Fuel System: Fuel injection pump in an Avanti gas tank

[grobb284]

Has anyone installed a fuel injection pump in their Avanti gas tank? Any photos,insight, or suggestions to this from your experience?


Did you do it yourself, or use Rock Valley, or another supplier?

[Gunslinger]

I have an Avanti II with the GM engine...it has Edelbrock EFI and came with an electric fuel pump that's mounted externally under the cross frame rail beneath the gas tank. It's far easier than trying to come up with an internal setup. Electric pumps other than Edelbrock would be mounted similarly.




Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, cocky and in general a malcontent.

[Mike Van Veghten]

grobb -

While I havent done what you are doing...I did make some heavy duty modifications to my Conestoga tank for the installation and clearance for the Quick Change rear end I put in.

That said...I'd just go buy a used tank that has the boss for the pump you want to use, cut out an area of at least 1" larger than the actual area you need...
Cut a matching hole in your existing tank and tig weld it in.
You'll obviously need to pick a pump that will fit the cross sectional height of your Avanti tank.
Or again, modify as required. I know you're used to that!

Make sure none of the body panels are in the way for the fuel line clearance.

I used shop air (lowered to about 12lbs.) and soapy water to check for leaks. Found one, soldered it closed.

Working well so far..

Mike

[sweetolbob]

From JDP's earlier post, I now know that the Avanti tank is tall and narrow.

The one problem you will need to deal with is fuel starvation to the electric pump. Just a couple of seconds and it's toast.

I used a GM high pressure pump 55 PSI+ in my 54. The tank was shallow, so I removed the fuel pump neck from the GM tank and welded it to the top of the Stude tank but not before cutting a hole in the bottom of the tank to let the pump assembly hang below. I put the pump assembly into the neck and measured the depth it hung below the tank. Made a sump by bending a sheet of 16 ga steel, the height of the sump, to the diameter I needed and welding the side seam and added a bottom with a drain plug.

Eureka!! Had the pump in the tank and no fuel starvation because of the sump.

You will need to do something similiar only inside the tank to make a sump.

As Mike said, just weld and check with about 5-10 psi air. I migged the welds as I don't have a TIG.

Bob

[PlainBrownR2]

One suggestion if this fuel injection pump is going on an Avanti with a carb. While I don't have an Avanti, I have an external Holley electric fuel pump from having a prior TBI on the car. That pump had the capability of, oh, about 30 psi going into a system that was only designed for 7 psi. Before starting the car I had installed a simple adjustable Holley 3 port regulator(In, Out, Return) before the carb to ensure a set pressure of 7 psi was going into the carb. Therefore:

Install a regulator if this is a carbureted car. Excessive pressure could very well blow fuel out the seals on the carb, which could make for a very explosive situation and a very bad day.
I would also recommend a fuel filter somewhere midline in the fuel system. I dunno if in-tank pumps need anything before going into the pump as many have that sock on the pickup.

[img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201950%202r5%20Studebaker%20Pickup%20with%20turbocharger/P1000137-1.jpg[/img=left][img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201950%202r5%20Studebaker%20Pickup%20with%20turbocharger/P1000145-1.jpg[/img=left][IMG=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/Ex%20Studebaker%20Plant%20Locomotive/P1000578-1.jpg[/IMG=right]
[IMG=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/My%201964%20Studebaker%20Commander%20R2/P1010168.jpg[/IMG=right]

[wcarroll@outrageous.net]

I'm installing an inline on the frame rail behind the driver's rear wheel that's specific for use with port injection applications. That way it's easy to get to and in a position where the fuel lines are already routed. I'm running a '96 LT1 motor.

The inline pumps are little spendy compared to carb application pumps, but are far easier to install and service than an in-tank unit (just did my '96 Tahoe).

The Avanti has a high tank, so the pump doesn't have to work as hard as it might in vehicles with drop tanks. Plus a lot of in-tank units are just as noisy if not more than some external pumps -and even worse when you're low on gas.

Since the Avani tank is mounted behind the rear seat and strapped to a fiberglass body -I'd be really worried about cabin noise.

Summit racing has some good prices on inline fuel injection pumps starting at $79 for their house brand:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DG3138&N=700+4294836965+115&autoview=sku

http://community.webshots.com/user/s2dbaker?vhost=community

[grobb284]

Will,
Thanks for the information on the inline pump. I had no idea they were that inexpensive.

I had made a tank before for a 1955 Chevy, and had mounted it behind the rear seat not unlike the Avanti. It was more work than I should have invested. We made our own baffles, as well as the subassembly to hold the pump and seal with a neoprene gasket. Using a factory pump, it was pretty quiet. However, we had made a cover for the tank, putting it on the outside of the car, not the inside. This may have had a big influence on the perceived quietness.



You can see the provision for covering the tank to place on the ouside of the car.





If I did the intank pump again, would like to use a twist & lock pump assembly. However, the inline would be the easiest, if it is quiet.

