Electric Fuel Pump Mounting

[rosco]

Anyone have any pictures on where to mount an electic fuel pump.

I want to add an electric fuel pump to augment the mechanical thats currently set-up on the vehicle. During a Dyno session, it was realized that I might be experiencing a fuel delivery problem since the air/fuel started out "fat" at about 10:1 then increased to 12.5:1 at final RPM range of 6,000.

If we tried to re-jet to compensate down low then I suspect a pretty lean condition at higher RPM; the thought was the current pump on the vehicle does not have enough suction for the hungry beast!

I'm running a Keith Craft 482 S/O with a Quick Fuel 950 Mechanical Secondary..

Note: Amnazingly, the car generated some good numbers; I can't wait until its all dialed in

Thanks in advance for your help!!

[eliminator]

Fuel System Plumbing...

My mechanical wont keep up with the 427 engine..about 505 HP, with a single 780 Holley. Anything over 5,000 RPM for any length of time (more than 8-10 seconds) it gets fuel starvation. So I just switch on the electric when I want to play hard and I am good to go. Those big blocks can suck up a lot of fuel, quick.

[sllib]

Rosco;
How big is your fuel line? Ford Muscle's web site has a good article about the need for bigger lines in cars with big engines. I installed a Barry Grant 220HR with 1/2" feed line and 5/8" return on my build and, while the car's not on the road yet, I talked with Grant on the phone and that's what he suggested for my engine. I don't have pictures to show, but I built a L-shaped panel and mounted it behind the pumpkin. The bottom is secured by the trailing arm plate and the top is bolted to the frame mount for the pumpkin. It bends back about 1.5" towards the pumpkin and that gives me plenty of room to mount my pump and a large cannister-type filter and still service the filter and rear end. If you're confused, imagine a cover for the back side of the differential that leaves the rotors in the wind on either side and you'll have it.
Bill Stradtner

[Aggressor]

10.0:1 is fat and 12.5:1 is'nt a lean condition unless you're draining your fuel bowls and sliding into a leaner situation. A 12.5:1 stoichiometric air-fuel ratio is considered the best power ratio. This is roughly 12.5 parts of air to one part fuel. That's what combustion engineers consider an excess fuel ratio and is intended to ensure that all the air is used to support the combustion process. Air is the oxidizer in combustion. Too many enthusiasts think that adding additional fuel beyond the ideal will create a richer mixture and yield more power. This doesn't work because you can only burn the fuel when you have enough air to support combustion. That's why engines make more power when you add a supercharger or nitrous--you're shoving more air in the cylinder so that you can burn more fuel. Regardless of the amount of air in the cylinder, it still requires a given ratio of fuel to burn. Add too much extra fuel, and power will decrease.

Modern head designs and hot ignition systems can run the power ratio into the mid 13's.

As Eliminator stated adding a backup electric pump is a good call for additional supply while playing hard at extended time at high rpm.

-Geary

[rosco]

Bill,

I have the standard 3/8" line from Unique....

Geary,

My fear is that if I leaned it at the lower RPM then I could really experience a lean at high 5-6K, perhaps + 13.5:1 ratio... I did not check the fuel bowls after the pull, maybe should have?

I'm looking at the Aeroquip Fuel Pump to support the mechanical.. Thanks Rick for the pictures; I'm sure I will use this set-up...

Gino