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Fuel injection has no float bowl, and my 427 LS hates fuel starvation. There is a hard climbing right hand turn on ramp that I usually red line second. The hard acceleration, while turning right, at high rpm’s will uncover my pickup if I’m lower than a half tank full. Also the pickup is uncovered while auto-crossing. This causes a heart stopping stumble and costs precious seconds on my lap times. So I decided to modify my fuel tank with a summit sump. Drill a 1 1/2” drain hole in the bottom of my tank, and weld on the sump. EZ peasy! Not! The stock tank is plastic lined and can’t be welded on. So I ordered a brand new, unlined tank from summit. I had to bend the edges of the sump to match the contour of the bottom of the tank, then have the sump welded on. I only drove it from the lift into the garage so far. I put exactly four gallons into the tank, and I’ll take it on the hard right hand climbing merge tomorrow. Brand new Summit Tank. Summit Sump! The summit sump will be the lowest part of the tank. Bend to fit! 1 1/2” drain hole. The small drain hole turns the sump into a baffle. Welded onto the new tank. I added one quart to the fuel tank, and it drained out.
I too have noticed that autocross turns will trigger the fuel light at half a tank, hence why I did the aeromotive setup when I converted to EFI. That Summit setup looks very neat. I’m looking forward to hearing how it works out for you.
I've been wanting to do this myself forever! Looked into it a few times but wasn't sure what tank to use for my 77 and I don't have a tig.
Please look at my thread , (google it I don't know how to post links) entitled, 77 EFI conversion. you will see how I did a low cost EFI fuel pump setup that after 2 years I can swear by. And NO welding!
Cheap breadloaf pan from second hand shop with a couple holes drilled in it.
This is the baffle. pressed tightly to the rubber floor (factory bladder) with this homemade fuel pump setup.
Like I said, no welding, works great on 75-77 models.
Sorry Don't mean to high jack a thread
Please look at my thread , (google it I don't know how to post links) entitled, 77 EFI conversion. you will see how I did a low cost EFI fuel pump setup that after 2 years I can swear by. And NO welding!
Thx but I'm a carb guy and the sump welded on a bladder-less tank with an external electric low psi fuel pump is my goal for now. Still EFI is cool and my 86 will remain it in some form always.
A work of....................................Be eJay!
The extra threaded plug (aircraft style) would be great for draining the tank of water/bad fuel/16 oz.'s of soft drink courtesy of the neighbor's 5 y.o. tyke.
Basically..if my little brain understands....the hole inside the tank allows fuel to always have the new sump filled (yes...i'm s-l-o-w)?
A work of....................................Be eJay!
The extra threaded plug (aircraft style) would be great for draining the tank of water/bad fuel/16 oz.'s of soft drink courtesy of the neighbor's 5 y.o. tyke.
Basically..if my little brain understands....the hole inside the tank allows fuel to always have the new sump filled (yes...i'm s-l-o-w)?
I was going to drill several 1/2” holes to drain gas into the sump. But my engineer advisor, Wild Gill, suggested that one large 1 1/2" hole, as far forward as possible was all I needed. The only way gas will leave the sump will be under extreme, high g, braking. When my need for fuel would be at a minimum. He's right, no fuel needed under braking. Hard, high g, turns won't empty it, and neither would hard uphill accelerations. Brilliant.
SUCCESS!
With the gas gauge way low, and only four gallons put into the tank, I went on a 20 mile test drive. I drove it like a race car, braking hard, accelerating to redline several times, including that uphill hard right merge lane. Not a single burp. I was going to wait for a burp before gassing up, but I could not get it to burp. So when I gassed up, it took over 23 gallons. I was down to one gallon! I never put so much gas in this car, $100 of Premium, because it always ran out of gas with about five gallons in the tank. Another successful mod!
Congrats! Where are the videos of you pulling Gs?
It's always nice to have a measurable, discrete improvement when so many mods can end up being subjective or have tangible tradeoffs.
Last edited by Shark Racer; Jun 4, 2021 at 10:42 AM.
Nice work. If you'd waited for a stumble you'd have been walking. Last time I did similar the instructions said to punch 5 big holes something like 3" in the tank, one in each corner and one in the middle. But, that didn't make sense to me since it wouldn't contain the fuel very well so I did more like you did. I put 2 x 1/2" holes at the front and one 1/8" hole at the back to ensure there wouldn't be an air pocket in the sump since the tank bottom sloped up a little. I put about 3/4 of a gallon in and went around the block to test it. The 60's - 70's GM car tanks at like 4" tall lead to all kinds of fuel starvation issues when running EFI off the stock pickup and are they too short to easily fit a good in-tank pump setup. The welded on sump with an external pump is just easy and it works.
Bee Jay’s gas tank mod.
