Fuel system setup
 

How much HP would this setup support.

1/2" tank pickup, 5/8" fuel line to Fram racing fuel filter, #10 line from filter to 1/2 NPT inlet on Holley 130 GPH self regulated six valve mechanical pump. 1/2 NPT pump outlet to #10AN line going up to four port fuel block. Then #6 line to each carb bowl. Dual 850 Holleys on top of a 420 B&M blower.

Trying to keep a simple fuel system but with large lines and no 90* adapter fittings.

not an expert but I would say far more than the 420 blower will make.

Your GPH will only flow as much as your smallest line. I think the 1/2 is good for roughly 130 GPH free flow and here s a quote explaining how to calculate what you'll get. You can play with the numbers in the formula below.


The average advertised weight of a gallon of premium fuel is 6.34 lb/gallon.
Brake Specific Fuel Consumption or B.S.F.C.
Brake Specific Fuel Consumption or B.S.F.C. is the amount of fuel required to produce 1 HP for 1 hour. This means that an engine with a B.S.F.C of .5 will burn 1/2 or .5 lbs of fuel to produce 1 HP for one hour. Determining exact B.S.F.C for a specific engine is complicated and requires an engine dyno.
Based on industry standards the B.S.F.C for:
Normal Aspirated Engines is .45 - .55
Supercharged Engines is .55 - .60
Turbocharged Engines is .6 - .65


need to calculate fuel required:
Target Hp * B.S.F.C. = Fuel required in lbs/hr
600 *.56 = 330 lbs/hr
Most fuel pumps flow rate is advertised in gallons per hour:
Lbs/hr / fuel weight per gallon = gal/hr
330 / 6.34 = 52 gal/hr
but remember pump losses, and a fuel pressure regulator and a return line fuel feed system designs flow requirements ?

thats almost the same setup as my cat has,and they are 950hp at 6200 rpm,no need to worry,wlll work great for your power.

Thanks guys. Trying to keep it simple. I have a few extra of these six valve 1/2" in/out mechanical pumps for spares. I bought two brand new ones last spring.

As much as your setup will make:drink:
That will do fine for any amount that 420 can muster. Good luck.
Eddie

How do you guys feel about electric fuel psi gauges? For some reason, i just dont trust them. I was thinking of adding in a fuel psi switch, that will trigger the alarm and LED light should the fuel psi fall below say 5psi?? :bigbird:

Fully agree!

I have an LED on the dash that blinks if psi drops below 4psi and I have mechanical gauges mounted on the engine. You can see them in the big plate that holds my MSD,coil, etc.

http://i69.photobucket.com/albums/i4...b/5fb969b6.png

I have a similar setup on my boat, my concern is sucking through the filter. Is it better to pull through the filter or push through it? I have been thinking about using a mesh prefilter to the pump and then push through my final filter. I am using a WIX 3522 filter which has a built in water separator and has twice the filter area of the standard Fram. Interested in any opinions, I'm running about 700hp through the Merc seawater pump, and I know I'm at the limit of this setup.

The electric gauges are notoriously inaccurate. However, they usually always hold the same inaccuracy. Even though they aren't usually correct, they should read the same all the time. Your best bet is the set the pressure with a mechanical gauge first.
Eddie

This came from a boat manufacturer and was told to me. "It is against Coast Guard regs to send pressurized fuel through a spin on, water seperating filter." I'm not sure if what they say is true, but it does make some sense. The filter does collect water and is made from steel, so it is possible that it could rust from the inside out. This could cause a pinhole that would spray fuel at ??? psi all over the bilge. In the case of an efi engine, it could be as much as 80 psi before the regulator. Obviously, this could be dangerous. If it happens on the suction side, then it will just lose it's prime.
I've never had an issue with a properly sized fuel pump and hose setup pulling through a filter. If everything else is correct, it should work just fine pulling.
Eddie

That would make a LOT of fuel systems illegal. Most engines I see have a mech pump pushing through the spin on filter. Hmmmmm?

The merc setup that has a mech. pump driven off of the seapump pulls it's fuel from the filter first. On every merc engines that I can think of, the fuel goes into the filter first.
Eddie

My 1993 502 mags went; wallet>tank>mech pump>spin on filter>carb
My 2002 575SCi's go; mortgage>tank>mech pump>spin on filter>elec pump>threaded filter>TBody

Both had/have the sea pump/fuel pump set ups.

All Merc 496's w/ Gen II fuel system have the filter 'pressurized' by the lo-pressure electrical fuel pump.

the coolfuels send pressure from regulator back to spinon filter, that is purpose of black plastic cover. it is intended to divert spray fuel down, towards bilge to help prevent spray fire(blow-torch).