Fuel system advice.
 

I need some advice on a new fuel system for my build. Carb motor, I can find info online about how much fuel I need to push in a fuel injected application, but not carb'd motor, especially one at high elevation where I boat. I boat between 4500-7000 feet in elevation. May take it to Lake Powell later this year or next year which is around 3500 feet in elevation. I don't know if a mechanical fuel pump will support my power levels which should be around 550-650hp depending on where I boat.

Mechanical fuel pump? Easy.

Holley 130 GPH marine. You'll need a regulator (I don't think it comes with one). We're using this one on a 700 HP blower setup without even a care.

https://www.cpperformance.com/p-1328...ock-chevy.aspx (price is the same on CP/Summit/Jegs/Etc)

Clay Smith would have been a great pump, but I don't think they're available any longer.

That's a great pump. I'll get an adjustable regulator. Since it's mechanical I'm assuming it doesn't need a return line to the fuel tank?

Quick Fuel 30-175QFT 175 GPH Bypass Billet Electric Fuel Pump (holley.com)

I ran this feeding two 850 cfm carbs when I was carbed....still have it in a box actually if you're interested...obviously it's electric but has a built in regulator so it was pretty compact which I liked. It was on a 468 with a 8-71 probably 750ish hp

I’m running a Weldon A600 fuel pump through the carb to a Weldon return regulator. The return is plumbed to the fuel fill.

Last time I spoke to Clay Smith they said Holley bought the rights for the pump. Not sure if Holley produces it any longer. Clay Smith was still repairing them last time we spoke. They rebuilt mine with 15 psi springs. Running an Aeromotive regulator with it. 7.25 psi all the time. Very happy with the setup on a 500hp BBC.
https://cimg0.ibsrv.net/gimg/www.off...8fb0408d13.jpg

This is the one going on mine.

Baker, no regulator needed. 1/2" NPT inlet/outlet to move a lot of fuel.

https://teaguecustommarine.com/1-2-n...let-fuel-pumps

$340 for mechanical pump? Ouch.

I tried that Baker pump on a 900hp engine and it didn't work for me. It would be down to 3psi at WOT. They sent me the 15psi springs for it so I plumbed it with a return regulator and although it kept the pressure up, you could see every stroke of the pump on the pressure gauge(needle moving so fast it was a blur) and kept destroying gauges in just a few minutes of run time. I ditched the whole mechanical pump setup and installed a Weldon electric pump and went trouble free boating. I spent a lot of time, trouble and money trying to keep it simple with a mechanical pump. I wouldn't do it again. Weldon for the win.

Only problem with going electric is wiring it to a bypass or switch so when you turn the key to the on position it doesn't start pumping fuel. putting in a regulator and return line to the tank is a piece of cake. For those of you that went electric, how did you wire so it wouldn't activate with the key in the on position?