Low Pressure Electric Fuel Pumps

[Eoth]

Ok..... Swapping in an explorer 5.0 but staying with carb. Specs say that a Holley TA should have 5-7 PSI. HOWEVER looking at all the electric fuel pumps, the selection is extremely limited for a pump in that exact range (which blows my mind). That means that I will have to regulate it down. Am I nuts for not wanting to use a regulator (always trying to keep it as simple as possible). If I am going to regulate it down why would I even care if it is high or low pressure (no real difference between turning it down 2PSI or 20PSI).
What am I missing? Any recommendations (part numbers would be helpful) for a decent pump that doesn't require a regulator?

 

[Timmy390]

Too much pressure will overpower the float in the carb as I understand it.

Tim

 

[hyghlndr]

I have used this on several, not super quiet but good reliability. No regulator needed.

https://www.summitracing.com/parts/crt-p4070/overview/

 

[Rustytruck]

excessive pressure will cause the fuel in the float bowl to over flow on really bumpy trails if you travel off road. Bouncing the float up and down, the fuel passes the needle and seat. the higher the fuel pressure the more that bypasses. The longer you bounce around the worse it gets.

 

[Eoth]

I understand the need for proper PSI. I am amazed on how few options I have in fuel pumps that don't require a regulator.

 

[SavageBurro]

I use the Carter P4070 pump rated for 4-6 psi without an external pressure regulator. It's never a bad idea to run a pressure regulator after the pump with a return line to the tank but lots and lots of guys run this Carter P4070 without one with good luck. Works great for me... haven't had a single issue with fuel pressure. The pump is a bit noisy, especially at first startup. Using the rubber isolators for mounting help a bit. I've only had it on there a year or so and had never used one prior, so I can't speak first hand for longevity but from the interwebs research I did its a very reliable unit.

 

[ntsqd]

I've got a couple P4070's in use on various machines. They all came from the dyno I used to work at where we used them to move diesel fuel around. I wouldn't hesitate to use one in a low pressure application.

If you do go with a regulator I'd strongly suggest a by-passing type with a return line. These keep the fuel circulating so that you don't end up with a hot slug of fuel in the supply line. Putting the supply line under greater pressure is good for defeating vapor-lock, but putting it under pressure and circulating it is another step in the right direction.
At that point you might think that you can run any pressure that you want, but you'd be wrong. Most regulators have a max psi input that they can regulate down from. I'm using a Holley on the Valiant that the Holley rep on the phone said wasn't intended for that much pressure, but seems to be working fine with a Walbro TBI pump (~15-17 psi). I'm quite sure that it would not work with an SEFI/TPI pump (40+ psi).

 

[RODRIG3911]

I use the p4070 that others mentioned and its great!

 

[Eoth]

Well that answers that.... p4070 on order. Thanks guys!

 

[figo40]

I have used this on several, not super quiet but good reliability. No regulator needed.

https://www.summitracing.com/parts/crt-p4070/overview/

I run the same one, no problems, runs great, edelbrock preformer manifold and a 1406 carb.

 

[bronco loco]

Another vote for p4070, works flawlessly with my Holley street avenger.