The smaller one. The large one looks like what is on the Aeromotive web site. The smaller one only sticks down 3" below the tank.

Sam

_________________

Sam,

I’ve been watching this because I’d like to figure out the same things. I know you’d rather have someone who had done it and knew what they were doing answer these questions but I’m hoping some new perspectives might get the ball rolling. (Even though I haven’t done it and don’t know what I’m doing)


(I'm assuming you mean mounting it with the deepest part forward) I don’t think I’d put the sump on the front. I do think all of this stuff is designed around racing, and particularly the kind where cornering isn’t important as long as everything works with the front wheels off the ground —But still, when accelerating you are draining the sump (with the fuel pump) and the fuel will be sloshing in the correct direction. When braking, it could pull fuel away from the pickup and it could suck air into the fuel system but I’d rather do it while braking than while accelerating. The way I see it, we can’t get away from this problem. It can’t be cured. We’ll either slosh fuel out of the sump while braking or while accelerating and we have to pick one.

I don’t know if you’ll be hanging anything on the sump except for one or two fuel lines. (I’m not sure about the second bung either) I don’t think there would be room for anything else. The bungs take up most of the rear panel.

Another thing I’m realizing while thinking about this is that it’s easy to try figuring where the fuel is going to slosh when there is only enough in the tank to fill the sump. In reality, our fuel gauge would have been reading empty for a long time by then. Still, if I think about it long enough, it’s hard to imagine any type of pickup or in-tank pump working without a surge tank even though I know it has been done.


You won’t have the tank cut open according to the instructions It appears that the original floor of the tank becomes the baffle. Instead of cutting a huge hole in the tank, you only drill holes in it by a template. Theoretically, you could play with the design of the holes to address different things but if you make it hard for fuel to get out of the sump, it’s also going to be harder to get fuel into the sump. It seems fuel would spend more time trying to get in than out, though. Maybe one hole drilled at the rear would be enough to feed a rear mounted sump and it would be very hard for fuel to get back out. With no holes in the front, fuel couldn’t slosh out when braking.


I don’t know. My truck tank is behind the seat with the narrowest portion of the tank on the floor. I’m assuming you have a tank with a wide, flat, level bottom. If the lowest end is toward the rear it would be better for a rear mounted sump. If it’s angled too much toward the front it could drain a rear mounted sump on level ground. Conversely, it could drain the sump if you mount it on the front...


I don’t know how much pressure the return line should/could have or how much it would take to pump fuel into the bottom of a full tank. But, when braking with an empty tank, you would be bypassing fuel to the sump - just another safe-guard against sucking air.


I would think an in-tank pump would need to be in a sump also. I heard a rumor that Holly is making an in-tank pump/surge tank combined but I haven’t been able to find it on Holly’s website. Holly Pt# 12-923

http://tinyurl.com/323vfl

Danny

On GM truck and B car tanks the pump/pickup is mounted in a plastic bucket or sump ....the return line dumps into the bucket. Fuel can slosh into the bucket easily...but not out.

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

I finally went out and crawled under the car and looked at things. There is insufficient room to hang a sump and pump on the front. Shocks, and rear pumpkin are all pretty close. The A body tank slants up toward the reat, so the sump on the rear would actually amount to level. There is lots of room to hang the pump right behind it. Drilling holes in the tank floor to fill the sump cetainly would limit the amount of slosh that could happen. I am leaning in that direction. But, am still open to any good ideas aobut in tank pumps. In the mean time, I feel encouraged to buy a new tank to work with. They are pretty cheap. $220 from Mancini.

Sam

_________________

Try this site: http://www.rickshotrodshop.com/car.htm

They made a custom stainless steel gas tank for my '63 Dart GT convertible for the day the fuel injection is installed. It looks similar to the stock tank, but is much heavier. Two different brands of internal pump are offered.

The web site doesn't list a tank for the A body, but they had no trouble building one.

--Walt Jackson

That's interesting. I thought I had decided to go with a sump and an external pump, but after seeing their web site, I sent Ricks an e-mail and will await there response. I asked Lou, AKA Dart270, about his fueling set ups, and he has external, rear mounted pumps on his cars, and they work pretty well until road racing with less than 6 gallons of fuel. I figured a sump would cure that. It seemed like the chaep way to go. So I will hold off on any decisions I make until I hear back from Ricks. I had that link bookmarked, but hadn;t read all the print carefully enough to see that they include an internally mounted fuel pump. ONce I saw no A body tank, I just kind of went on from there. Do you remember the cost of your tank?
Thanks.

Sam

_________________

Ooo, one of the guys on Mopax was saying that he was crawling under late GM TAs and Camaros (~2000?) and thought it might be easy to adapt one of those with a stock in-tank pump to an A-body.

Might be worth a look.

Lou

_________________
Home of Slant6-powered fun machines since 1988

I had a look at GM B cars( Fleetwood, Caprice, Roadmaster)......plastic tank ,,,internal pump. It looked almost promising.....

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

Double post?
Sam

_________________

You mean the entire tank, or just the pump set up?

Sam

_________________

whole tank

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

It would have to be a '94-'96 B- body with MPFI. '91-'93 had TBI

_________________
Chris'
Autobody
Restoration
Service

Well, it's a done deal. I called Ricks Hot Rod Shop in El Paso, and they are installing a GM fuel pump from a Corvette into an A body tank, complete with internal inti-surge tank. STrap it on, hook up the wires, and the hoses, and it is ready to roll. I guess I am getting too old to go lie under an old car and try and figure out how I'm going to get that thing out of there without the car falling on me.

The deal is, I send them a repro tank, and they install the sump and fuel pump. Mancini is drop shipping directly to Ricks. The sump is kept full by the return line. Apparently it is OEM style all the way. So there you are. Thanks for all your advice.

Now here is another issue. In reading on the internet, I came across information that said these high volume EFI pumps require better venting than the cap can supply. They said it can actually collapse the tank if the vents are not adequate. I don't know when Mopar switched to an unvented A body gas cap, if ever. What can anyone say about that? I would appreciate advice about venting the tank. What hardware to mount where? And the internet article advises putting a filter on this. Plus, what year filler pipe and gas cap should I look for?

Sam

_________________

When I worked at a GM dealership we always had people come in with check engine lights on due to a missing (left at the pump) or cracked gas cap. My assumption is that the venting system is a very controlled system of many parts, so I really doubt that a vented cap is going to cut it. I think there must be additional canisters/vents added to the system. My brother works for a diagnostic hotline (phone grease monkey), I'll ask if he can get a diagram of a 'Vette fuel system. What year pump are they installing? Should I get diagrams of other makes for comparision?

_________________
Chris'
Autobody
Restoration
Service