Fuel pump recommendation for Carbed LS?

[jae]

Like the title states, just wondering what you carbed LS guys are using for an external electric fuel pump. I looked briefly at the Edelbrock 1791 pump, just wondering if there are better options out there.

I'll be doing a 5.3L w/ a 650 cfm carb for now.

[BR3W CITY]

Since the fuel demands on a carbed lsx are pretty low, almost any aftermarket low pressure pump should work just fine; I've used Moroso, Edelbrock and Denso pumps in the past on other carb'd projects.

[jae]

Sounds good. I dont want to end up spending more money than i have to, so I'll keep looking and see if I can find something under $200.

Any recommendations on gph ratings?

[BigDan3131]

Originally Posted by BR3W CITY

Since the fuel demands on a carbed lsx are pretty low, almost any aftermarket low pressure pump should work just fine; I've used Moroso, Edelbrock and Denso pumps in the past on other carb'd projects.

Pretty low? I would say low pressure [6 psi without a reg and 12-18+ with one] maybe but when you start building horsepower its just like anything else that is carbed more is better.

[jae]

Yeah, I interpreted his statement to mean low pressure, not just low demand. I don't see why a carbed LS would use any less fuel overall than an FI engine.

Is a 120 gph rated pump overkill for a ~500 hp application, or should I think about going bigger knowing that is my approximate power goal?

[68Stepbed]

I used a Carter pump. It's internally regulated so no need for a regulator. It was about $80. Due to its design, though, it's hard to find a good place to mount. If I ever change it out, I'll go with the Holley inline billet pump. A bit more expensive, but should mount easier, and be a bit more quiet than the Carter pump.

[jae]

FWIW, I had a vender over on LS1tech suggest the Holley 12-802-1. Looks like it's a 14 psi, 110 gph pump that comes with a regulator. Has anyone had experience with this pump?

[BR3W CITY]

Originally Posted by BigDan3131

Pretty low? I would say low pressure [6 psi without a reg and 12-18+ with one] maybe but when you start building horsepower its just like anything else that is carbed more is better.

I mean pressure demand vs what is required for the injected swaps.

[LEEVON]

Originally Posted by 68Stepbed

I used a Carter pump. It's internally regulated so no need for a regulator. It was about $80. Due to its design, though, it's hard to find a good place to mount. If I ever change it out, I'll go with the Holley inline billet pump. A bit more expensive, but should mount easier, and be a bit more quiet than the Carter pump.

This is the way to go, the Carter pump has the edge in reliability.

[68Stepbed]

Originally Posted by LEEVON

This is the way to go, the Carter pump has the edge in reliability.

If you're referring to one of these--> http://www.jegs.com/i/Holley/510/12-801-1/10002/-1 then yes, the Carter is more reliable. That's why I chose the Carter over these. Alot of folks on LS1tech complained about these going out every 8-12 months.

I'm talking about one of these pumps--> http://www.jegs.com/i/Holley/510/12-890/10002/-1

Here's the pump I have.
http://www.jegs.com/webapp/wcs/store...Term=180-p4594

[jae]

What's your engine setup? No fueling issues? I don't really have a benchmark so don't know exactly what I should be looking for as far as GPH ratings.

[68Stepbed]

LS1(5.7L) stock 241 heads, stock bottom end, 232/240 .581/.581 110+2 cam, TSP? dual valvesprings, TSP 7.400" pushrods, Edelbrock Performer RPM dual plane intake, 750 Street HP carb. I'm also running 3/8" fuel line from the tank to just behind the engine, then -6AN to the carb.

So far, no major fuel feeding issues. It does seem to feel sluggish under WOT, but my trans is shifting too early which may be causing part of that. I also may have the floats set low, which can cause that. I removed the sight plugs while tuning a few days ago, and no fuel seeped out.

As for GPH ratings, most pumps will have a description for the intended use of the pump, examples: street use(daily driver), mild performance street, street/strip, and racing.

For a stock or mild cammed 5.3, anywhere between 70-100 gph will be fine. If you decide to turbo/supercharge, or run nitrous, you will need 100+GPH

[BigDan3131]

I always build a fuel system as though I were going to make a thousand horsepower, overkill never hurts and doing it once is cheaper in the long run.

Do you want to run a regulator, is one question you need to think about. I would because I prefer having the volume at hand when I mash the pedal to WOT. I'm using a Holley pump that's rated at 160 GPH which will support about 750 HP based on my line sizes. On the other hand my friend has a Holley Blue pump with 1/2" line all the way from tank to dual carbs on a blown 540 making 980HP because that's what his engine builder told him to run. Big pumps will last longer and run cooler with a return line, which I also have.

[chuckmc8]

I'll be doing a 5.3L w/ a 650 cfm carb for now.[/QUOTE]

Does this mean that you are planning to run fuel injection later? If so, it's cheaper to go that route now if you have serviceable components on your 5.3

[jae]

No idea what plans are for the future. At one point I had considered buying a short block and building it up with LS1 intake and fueling components, and it's pretty cheap to get the stock LS1 stuff. However, it's hard to beat the look of the carb in an old truck like this (not to mention I've already got the carb and tuning will be much easier). I've toyed with the idea of supercharging or turbos in the future, at which point I think I would want FI, but I'd likely redo 90% of the fuel system for that setup anyway, and it's YEARS in the future if at all. I need to get the truck running soon and think this will be the quickest way.