I ran across this product:
https://www.motortrend.com/how-to/15...pick-up-system
Since the C3 tank is so square and flat it may help with fuel starvation problems.

Has anyone used it?

Does anyone have fuel starvation problems at 1/4 tank and cornering?

(My stock pickup does not reach the bottom of the tank.)

Are you able to run your tank down til it is empty/dry? Or does it still have 2 gallons of gas left in it?

 

Richard 454 uses it. I'm sure he'll comment soon.

 

I've heard a lot of good things about the Holley hydromat. That said I made up my own baffle for my 77 tank when I went EFI. When running a carburetor I never had any fuel starvation issues. But with a intank pump I'm certain I would have.

 

Yeah I think they'll work. Too bad they are so expensive.

 

It is expensive- but it works incredible. The one I used in now almost $200 (Think I paid $150 two years back- thanks you inflation!!!)
https://www.summitracing.com/parts/hly-16-111

Sucked every ounce of fuel out of the tank. I didn't have my gas gauge connected when I was testing-but I do have a fuel pressure gauge.

I was watching the AFR and the fuel pressure as I was tuning it in the driveway with a laptop.
Then the car started dropping RPM and stalled- the fuel pressure went from 57PSI to 14 to nothing.

I spent the next 15 minutes trying to figure what I had screwed up- then looked in the tank- not a drop of fuel!!!

Here's a good video- this sold me!!

 

I am using one also, built my own in tank EFI fuel supply. ( Posted pix here on CF somewhere ) Yes, it was the most pricey single part, but works as advertised, .
If you THINK it will work , It for sure WILL work.

 

So I see the benefit with EFI.

Has anyone with a Carb ever had problems going lean, hiccups in a corner, at the line, etc etc?

Or does the volume in the carb bowls just cover those issues up?

 

I’ve read the hydramat while it has great wicking capabilities that the filtration micron rating is 15 micron which is wayyyy to low for a prep up filter. This causes a reduction in flow which makes the pump work harder and can cause cavitation. This prematurely burns the pump out. Guys are having to replace pumps after a few years because of this from my reading online. Your best bet is a sump and a 100micron pre filter which is the standard sock found on EFI pumps. Also the stock EFi socks are similar to the hydramat with the wicking capabilities but lack the larger surface area.

I decided to not use the hydramat on my LS swap bc of this and used the walbro sock in the stock 78 tank. I’d rather not have to yank everything to replace the pump vs just keeping more fuel in the tank. If u autoX or drive hard on the street corner wise then get a sumped tank.

on a carb setup you can not run a hydramat as the pump has to suck from the tank (in-line or engine mounted pump) the filtration is to high and won’t flow enough easily for a carb application. You want a big 100micron high flow for a carb pre pump, where in on intank EFi pump you can get away with a smaller filter area due to its location and sucking into the pump is like an inch.

 

Also I didn't select the hyramat for another reason, the "micron rating is 15 micron" also over time will plug and require you to replace it well before the extra cost justifies it. I went with a aeromotive pump / sock which feeds a C5 corvette fuel filter / regulator for my LS3 swap (EFI)

I don't have a correct baffled tank yet, but I can get 4 x 30 minute session at my local road course before running into fuel problems. Which is about 50 liters of fuel. (13.2 US Gal ). This is not great but very manageable.

 

I'm running EFI with a return system- that's what Holley recommends for optimum operation. As other have said- not the optimum for a carb.

The big hydromat I'm running would take quite some time to 'plug'- so I really don't think that's an issue-and a great pre-filter for my pump

Originally I went with the Aeromotive Stealth Phantom system- and it failed miserably. The regular pump gas destroyed the aerospace baffle- Aeromotive acknowledged that it has happened before- and then offered
me a new baffle for only $38!!!

I'm also running two pumps- a primary and a back up- one with the hydromat and the back up with a stock sock.

If I were to do it again- I would put a sump in the tank-



https://www.summitracing.com/parts/sum-290300

 

Your return system is ideal but you could have also run the corvette EFI regulator/filter combo and only need to run one line to the engine. That filter/regulator is limited though on fuel flow and can be over powered by a walbro 450lph I think but still allows full fuel circulation back to the tank for the pump. It does not offer a vacuum reference so you can't use it for boost or anything since it's a fixed pressure. Not sure on your EFI pump sizing or your engine output but unless your boosted dual pumps can cause regulator creep as you can't set fuel pressure for the 2nd pump or you set it for both pumps but then the single pump is way off and your tune suffers. I don't believe your boosted and I'm not a big fan of multiple pumps so unless your pushing stupid HP your better off with a larger single pump (mine being the walbro 450 high pressure or the 525lph).

