Fuel pump? What's everyone running?

[Roppa440]

I also have a 530hp engine with HV Carter mechanical pump and 3/8 lines to a stock six pack hard fuel line. I ran high 11s like that.

I just upgraded the engine slightly with about another 20-30 HP so i upgraded the fuel lines too but have yet to test it to see what the car will do now.

I have just fitted a 1/2inch sender (was 3/8) and run 1/2 inch all the way to the pump.
At the pump I have opened out the inlet/outlets to take -8AN fittings and run -8 line to a large filter and regulator mounted behind the grille for cooling.

It then runs -8AN to the six pack where it branches into 3x -6AN lines that go directly to each carb.

I don't think I will have fuel delivery problems but i will let you know if I do.

PS
I hate electric fuel pumps and would only use one if really needed.

[cuda-cable]

I'm running a Holley mechanical pump from Summit, takes the 3/8" lines, bolt on and is chromed......works fine on my 340 feeding a 600 carb.....dk

[IMNCARN82]

I'm running a Holley mechanical pump from Summit, takes the 3/8" lines, bolt on and is chromed......works fine on my 340 feeding a 600 carb.....dk

I got the same  Holley mech. HV pump. chrome 340 +.030,  650 carb.    No problems    But I'm going electrical someday.

[carguybradd]

In my Duster with a built 340 I'm running a Holley black pump, Fram HP-1 filter, -6AN lines, and an adjustable pressure regulator at the carb. I also made my own 3/8" tank pick-up to replace the 5/16" stock unit. It's overkill for a small block, but I was going to run nitrous at one point and wanted to eliminate any possibility for the motor to go lean.

The pump is somewhat noisy unless the engine's running, at which point you can't hear it anyways. 
I also used existing factory wiring from the original rear window defroster/blower-motor I removed, so wiring it was a snap. Routing the undercar lines was a PITA, though. Don't think I'd do it again...

[Grancoupe]

Everything has its positives and negatives. A lot of negatives about electric pumps which I advocate. Every modern day car in the world is running them.
Consider if the car sits for a while and the mechanical looses its prime or the line drains back your not cranking the motor for 5 minutes while the line fills back up. Just turn the ignition on and listen to the the fuel line prime up. You will hear the fuel pump make a different sound when the pressure hits 7 or so.
Another thing worth thinking about and I had this happen to two different cars. The seal between the pump the the level ruptured and filled the crank case with gas. I've also had a few leak outside the engine which is a safety hazard.

[Roppa440]

A few negatives on the electric pump side are worth noting though.

In the event of a bad crash an electric pump will continue to pump gas even when the engine has stopped. I have nightmares about burning to death in a car since a friend did many years ago.

Modern cars do indeed have electric pumps. But they seem 100x more reliable than the ones made for the aftermarket because the guys I know using them on their Mopars have all had a break down at some point due to the pump failing.

Many Mopars using stock Mopar alternators and stock wiring have issues keeping the battery charged at 800rpm or less when idling in traffic. You can't go anywhere in the UK without encountering at least one traffic jam on the way. The problem is worse if you add the extra load of headlights, electric fan, and an electric fuel pump. If your voltage drops below 14.5 volts at idle you should think twice before adding extra electrical equipment.

It is a myth that powering something electrically will free up horsepower at the engine. In reality it uses less HP to drive something mechanically than electrically. In engineering you never get something for nothing and there are always losses when converting one form of energy into another.

[6packCuda]

A few negatives on the electric pump side are worth noting though.

In the event of a bad crash an electric pump will continue to pump gas even when the engine has stopped. I have nightmares about burning to death in a car since a friend did many years ago.

I wire in an oil pressure safety switch with the elec. pump for that very reason. If the engine dies, the fuel pump shuts off.

[Grancoupe]

My entire system is routed in Stainless braid and Earl's fittings. The system is basically bullet proof to crash damage. the stuff holds up the aircraft specs. If I were in an accident that compromised my fuel system's integrity i don't think I would be around to worry much about if the pump is running.
Regarding load. I thought it was the contrary about parasitic load. Isn't that why everyone is paying money for electric water pumps. electric fans, etc?

[todd383]

What does it do in the 1/4 mile?

Hey 71chally416 never took it down the 1/4, this summer will be the first time out in 6 years, but i drove it with my friends dealer plate and its fast, with better gears proably high 11s

[71chally416]

383's need gears 

[nivvy]

It is a myth that powering something electrically will free up horsepower at the engine. In reality it uses less HP to drive something mechanically than electrically.

I disagree with that.....

[the_engineers]

I disagree with that.....

I would think that the only way it would take more HP to drive the extra 5 Amps that an average Elec Fuel Pump requires is if the charge produced by the alternator is already being completely consumed.  Does anyone have any dyno tests featuring electric vs. mechanical?

[Roppa440]

I disagree with that.....

Thought that would get a few comments.

OK so some equipment might use less energy when electrically powered. But some will not. It depends on if the mechanical losses are greater than electrical.
Take the fan for example. Most big electric fans use more HP than a stock fan and don't even work as well in a lot of cases.

The energy to drive anything has to ultimately come from the engine. Every time you change energy from one form to another there are losses. You cannot escape that. Nor can you create energy from nothing.

[the_engineers]

I agree that you lose efficiency when converting from one form of energy to another, but I think we're talking apples vs. oranges in this case.

If there was less friction in the actuation of the mech pump and there was not a "surplus" of power being provided by a properly running alternator, I would agree with your theory.

Somewhat related, is anyone using a return line with an electric pump?

[Roppa440]

I am not sure that there is a "surplus" of power from the alternator. It only supplys the current demanded of it. Voltage is maintained at a constant. The mechanical energy required increases with current demand.

I doubt there is much in the way of friction losses on a mechanical pump.

If it takes, say 100 watts, of energy to power something like an electric pump. Where does that come from? The engine has to drive the alternator to convert 100 watts of mechanical energy to 100watts of electrical energy. But suffers losses as a result of internal resistance and resistance in the wiring.

Now if you are saying those losses are less than the losses due to friction then you are right. But I am not convinced they are.