Hi guys

I'm contemplating doing either a Small Block Chevy 350 V8, or 383 V8 over the winter.

I'm staying with the Carb setup, and I know that the mechanical fuel pumps on SBC's run @ low psi, vs electronic fuel pumps.

So my question is, what did you guys use for an intank fuel pump or in-line fuel pump?

Curious to know
Thanks
Dave M.

There are electric pumps that deliver in the 4-8 PSI with a proper regulator. I would be going that route if I was doing a carb deal.

Here is the old been around forever blue setup. http://www.summitracing.com/parts/HLY-12-802-1/

http://www.fastfieros.com

[This message has been edited by FastFieros (edited 10-06-2009).]

Use the stock Fiero in-tank pump with an external regulator. I'm using a regulator with a return line to the tank (since the line is already there).

quote Originally posted by couldahadaV8: Use the stock Fiero in-tank pump with an external regulator. I'm using a regulator with a return line to the tank (since the line is already there).

That's what I did as well when my car was carbed.

I am using the stock Fiero 4-cyl fuel pump and a Holley external fuel pressure regulator.
I used the set-up for my carb'd 3.4L and the same are now being used on my V-8 set-up.
The 4-cyl fuel pump is a little easier to control since it is only 9-12 psi and you need 5-7psi for a carb.
The V-6 is around 40 psi so if you use a cheap regulator you could get "pressure creep' and idle/low rpm's. Mallory makes a decent FPR when using the V-6 fuel pump. Make sure to get one with a return line.

The 3.4L had a Holley carb and it required the anti-slosh kit and I needed to keep the pressure up around 6 to 6.5 psi due to the side hung float bowls and single feed fuel line. On the V-8 I have an Edelbrock with the center hung float bowl which isn't as susceptable to sloshing like the Holley was and I only need 5.5 psi.

Sloshing can cause fuel starvation in turns and corners due to the transverse mounting of the engine/carb. Especially with the Holley. The dual feed Holley's are suppose to be better, But the 390cfm only came as a single feed. Even with the anti-slosh kit and the pressure bumped up I occassionally had some issues when racing on the road courses.

[This message has been edited by Oreif (edited 10-06-2009).]

If you use a block that works with a mechanical pump, and there are no clearance problems, I'd do that. Few fuel pumps match the reliability of the mechanical pump, and they pumped enough gas for hotrods for decades.

I'm using the stock GT fuel pump putting out about 50 psi and I run it through a bypass regulator.

http://www.jegs.com/i/Mallory/650/4309/10002/-1

The pump runs very cool, and very quiet because it is cycling well below its psi capacity. The regulator regulates the system down to 4-6 psi, doesn't creep, and is very stable. It delivers all the volume you need because the fuel pump is essentially idling.

Arn

God damn I love this Forum : D

Sounds like there are 2 options then:

1) to use an external FPR to bump the fuel pressure down with using the standard v6 in-tank Fiero fuel pump or other high pressure fuel pump.
2) to just use the mechanical fuel pump on the sbc v8 with the fuel lines right up to the tank.

Correct?

I plan on using the mechanical fuel pump on this 1974 monte carlo sbc 350 v8.

I've talked to guys that have tried using electric fuel pumps on sbc v8 carb setups and flooded their intake, top of the pistons, and even hyrdolocked their motor. All because of running too high of psi.

Crazy!

D

old school engine :P

Just because other guys have done it wrong, don't let that influence your decision.

The cost factor is the other factor. The mechanical fuel pump is cheaper.

That said, if you turn on the ignition for a couple of seconds you have instant pressure for startup. Also, the float system on the carb is relatively tolerant. The needle valve spring can take up to 8 psi (I checked with Holley) but is recommended for 6 psi.

I generally use 6 psi but have used less. One of the advantages of the bypass fuel regulator is the smoothness of the pressure. It stays rock solid. It does not fluctuate with rpm as many old school fuel pumps did.

I normally prefer old technology but, in this case, I have found the stock GT fuel pump with the right regulator is very satisfactory.

Nice to have choices eh?

Arn

The other advantage of the in-tank pump with external regulator is that you can pressure test the system and adjust the correct pressure without starting the engine; great for setting up a new system.

quote Originally posted by n_tensetuning: God damn I love this Forum : D Sounds like there are 2 options then: 2) to just use the mechanical fuel pump on the sbc v8 with the fuel lines right up to the tank. Correct? I plan on using the mechanical fuel pump on this 1974 monte carlo sbc 350 v8. I've talked to guys that have tried using electric fuel pumps on sbc v8 carb setups and flooded their intake, top of the pistons, and even hyrdolocked their motor. All because of running too high of psi. Crazy! D

The passenger axle runs right under the mechanical fuel pump location and under certain conditions (and depending on engine elevation within the chassis) the axle can wipeout the mechanical pump... and end your fun for the day. bmwguru posted a pic of this several years back. The lower the engine is in the chassis or the more you lower your car - the greater the possibility of mechanical fuel pump carnage.

I just finished my v8 and have done the 4 cly fiero pump with a mallory bypass regulator.I think archie recommends the 4cly pump for a carb setup.the first time i did not run a bypass but after reading from this site i went back and did the bypass hopefully to extend pump life

quote Originally posted by n_tensetuning: 2) to just use the mechanical fuel pump on the sbc v8 with the fuel lines right up to the tank.

Make sure if you go this way to remove the electric fuel pump from the tank and reroute the pick-up hose. Trying to draw thru the electric pump with a mechanical pump will not work very well. Originally I tried using an external fuel pump with a built in regulator and it had a hard time keeping pressure due to the draw-thru. Hence why I went to the 4-cyl pump in the tank. Unless you want to drop the tank, The easist way is to use the regulator Arn suggested.

quote Originally posted by couldahadaV8: Use the stock Fiero in-tank pump with an external regulator. I'm using a regulator with a return line to the tank (since the line is already there).

This is what I used too. You dont have to worry about fuel starvation, if I remember right Fiero uses the same pump as a Corvette.

I dropped my fuel tank, removed the internal fuel pump and ran a fuel hose from the top of the tank where it used to connect to the top of the internal fuel pump. I ran that hose to a sock-type fuel filter with a weight in it to hold it on the bottom of the tank. I then mounted an electric 6-12 psi pump in the same area as the stock filter. The pump has plenty of suction to initiate filling the pump from a dry hose, or running out of gas. I keep a fuel pressure gauge (electric) in the engine compartment where I can check the fuel pressure when I want to see what it is doing. That was for a 4 barrel on a LT1 that I converted to carbed. I have since installed the Holley ProJection 970 CFM fuel injection system and use the same fuel suction setup (no internal fuel pump) for the supplied 15 psi holley fuel pump. The stock return line is used to return excess fuel to the tank. I run a pressure gauge on it also to detect any restrictions. (My install is on my web page at www.v8-fiero.us)

I have used the suction-type pumping system on all my V8s and a couple of 2.8 cars that I got tired of dropping the tank to change the fuel pump. There are plenty of high pressure fuel pumps out there that can run inline and supply virtually any pressure you want or need. I installed one fro a Volvo that pumped 88 psi for the fuel injected Volvo so the stock 2.8 l pressure regulator brought it right down to stock pressure nicely for the 6 years I used it.