[baron_]

I'm trying to return this racecar to the street

has a holley blue pump
no return line, although the fuel cell has a provision for one (meaning there are two lines coming out of it, and only using one for the feed)


8AN braided line all the way to a 750 holley DP on a ram air IV 400
I'm getting 9 pounds of fuel pressure to the carb, which i figure is far too much?


Solution: Regulator?


where do ya'll normally plumb these? Put the regulator right after the fuel pump or up near the carb?

I'm guessing 9 pounds is far too much? Seems like i'm getting way too much fuel?

brand suggestion, plumbing solutions/thoughts, etc?


This is my first foray into electric systems
(i can't use a mechanical fuel pump - the eccentric is not there)

[Jagtec1]

You need to have a regulator with that pump, set to 7 psi. Get one from Holley, or anyone else. I'd put it up near the carbs...maybe on the fender liner or inner fender area.

[Motor Daddy]

Since you already have a provision for a return line, you should get a return style regulator. The return style will allow the pump to run much cooler, quieter, and will keep the pressure at a more constant pressure than a deadhead style regulator. I use the following return style regulator from Jegs. What's also neat is that the diaphragm is the same as a Holley 30cc accelerator pump diaphragm which can be obtained nearly everywhere, you just need to drill out the rivet.


The bottom one (555-15911) is the return style that I use. Just make sure you use a -8AN return line.
http://www.jegs.com/webapp/wcs/store...73419_-1_10323

[67cruiser]

BARON, i have the same problem right now with my stock tank, Don,t forget (i did) the return line must go back to the top of the cell not the bottom, my sump also has two lines, witch i was told for dual carbs. Also (i am learning also) the return line must be equal to or larger than the pick-up line. Im in the process of changing mine now because direction never stated this. Hope this helps you out!! Rich

[baron_]

interesting, interesting
I saw a fitting on the top of the fuel cell, but thought it was just a vent


the second fitting that i was talking about was in the sump, so maybe you're right...that that's for a dual carb setup?
Should i not run a return line to that sump plug? (i can see how that might not be good...pressured a little by the other gas) Run one to the top of the tank instead? (I never checked to see what size that fitting was)

i think the cap has a vent as well, though...so it might work to plump it into the top of the fuel cell into that fitting as shown (the way to do it?)

here's what the fuel cell looks similar to

So, what sort of regulator should i be looking into with this setup?

[KEN CROCIE]

A small worry!! Isn't the holley blue pump rated @ 14PSI? You may have a sick pump if output is only 9PSI

[baron_]

I haven't let it run more than 30 seconds...and it'll get to 9 psi pretty quick

it might make it up further if i let it run longer?

I'd like to think i was wise enough to figure that 9 psi was far more than I should have...so I didn't push my luck ...and figured the lack of a regulator would be the culprit

i just started it long enough to hear it run a little...and figured i should attend to details before i hurt something

[PLAY400]

Thought you dead headed the holley Blue pump into their conventional regulator with the bypass. Isn't the Black pump the 1 that needs a return?

[wheelspin]

Holley Blue pumps come packaged w/ a regulator, when purchased new. The Fram fuel filter in the pic is rated @ 90 gpm, which may present a flow restriction, depending on how fast your race car runs.

Les

[baron_]

should only be a 12 second car

a 461 was replaced with this 400
a good runner, but not a racer
ram air IV cam, 400, #16 heads with minor work, etc
enough to be fun, i hope

thanks for ID'ing the filter =]


So, mount a regulator up near the motor with an 8AN fuel return line to the top of the fuel cell?
'spose i'll just get the replacement holley regulator that would have come with it had i bought it new?

this?
http://www.jegs.com/webapp/wcs/store...10002_18328_-1
(max pressure version)

[Motor Daddy]

Originally Posted by baron_

So, mount a regulator up near the motor with an 8AN fuel return line to the top of the fuel cell?
'spose i'll just get the replacement holley regulator that would have come with it had i bought it new?

this?
http://www.jegs.com/webapp/wcs/store...10002_18328_-1
(max pressure version)

Be advised that is a deadhead style regulator. It will work, but has no provision for a return line, as it is not a return style regulator. Go back and read my previous reply and understand the difference between the two style regulators.

[RobbMc]

This regulator comes with two plungers so it can be used as a dead-head OR as a return. You can use it as a dead-head and then convert it to return later if you want:

http://www.robbmcperformance.com/pro...regulator.html

[baron_]

deadhead means?

I'm guessing that it means that it simply restricts the flow of the fuel? Like a block-off almost? (I could see how that might not have a great effect on the fuel pump)

While a return style would divert the gas through a return line?

a deadhead style would only have two lines...the fuel passes through it and gets restricted

the return style would have 3 different outlets...one in, one out and a return of the excess fuel?

[Motor Daddy]

Here's a link to get you up to speed on fuel systems. Pay particular attention to the operation and differences in both the deadhead and return style regulators.

http://www.centuryperformance.com/fuel.asp

[BILTIT]

Pretty much, yes.

[BILTIT]

''Nitrous systems are very sensitive to fuel pressure fluctuations. It is highly recommended that you run two independent fuel systems when using Nitrous (preferably with return-style regulators). Two small systems with small pumps, fuel lines and regulators are usually cheaper than one large system anyway. If you must use one large system, use two dead-head regulators installed in parallel, not in series. NEVER use two regulators in a system with a return-style regulator! Any fuel system with a return regulator must have only one regulator.''

This is interesting. I was going to run two reg's with one being a return. Guess i will buy another pump sooner than later.

[baron_]

last question, it seems:
(thanks for all the responses, i think i understand now)
and a good link: good reading

How reliable are these electric fuel pumps? Seems like they'd be working awful hard...almost all of the time

do they give out reasonably quick? years before one goes bad?


Ill probably go with the regulator @ jegs recommended by motor-daddy
the jegs store is about 3 minutes from me and i can have it for this weekend

[BILTIT]

I run a mallory 140 and have not had any problems yet (2 years). I will however be buying another as a back up.

They are no different than a fan motor i guess, they run a fair bit too and seem to last forever.

[LouisianaGuy]

Not trying to jack this thread, but a good friend and I were working on his 69 Mach1 and I knoticed that he had 10 Psi at his carb. I was wondering if that was too much.
He got a Manual fuel pump from Summitt that is supposed to be able to run with no regulator and no return, as I did not even see a porvision on the pump for a return.
So I take it we should back his pressure down to around 6 Psi Correct?
MAby a dead head regulator?
Mike

[baron_]

depends on the carb and setup, from what i understand

10 psi for a pretty strong race motor might be reasonable, a 429 CJ motor or something

but if it's a smallblock street motor....6 is probably closer

post more about his combo and these fellas would probably give a good opinion