to go with a saddle tank or build a tank with 2 fuel level sensors where 1 fuel level sensor measures from full to half full en the second fuel level that measures from half full to empty. Or use some kind signal processor that can convert fuel level 2 signals into 1 signal.

That's how i solved the fuel level issue when i did a Jaguar engine/trans swap with the stock electronics in my Ford 20M witch has a normal fuel tank. To be honest, I had to re-use everything from the Jag's electronics to make it work and to keep the ECU/controllers happy. That part of the build took me 2 years. If i have to do the electronics again I would buy a aftermarket ECU for the engine and trans and call it done.

[Vimes]

I saw this a bid late. Looking at your project it looks there is room for a fuel tank behind the rear diff.

With a aftermarket ECU and cluster gauges you don't need a saddle tank. But with the Challenger gauge cluster you need to go with a saddle tank or build a tank with 2 fuel level sensors where 1 fuel level sensor measures from full to half full en the second fuel level that measures from half full to empty. Or use some kind signal processor that can convert fuel level 2 signals into 1 signal.



That's how i solved the fuel level issue when i did a Jaguar engine/trans swap with the stock electronics in my Ford 20M witch has a normal fuel tank. To be honest, I had to re-use everything from the Jag's electronics to make it work and to keep the ECU/controllers happy. That part of the build took me 2 years. If i have to do the electronics again I would buy a aftermarket ECU for the engine and trans and call it done.

Thanks, but I was wanting to keep the fuel in front of the rear wheels if at all possible. In any case, I can't make a decision on anything for it until the truck is back home and rolling on its new frame.