I'd be interested to see how your one pump makes out with that restriction on the pump with the hydramat. It seems that holley only offered a 255lph pump system until recently where I saw they are offering a 350lph with a hydramat. However they are in the business in making money and will sell you a hydramat that will kill your pump in 3 years bc then they can sell you a new pump and perhaps another hydramat if they get destroyed on removal or are not reusable... idk. The hydramat has too low of a micron rating for a pre pump filter... 100 micron only. 15 micron is for after the pump where the fuel is under pressure and easier to push through the fine media. Your a smart guy so I'm sure you already know this... but this is for all the newbs who read the thread.

Yup, aeromotive baffles are junk and the fuel destroys and eats the foam.. .same thing has been happening in fuel cells for years. Sump or baffle and be done! I've also never seen the need for a fuel cooler even after long drives. On my turbo LS motors I don't even run oil coolers as all my setups have monitored oil temps and they don't get higher than normal even with it running through a hot turbo.

 

I'm probably in the neighborhood of around 400HP- it's only 328ci. Two pumps- only one is running at a time- have the primary 255lph and if it fails with the flick of a switch only the second pump is running.

Holley says 5-10 year lifespan- so who really knows. I have the tank vented through a charcoal canister right near the tank- so maybe that will help with longevity.

Return vs returnless- I copied the car the engine came out of-it was over $100k new- and they didn't cut corners. They had used a return and a cooler. The previous version - had twin pumps- twin regulators - twin return lines - one for each bank.
I'm also running a 3 bar (58psi) regulator- as that's what the Bosch injectors supposedly like- and for wiring- over kill with two 10GA grounds and two 10GA hots- relays right at the battery.
So hoping the pump(s) is/are not an issue. I see so many installs with small - cheesy wiring and want to blame the pump for burning up.

I am not running a oil cooler- but then I've got a 12QT 3 stage dry sump- I do have a tank temp sensor- and I'll be interested to watch the temps on a street driven car.

My goals- more of a grand touring w/ creature comforts versus - protouring/ track- I do plan on putting some miles on it as retirement is just around the corner.

Mines both show and go- I mean who else polishes their fuel rails - AN fittings and has a billet regulator!!!






Blue stripe- thanks to a sharpie!!!

 

Gotcha, its a nice swap. I'm not terribly shocked by the 400hp estimate most of the European V12s aren't high HP motors. But its still at least 2 times more power than the vette came stock. A single 255 will be more than adequate for that . Ive pushed a single 450 to 750hp in my 87 TA and still have some room on pump 93 and 15lbs boost. Yes, Bosch like 58psi for the pattern (what I run too) but you can run them at 43psi no worries.Twin pumps and regulators sounds messy and introduces the ability to have different pressures on each bank vs a single that means it all stays consistent. Over complicated does not mean better! lol... but they gotta find reasons to charge so much for the cars that have the V10s and V12s.

Agreed on the pump wiring, I did something similar with a 80-82 sender with a walbro 255 HP, ran 12 gauge to a weather pack, new 12 gauge main pump ground and extra grounds on the tank as well. The 255 HP Only pulls like 9 amps at max so its overkill and it's triggered by the holley Term X EFI. You can't skimp on wiring especially with fuel pumps!

You car is nice for sure and unique! I understand the show and go... I run billet rails and color match my AN fittings but I typically don't like polished anything and prefer anodized for the protection and lack of maintenance but I still have to wipe everything down.

 

In the early 2000's, I built a 69 convertible Mustang with a 94 fuel injected 5.0 and AODE trans. I cut 5 silver dollar sized holes in the stock tank then covered them with a weld-on sump like pictured above. I used a Ford frame mounted external pump and filter and ran two new hard lines for pressure and return. I modified the sender pick up tube so that it pointed at the sump holes (which acted as a baffle) and used that as the return. The pump was mounted so that the inlet was in line with the ports on the sump. Thousands of miles and never had an issue. An inertia switch added a little extra safety.