Billy Shears Posted September 23, 2014 Report Share Posted September 23, 2014 Anybody here done one of these? I'm looking at the Aeromotive Phantom, but I am leery of that foam baffle. Aeromotive say the foam is not supposed to have a limited lifespan, but if it's the same stuff they use in fuel cells (and why wouldn't it be?) I've read that stuff should be changed out every few years. I'd rather not deal with the PIA of dragging out my gas tank every couple of years to change that baffle. Still less do I want that foam coming apart in my fuel tank after a few years. Ideally, I'd like to put an LS1 fuel pump from a 99-02 GM F body, but I don't know if the Avanti's gas tank is too tall. Anybody happen to know the height on the Avanti fuel tank? Otherwise I'll have to take out the back seat and measure it. Link to comment Share on other sites More sharing options...
Gunslinger Posted September 23, 2014 Report Share Posted September 23, 2014 Why not just mount an electric pump between the frame rails just forward of the rear axle? There's lots of electric pumps on the market that will work very well that way...and no modifications to the gas tank are necessary. My Avanti is set up that way...the only issue you might find is the pump will be noisier than an inside the tank type. Different brands and models are better or worse when it comes to the noise factor. Whichever way you decide to go, I would suggest replacing your rubber fuel lines with fuel injection rated hose...it designed to be pressurized where rubber fuel line for carbureted cars is not. Also...depending on the pressure rating of the electric fuel pump you choose, you may need to have a pressure regulator installed...carbs use maybe a 5-6 psi line pressure and many electric pumps are much higher than that. Link to comment Share on other sites More sharing options...
Billy Shears Posted September 23, 2014 Author Report Share Posted September 23, 2014 (edited) I'm putting an EFI in this thing -- I've just about decided on one from Hamilton EFI. I was going to go with the Powerjection III, but I have an R2 with an A/C by putting the compressor (a Hamilton from an '86 Chevy Celebrity) where the surge tank used to be, and this set up leaves insufficient room for the Powerjection throttle body -- the hose connections stick backward just a tiny bit too far. I was looking at the Fast EZ Efi, but the tech at that company says the only way to set it up with a supercharger is to use the EZ EFI throttle body, and the XFI engine control system, which jacks the price up to over $3000. Hamilton can put together a system using OEM GM parts for under $1400, and I have the advantage of knowing I can still get components for it fifteen or twenty years from now if need be. I've thought about an external pump, but I'm going to have the gas tank out soon anyway for cleaning and rustproofing, and everything I've read makes me think an in-tank set up is the better way to go. If I am going to spend the money for EFI, I'd rather do it right. Edited September 23, 2014 by Billy Shears Link to comment Share on other sites More sharing options...
Avanti83 Posted September 23, 2014 Report Share Posted September 23, 2014 If this one represents the actual setup. You should be able to make it work by adjusting the length. http://www.ebay.com/itm/NEW-HERKO-FUEL-PUMP-E3621S-FOR-VEHICLES-CHEVROLET-AND-GMC-1988-1991-/171329845067?pt=Motors_Car_Truck_Parts_Accessories&hash=item27e40df74b&vxp=mtr My one concern is the need to put a baffle in the bottom of the tank to make sure the pump doesn't run dry. A quick death for an in-tank pump. When I put the in-tank setup from a 91 Caprice in my 54 Studebaker, I made a sump lower than the tank as the pump setup was to long for the OEM tank. In the Avanti, you would probably just need to place a circular panel with holes where the pump pickup is as a baffle. Don't just buy the pump setup from your FLAPS, go to a wrecking yard and buy the entire tank assembly as the pump mounting flange is commonly specific to the pump. Most are an o-ring sealed twist setup. You can weld the flange to the top of your tank. Even if the tank is plastic, the mounting flange is metal. My tank was plastic but I removed the flange and welded it on my tank on the 54. That will give you everything you need and just replace the pump, which is not expensive. The hose fittings on the pump are a GM setup. I just replaced them with a compression fitting that converted to NPT thread and installed hard lines all the way. Now days the EFI hose available will probably let you just slide it on and clamp it but you will see what's needed when you get the setup. The Chevy setup is nice as it includes the gas float but I'm not sure the resistance is correct. It isn't hard to find an SW gauge that will work and match your gauges OK. That's the route, but if I were to do it again I'd just install the external pump. My 83 has a Holley EFI and I just used the external pump and the in-tank sender that was there. Your choice however, Bob Link to comment Share on other sites More sharing options...
grobb284 Posted September 23, 2014 Report Share Posted September 23, 2014 I have utilized both in tank and external pumps. The external can be quiet with proper thought when mounting and plumbing. Cost wise the external are usually less expensive and easier to swap out. I am utilizing an external pump with the LS1, with the Corvette regulator with integral return. Link to comment Share on other sites More sharing options...
Billy Shears Posted September 23, 2014 Author Report Share Posted September 23, 2014 Actually, the setup I was thinking of was this one: http://www.vetteworksonline.net/ls1_conversion_fuel.htm A 99-02 GM F Body. It comes with a baffle included. Link to comment Share on other sites More sharing options...
Avanti83 Posted September 23, 2014 Report Share Posted September 23, 2014 I like the included baffle setup. I think it's going to be to short as there is only 1" of adjustability and the pump pressure may be to high for the std Hamilton EFI TBI setup. It might also be lower in volume than is required for supercharging. I don't know for sure but just thinking out loud. Bob Link to comment Share on other sites More sharing options...
Billy Shears Posted September 23, 2014 Author Report Share Posted September 23, 2014 (edited) I've already found out the height should not be a problem. The unit is 10 5/8th inches high, with an ability to adjust up or down about an inch. The Avanti's fuel tank is 10 1/2 inches high (according to someone over at the SDC forum who measured it). LS1 fuel pumps can supply fuel to engine up to 600 HP, so I don't think volume will be a problem either. I'll have to check about pressure. Edited September 23, 2014 by Billy Shears Link to comment Share on other sites More sharing options...
Avanti83 Posted September 24, 2014 Report Share Posted September 24, 2014 It looks like you are on top of the install. It just didn't look that tall. Keep posting about the EFI setup, I would be interested in what it looks like and how it works. The reason I mentioned the pressure for the TBI's is about 15 PSI. The early TPI's 40 PSI and later like you have run about 55 or so. It could be just a pump change however or a regulator. The folks that supply the systems will know. Good luck, Bob Link to comment Share on other sites More sharing options...
IndyJimW Posted October 21, 2014 Report Share Posted October 21, 2014 You can check out what I used for my setup. http://www.aoai.org/forums/index.php?showtopic=1896&hl=%2Bfuel+%2Bpump or search "Fuel tank removal" in Avanti Pub. Working great, can't hear it and solved the tray in bottom of tank problem. Jim Wood Link to comment Share on other sites More sharing options...
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