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MASTERBrian · 03-29-2017, 02:21 PM

I've sort of asked this question before, but alas here I am again....

How do I know how many GPH I need?

Here's the deal, I have an Edelbrock 1405 Carb on a Performer Manifold. Stock Heads (with valve job), bored 60over, flat top pistons, isky 270/280 Mega Hyd Cam, HEI ignition, probably a few other things I'm forgetting. Machinist said expect about 300-330hp.

Based on other conversations, I have 2 choices:
1) Run a $135 Eddy Fuel Pump and be done (my problem is that if/when it breaks I don't want to be stranded and have to order another one of those. I prefer being setup to buy and run ANY pump off the shelf)
2) Run any off the shelf pump, realizing I'll likely spend about the same because then I need to run a regulater and a guage. (again, I like being able to just replace it on the fly if need be)

Here's the issue, I called summit about a week ago to get parts number, and start prepping for the purchase. The person I spoke with last time said, don't run the regulator/gauge, just buy the Carter Pump M4685, which puts out a max of 5.5-6.5psi and you'll be golden. He even asked HP and what was done with the engine, said I'll be fine it's a perfect fit and it's only $19 and excellent reviews. Free Flow Rate is 40gph.

I finally mounted the carb earlier this morning and buttoned up my list for the order. The person I spoke with this time said I'm crazy, that's not a big enough carb for the motor, he says I need to run a standard stock style pump, which puts out Max of 8psi and 110gph, of course Summit brand and about $55. He said absolutely don't run a regulator with a mechanical pump, if I want to regulate go electric.

I realize the Carter, somewhat goes in the face of my excuse for not going with the Eddy Pump, but seems like getting it might be easier.. I'll also admit, I like the $19 price tag and the 5 star reviews. First Rep seemed on his game, second one not so much. He also thought I needed to run a braided fuel line instead of my desire to run a solid line, his reason was engine flex....how will there be flex from Mechanical pump bolted to block up to carb, which is also basically bolted to the block.

In any case, I ended the call saying I needed to think this over.

I know I'm over thinking things most likely, but what gives....is 40 gph enough for a low 300hp sbc? Or is he right and I need to go more?

I'm hoping to get this stuff ordered today, so I can maybe get it by the weekend.

03-29-2017, 02:21 PM	#1
MASTERBrian Registered User Join Date: Jan 2017 Location: Wichita Posts: 639	Mechanical Fuel Pump Size?? I've sort of asked this question before, but alas here I am again.... How do I know how many GPH I need? Here's the deal, I have an Edelbrock 1405 Carb on a Performer Manifold. Stock Heads (with valve job), bored 60over, flat top pistons, isky 270/280 Mega Hyd Cam, HEI ignition, probably a few other things I'm forgetting. Machinist said expect about 300-330hp. Based on other conversations, I have 2 choices: 1) Run a $135 Eddy Fuel Pump and be done (my problem is that if/when it breaks I don't want to be stranded and have to order another one of those. I prefer being setup to buy and run ANY pump off the shelf) 2) Run any off the shelf pump, realizing I'll likely spend about the same because then I need to run a regulater and a guage. (again, I like being able to just replace it on the fly if need be) Here's the issue, I called summit about a week ago to get parts number, and start prepping for the purchase. The person I spoke with last time said, don't run the regulator/gauge, just buy the Carter Pump M4685, which puts out a max of 5.5-6.5psi and you'll be golden. He even asked HP and what was done with the engine, said I'll be fine it's a perfect fit and it's only $19 and excellent reviews. Free Flow Rate is 40gph. I finally mounted the carb earlier this morning and buttoned up my list for the order. The person I spoke with this time said I'm crazy, that's not a big enough carb for the motor, he says I need to run a standard stock style pump, which puts out Max of 8psi and 110gph, of course Summit brand and about $55. He said absolutely don't run a regulator with a mechanical pump, if I want to regulate go electric. I realize the Carter, somewhat goes in the face of my excuse for not going with the Eddy Pump, but seems like getting it might be easier.. I'll also admit, I like the $19 price tag and the 5 star reviews. First Rep seemed on his game, second one not so much. He also thought I needed to run a braided fuel line instead of my desire to run a solid line, his reason was engine flex....how will there be flex from Mechanical pump bolted to block up to carb, which is also basically bolted to the block. In any case, I ended the call saying I needed to think this over. I know I'm over thinking things most likely, but what gives....is 40 gph enough for a low 300hp sbc? Or is he right and I need to go more? I'm hoping to get this stuff ordered today, so I can maybe get it by the weekend.