I installed a fuel pump to circulate the supercharger lubricant through a cooler. It sounded like somone was hammerimg on the frame, it was quite loud and annoying. We quieted it by mounting (isolating) it on polyurethane bushings.

I like the idea of an external pump, but 5 years ago they were noisey and prone to failure by not being cooled by the fuel like an intank pump. I wonder if that has improved, as Summit only warrants the pump for 90 days?


I guess part of my question is: For the inline pumps, has the reliability improved, and are they a lot more quiet now?


Will, you are in process of installation: How long until completion for some practical experience? Are you planning on using the Summit pump?

Anyone else have practical experience on an inline fuel injection pump?

[Jeff_H]

Many 80's fords (and maybe f150s in the early 90s too) used a dual pump setup on the EFI. There is a low pressure in-tank pump and a high pressure pump in-line with the fuel hose mounted on the frame. The in-tank pump only puts out about 5psi or so, high pressure pump boosts it up high enough for the typically 35psi regulator to work up at the engine. I think they can produce 60psi at least.

I have a EFI equipped V6 ford engine in my '53 that used that setup. I have a stock type in-line high pressure pump mounted using the ford bracket (with its rubber isolators and foam sleave for noise) to the floor of the car under the rear seat next to the frame rail.

The in-tank pump part caused me some concern for a while. What to do? There are companies that will install a pump flange into your OEM tank but they were quite $$$$ I found a small quiet rotary vane pump intended for carb applications that puts out about 6psi. I drilled and soldered fittings into the upper front edge of the tank and installed brass compression fittings so I could stick 3/8" brake line tubing down into the tank. The suction side tube has a short hose to a filter and into that low pressure pump. The pump is mounted on a bracket that is screwed to the tank seam so it hangs below the mid point of the tank sort of close to the level of the bottom of the tank. This was so it doesn't need to develop much suction to pull gas from the tank. That pump feeds a line to the high pressure pump and main filter (mounted to the frame rail). From there the high pressure line goes to the engine. The return line comes back to the tank and goes into the other tube and fitting.

This setup has worked pretty well for the nearly 15k I have driven the car since it was done. I had some problems with the original low pressure pump intermittantly conking out though. The high pressure one couldn't draw fuel through it from the tank so the car would stall. Seemed to happen only when I was at a show and wanted to go home though So far the replacement one has been fine.

I've some pictures of the low pressure pump and the fittings on the tank but they are on film and I've not scanned them.

One thing not mentioned in this thread that I made sure to do was install the inertia switch from the donor car I got the engine from. In case of a collision, the switch cuts power to the pump so you cannot have a broken line spewing gasoline all over.

Jeff in ND

'53 Champion Hardtop

[grobb284]

Jeff:
I agree to your safety caution, have already picked up an inertia switch, apparently Ford typically mounts these in the trunk.

GM uses an oil pressure switch, assuming that upon a fuel rupture, the engine dies.

I'm not sure which one is the best concept.

[Alan]

You could use a Ford F150 89-93 Delco EP286, 36 to 40 GPH, or if you need a larger pump a Delco EP424 which puts out 40+ GPH. They run about $90 are external and you should put in a 1/2" pipe bung and run some -8 fuel lines.

[emc53]

I am planning on doing the same thing to my 53. I have an LT1 and I have just installed my 4th inline pump.I can't get them to last very long . Have you ever checked if GM has made a tank that will fit ?

[1962larksedan]

I am planning on doing the same thing to my 53. I have an LT1 and I have just installed my 4th inline pump.I can't get them to last very long . Have you ever checked if GM has made a tank that will fit ?

I'm starting to wonder if a 1977-90 GM B body (Caprice, etc.) gas tank would fit; some were FI BTW, since they bear a strong resemblance to at least Lark car tanks. Admittedly the fuel filler may have to be tweaked but still..........

[daytonadave]

Another car that has a fuel tank behind the back seat is the Lexus SC models from 1992-2000. I have a 92 SC400. The fuel pressure regulator is set at 41 psi. A person could get one from a junkyard fuel lines, tank and all for not much money. I've got 157,000 miles on mine and it is all original still. You would have to adapt the fuel gauge somehow. Just another thought.

[sweetolbob]

I'm starting to wonder if a 1977-90 GM B body (Caprice, etc.) gas tank would fit; some were FI BTW, since they bear a strong resemblance to at least Lark car tanks. Admittedly the fuel filler may have to be tweaked but still..........

I brought one home (90 Caprice tank) thinking the same thing. It's just to deep and overall to big to adapt easily. You could cut out the trunk floor and adapt it by installing it higher in the trunk but.....

I chose to adapt the neck to my 54 tank, use the assembly with a high pressure pump adapted ( Caprice is TBI ) and add a sump about 2" deep to keep the fuel around the pump.

Bob

[64V-K7]

((((I'm not sure which one is the best concept.))))
I'll have to bank on Ford 'having a better idea" on this one. I'd prefer the fuel pump quit by being bumped, rather than waiting for the engine to cut off