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I need to make a proper fuel return for my external pump (Efi). The plan is to remove the old return, drill a hole, baffle/flare and JB weld a bulkhead. For the flare I 3dprinted a tool that can be inserted in the tank. The flare will give a lot of additional support. The bulkhead will have a downpipe.
cajos
Since a 72 has the fuel sender on the underside, why don't just remove it, braze in a a piece of tubing and let the efi fuel return come in from underneath. That's what I had on mine before I went with an internal fuel pump.
It's a lot easier and you can do the work on the bench instead of on the car.
I hope that is clear. It is still on the car but I sealed it. If you want a picture just let me know. I did that ages ago but I read somewhere that it was better to have the EFI fuel return below the fuel level.
Last edited by carriljc; Sep 20, 2020 at 05:19 PM.
cajos
Since a 72 has the fuel sender on the underside, why don't just remove it, braze in a a piece of tubing and let the efi fuel return come in from underneath. That's what I had on mine before I went with an internal fuel pump.
It's a lot easier and you can do the work on the bench instead of on the car.
I hope that is clear. It is still on the car but I sealed it. If you want a picture just let me know. I did that ages ago but I read somewhere that it was better to have the EFI fuel return below the fuel level.
I'm in this situation as well. I was wondering if I could just bring it in on the bottom. I will need to get it away from the sender though. Anyone with a diagram where to locate the return?
ZAKsPop
Is your fuel supply on the underside of the tank? If so, then just drill a hole in a place where you can braze in a 3/8" piece of tubing. Nothing terribly special. Mine used to come up just as a stub and didn't affect the level indicator....
BUT - you might want to consider going to an internal fuel pump. Mine installs and is removable from the top. If I were to do it nowadays I would use and modify an 82 sending unit assembly instead of fabricating a bunch of stuff and you can find lots of different cannister type EFI pumps where the fuel returns to the cannister. .... (that being said it's been working fine for over a decade).
See here: https://www.corvetteforum.com/g/album/6185062
Let me know if you want a picture of the 3/8" tube I brazed onto mine for fuel return.
Originally Posted by ZAKsPop
I'm in this situation as well. I was wondering if I could just bring it in on the bottom. I will need to get it away from the sender though. Anyone with a diagram where to locate the return?
If I were to do it nowadays I would use and modify and 82 sending unit assembly...
That's what I'm running on my 79. I got a replacement 82 sending unit, a Walbro 255Liter pump and a "TPI Camaro Walbro mounting kit" to install the pump in the sending unit. Everything went right together without any modification.
That's what I'm running on my 79. I got a replacement 82 sending unit, a Walbro 255Liter pump and a "TPI Camaro Walbro mounting kit" to install the pump in the sending unit. Everything went right together without any modification.
If I could do it all over again, this is what I would do, with a Holley Hydramat setup on the bottom to act as a sump. Holley now has a Hydramat kit for the 78-82 cars.
If I could do it all over again, this is what I would do, with a Holley Hydramat setup on the bottom to act as a sump. Holley now has a Hydramat kit for the 78-82 cars.
I originally purchased the Holley drop in Hydramat kit, but sent it back and put together my own setup. The Holley sending/fuel pump unit doesn't have a location for return line, and I only run return style systems on the cars I build. Not to mention, what I put together was 1/2 the cost.
With that said, I'd like to have one of the larger ~20" x 15" Hydramats that would cover a majority of the fuel tank bottom, but at near $700 for one, I just couldn't justify it. Even the little "sock" version is $125 and I don't see how it could make making any difference (it doesn't cover enough of the tank to deal with low fuel level sloshing).
I concur...the prices for those hydramats are NOT justifiable for me. Not only that; returning to a "cannister" type system system is a better idea.
I tested mine by running it till my pump lost suction. I had a friend with me to refuel when I ran out. Sucked my tank just about dry before I lost fuel pressure. Test Sat. Test Complete.
Last edited by carriljc; Nov 30, 2020 at 09:47 PM.
I originally purchased the Holley drop in Hydramat kit, but sent it back and put together my own setup. The Holley sending/fuel pump unit doesn't have a location for return line, and I only run return style systems on the cars I build. Not to mention, what I put together was 1/2 the cost.
