Yeah, I've got an external Walbro 255 so I was planning an external pump from the get go. It's actually pretty quiet.

 

The SE cup will work, but it won't fit through the hole. They are installed before the 2 tank halves are seam welded. You could find or make a cup that will fit through the hole. That would save having to chase down an SE tank.

 

And if going to that amount of work, it'd be worth hanging the pump in there as well. Any reduction in external fuel connections is a plus in my book. The noise reduction potential is another benefit.

For those considering this type of mod, I wouldn't consider yourself locked into the Madza FC-series components. They happen to fit nicely, but I'm sure there are a wide variety of efi-prepped tanks at the wreckers that would make suitable donors.

 

I'll have to confirm this, but my friend is parting a first gen talon and teh fuel pump assembly looks very similar to the pics posted in this thread. The talon and a FC are of the same vintage so its possible they are close enough to work, I might have to look into that, findin a FC tank isn't teh easiest thing in the world.

 

Once again, Very nice, and thanks for the extra info.

 

Hopefully it'll be of use to others. Steve's recommendations are top notch. I wish I'd heard them prior to messing about with surge tanks, as it'd have saved me a bunch of time.

 

I know this thread is a few months old, but I just got done with my tank and I would just like to add that the S5 pump unit is 1/2" too tall (the S5 tanks hold more fuel) and must be shortened in order to fit in a first gen tank. I found out the hard way, and next time would get a S4 setup to make things eaier.
Just a FYI for those who wish to do this in the future.

 

Glad to hear it worked out for you, and good point about the S5 pump. I swapped in a Bosch pump at the same time, so I can't say for certain the S4 stock unit is the perfect height. It is not a big deal to change though, as the bottom part of the hangar is spot-welded to the upper. Drill out the spot welds, and join back together adjusted to suit!

Any other issues with the install? If you have some pics to supplement the thread, toss 'em up!

 

The S3 and S4 tanks both have the same depth of 10". I didn't know the S5s were deeper. I have 3 tanks to mod for FI and I think one of the parts tank is an S5. I'll find out when I get to that point. The 1st tank I did, I cut out a much bigger section in the top to install a taller sump cup. I'm not that happy with it so far and may redo it.

 

could this be done to a fuel cell instead of reusing those old looking tanks?

 

Trochoid, if you do find that there is a difference between the s5 and s4 fuel pumps, let me know since I'm doing this same setup on my SA and with a s5 fuel pump

 

I can't help with the SA tank, never had one in my possesion, but I will post the measurements of the S5 tank, if that's what I really have.

Sure it can, and it's been done before. Biggest thing with mounting a fuel cell is the spare tire well is usually cut out and plated over.

 

Latin270,
I've not worked on a fuel cell, and can't comment on how easy it would be to adapt. So long as the stock tank is solid, there's no reason not to use it. My tank was actually in fine shape, with surface rust under the paint on the top half of the tank only. The bottom half has the heavy undercoating that was still perfect. The pics appear much worse than it actually was. The surface rust cleaned up easily, and was repainted prior to installation. The tank has lasted 28 yrs so far, I'm sure I can get another 28 out of it if needed. By then my grandkids could be driving it!

Druken,
Don't worry about pump height. It's not a show-stopper, as you can adjust easily as I mentioned earlier. Just drill out the spot welds in the lower hanger bracket, and adjust as needed. Spot weld, braze, rivet, or equivalent can be used to re-mount the lower bracket at the desired height. I adjusted mine so the pickup sock is right down within a 1/4" of the bottom of the slosh cup.

 

Pictures of my install can be seen in my 13bt buid thread: https://www.rx7club.com/1st-generation-specific-1979-1985-18/project-83-s-restoration-t2-swap-update-624258/page3/
I don't have a s4 setup handy (or else I would have used it) so I can't hold them side by side, but if you guys are fitting S4 pump assemblies in there with no problems then the S5 is definatly taller, as I said I "sectioned" out 1/2", there is a pic in my thread showing it, fuzzy pic, but you get the idea. Didn't take too long to modify and everything fits back together like stock so no biggie. As you said, doesn't have to be very pretty as long as its low enough to suck fuel all the time.
Unless your building a full on race car there is no need for a fuel cell, my tank had the usual rust on the top like renns did, a few minutes with the sandblaster and voila good as new.

 

I too installed the full slosh cup, rather than cutting it smaller to fit through the ring sized hole like renns did. But like you said it required cutting a bigger hole that the ring takes up and then making a filler piece of sheet metal. It came out pretty good, i'm happy with how it looks, i'm just concerned that the tank sealer I used won't cover everything and it will eventually be a source of rust.... When I do this again someday for my other car's swap I might think of another way to do it....