I've been giving the EFI thing some thought, my idea was to make the surge tank in such a fashion that a Holley style fuel bowl would cap the end of the tank and use the factory Fuel pump to fill the surge. The flaot in the fuel bowl would keep the surge tank full. Then plumb the High Pressure to and from the surge.

Seems that the LP system would supply enough gas to run the engine since the HP pump would just be pushing through the system back into the surge.

Any thoughts on whether this would work or not? I feel like I am over looking something.

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It is easier to REACT,
than it is to THINK!

Middy.

Why not just use an aircooled inline electric pump, as described in one of the articles?(Electronic Fuel Injection for the Slant Six)

Right now I am in the process of installing my howell efi (tbi) kit, and really did not want to bend steel line. I looked around and high pressure flexible fuel line is expensive, esp. if you want to run it from the tank and back. The guy at the shop gave me a suggestion, he said I can use the vapor return line from the tank as fuel return. This line, in my duster goes from the crankcase filter back to the fuel vapor separator tube, and that tube has 4 vent lines attached to the gas tank. The fuel would travel through the steel line to the separator, then eventually drain back to the tank through the 4 rubber lines for what was previously intended for vapor. So if you already have this system in your car (I believe chrysler called it clean air system?) then the only return line you need to plumb is to the metal pipe already there under the hood

I'm sorry I should have clarified. I mean MPI the 40 psi style not TBI. Most versions I have seen involve adding a new line of larger diameter and using the original as the return line. Most of them also seem to involve a surge tank somewhere in the engine bay. I was just thinking if the High pressure only needs to go to and from the surge tank, why bother with a return line for the low pressure flow from the tank at the back of the car to the surge tank. the level of that tank could be controlled with a float like a carb fuel bowl.

_________________
It is easier to REACT,
than it is to THINK!

Middy.

Sounds like it would probably work, but also sounds like more work than running a return line and an inline pump. I guess you might get more fuel out of your tank on hard cornering if you design the surge tank right.

FYI, the vapor return lines will work just fine, I believe, but they only came on '70-up (about) Mopars, so you still have to bend lines for earlier cars. You don't need bigger lines for MP-EFI unless you are running a hugely built motor. You don't need more fuel to your engine between MP and TBI, and since the pressure is higher for MP, you should actually only need smaller feed/return lines for that for a given fuel comsumption.

Lou

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Home of Slant6-powered fun machines since 1988

Yeah, this will work. Ron's Injection of 'Flying Toilet' fame sells a surge tank exactly like this for their mechanical injection systems. It's for race cars that don't have room for a front mount fuel cell but should work OK on street cars.

Cecil

Fuel sitting in a hot engine bay can get hot and vaporize in the fuel rail/injectors. This makes starting very difficult. I believe the a return line (surge to tank) helps replace the hot stuff with cooler fuel from the tank.

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Cheers!
Al T