With that said, I'd like to have one of the larger ~20" x 15" Hydramats that would cover a majority of the fuel tank bottom, but at near $700 for one, I just couldn't justify it. Even the little "sock" version is $125 and I don't see how it could make making any difference (it doesn't cover enough of the tank to deal with low fuel level sloshing).
Interesting, I didn’t look at it closely. I assumed it was the brackets & mat.
I’m running Aeromotive Phantom, with AN-6 supply and return. Returnless setups seemed to be too problematic.
ZAKsPop
Is your fuel supply on the underside of the tank? If so, then just drill a hole in a place where you can braze in a 3/8" piece of tubing. Nothing terribly special. Mine used to come up just as a stub and didn't affect the level indicator....
BUT - you might want to consider going to an internal fuel pump. Mine installs and removed from the top. If I were to do it nowadays I would use and modify an 82 sending unit assembly instead of fabricating a bunch of stuff and you can find lots of different cannister type EFI pumps where the fuel returns to the cannister. .... (that being said it's been working fine for over a decade).
See here: https://www.corvetteforum.com/g/album/6185062
Let me know if you want a picture of the 3/8" tube I brazed onto mine for fuel return.
It is a stock tank. I've purchased several fittings but then realized I would have hell trying to get to the inside to tighten them. Never thought about brazing them in. I've already got the external pump kit from FiTech. I wish I would have sprung for a new FI tank instead but now it is too late. So deep in this car now.
It is a stock tank. I've purchased several fittings but then realized I would have hell trying to get to the inside to tighten them. Never thought about brazing them in. I've already got the external pump kit from FiTech. I wish I would have sprung for a new FI tank instead but now it is too late. So deep in this car now.
You braze the fittings into the pickup (OFF THE FUEL TANK). DO NOT BRAZE ON A USED FUEL TANK! BOOOOOOMMMM!!!!!!!!
A couple of pics of the underside view of my modified fuel sender locking plate. If I was doing it nowadays I would use a tubing bender and angle similar to the fuel supply tube-then braze it in.
You can see where I brazed in the fuel return tube (now sealed).
When I went to an internal fuel tank I just brazed a bolt into the former fuel return tube as you can see. For the fuel supply I just "plugged" it (in case I ever need to go back to a carb...but I really don't foresee that).
ZAKsPop
Can't you return it? I hadn't thought much about it since I did mine. Somebody sells a contraption with an EFI pump that slips in in-place of the old fuel sender from underneath. Looks pretty cool..... ridiculously expensive for what it is, but a good idea. Anyway -- somebody reported that theirs failed and that's when I realized that it really is a lot better to have a fuel pump coming in from the top---- I can remove mine out of the top without dropping, nor draining, the fuel tank. Something to consider. Let me see if I can find that cool contraption.....
Originally Posted by ZAKsPop
It is a stock tank. I've purchased several fittings but then realized I would have hell trying to get to the inside to tighten them. Never thought about brazing them in. I've already got the external pump kit from FiTech. I wish I would have sprung for a new FI tank instead but now it is too late. So deep in this car now.
Here is this cool thing. Looks quite neat but it is returnless, at a one fixed pressure so non-adjustable. Wouldn't work for me and my fuel pressure (not to mention that I prefer adjustability) and if it fails you have to drain the tank and do it from underneath.
To me, I'd like to see them add a 5/16 or 3/8 return line barb, move the regulator to the return leg and provide a T fitting and hose (I know I've seen this setup on an OEM vehicle but can't remember which one). With this layout, the customer could decide to either run a return or returnless style fuel system and if the customer wanted to have a regulator at the front of the vehicle (for vacuum or boost referenced fuel pressure), then they would just have remove the in-tank regulator (of leave it provided the front regulator was never set below the in-tank 58 psi setting). That would make the setup fully worth the price.
A couple of pics of the underside view of my modified fuel sender locking plate. If I was doing it nowadays I would use a tubing bender and angle similar to the fuel supply tube-then braze it in.
You can see where I brazed in the fuel return tube (now sealed).
When I went to an internal fuel tank I just brazed a bolt into the former fuel return tube as you can see. For the fuel supply I just "plugged" it (in case I ever need to go back to a carb...but I really don't foresee that).
Thank you, anything special on the inside or just straight
Tool for tank mod (Efi)
but I did say it's a lot easier to work on the bench than underneath.