69442

I'm thinking of buying a Spectra Premium EFI replacement fuel tank part #GM34RFI with the internal fuel pump for my 72 Cutlass. I have a 500HP carbureted 455 currently in the car with a Holley Blue pump and regulator, that is way too loud for my liking.

The specs on the Spectra in-tank fuel pump are: 85-115 psi and 50-60 gph. Is this enough fuel flow for my engine?

Thanks for any input!

TripDeuces

Do you have EFI? I'm guessing you don't since you're using a Holley blue pump.

http://www.fuel-pumps.net/fuelpumpsfaq41.html

Going by this site, and I'm sure there are a thousand more just like it, you'll get this equation. 500hp x .38 = 190 lph. 190 lph = 201 quarts or ~50 gph. That pump will be more than enough but I think it's pressure rating is way above what you need. You need to get a pump designed for carbs and not EFI. That might be a bit of overkill

70cutty

I have a Edelbrock Quietflo on my car, had a Holley on one of my other cars, Edelbrock is a lot more quieter. Once the car is on you can't really hear it. Just another option.

That pump is designed for FI, 85-115PSI is a bit much when all you need is 7 PSI.

Smitty275

I'm not up on the in tank pump set ups but that is a lot of pressure to be reducing to 5-7psi for a carb. Check around and see if they offer a carbed application. You might want to look at Aeromotive. I think they have several different offerings and are very high quality.

rustyroger

Are you sure you're reading it properly?. Modern EFI systems normally run about 40 psi.
A fuel return system might be necessary for a continuous operation pump if you don't already have one.


Roger.

69442

Thanks for the responses. I am running a Holley 750 cfm. I double checked the specs on the Spectra tank and they are correct. I like the idea of the in-tank pump and the price is a little over $300 from Rockauto.com. Aeromotive has some nice units, but a lot more money. They have a complete tank set-up for around $700 and a drop-in unit for around $500. I agree that psi seems like too much. Maybe I'll just look into a quieter external pump. Has anyone tried the Mallory 140? I hear that they are very quiet.

garys 68&72

Yeah, you don't need the efi pump for 7 psi.
I've run the Mallory 110 and 140 before. VERY happy with them. A bit quieter than the Holleys. Be sure to mount them on rubber grommets and they'll be quieter.
BTW, is there a reason you're not running a mechanical pump?

Smitty275

The Mallory Comp 140 is a good deal and an excellent pump. I highly recommend a return style system. #1They are much quieter. #2 The fuel is always moving and never heat soaks.#3 Since the fuel is always moving the pump is never dead headed, thus being quieter and lending to extended pump life.
Always over build the fuel supply. Too little capacity will bite you. Too much capacity will never hurt. Its better to have and not need .......

69442

[I]BTW, is there a reason you're not running a mechanical pump?

I have Edlebrock aluminum heads and clearance is a problem for the mechanical fuel pumps, unless anyone knows of a new version mechanical pump that will work. I do NOT want to do any grinding on the head.

garys 68&72

Makes sense.
Btw, I've run the Mallory 110 deadheaded in a boat with a supercharged Gen V 454 (no fuel pump provision) where a return line was not practical to install. No issues at all. But as Smitty pointed out the 140 with external regulator has advantages.

Stevec

I used the aeromotive set up an-8 feed and return lines. I used aeromotive regulator,fittings and summit braided stainles hoses and this set up works awesome!

If I remember correctly the tank part number was 18301.

cdrod

Does anyone know what brand of pump is in the Spectra GM34RFI tanks? I know this thread is over a year old, but it made more sense to post here as the info will be helpful to others looking at the Spectra tanks. Thanks!
Rodney