Fuel system setup questions

Posted By: DTT

Fuel system setup questions - 07/30/09 10:42 PM

Im in the process of doing my fuel system in my pickup. Its a pro street style vehicle. Im running -8 line for my feed. I have a fuel cell with a sump. My questions are:

1) The cell I have has foam, can I pull it out and still perfrom well on the street? What are the advantages to running it in a mostly street driven vehicle?

2) My return, should it be one size smaller or bigger than my feed? I have heard reccomendations for doin it both ways.

3) I have seen a lot of vehicles that have the return and/or the vent lines coming out of the cell ran in a coil configuration. Whats the reasoning for this?

4) Does anyone make a reducer that is also a bulkhead? Meaning I can go from -6 to -8 but doing it in a bulkhead through my bed floor.

Thanks a lot. Any other help is appreciated.

Posted By: sixpackgut

Re: Fuel system setup questions - 07/30/09 10:54 PM

what pump and regulator?

Posted By: MR_P_BODY

Re: Fuel system setup questions - 07/30/09 11:07 PM

Foam is there to control slosh, you have a sump
but dont have any baffles.... it MIGHT slosh enough
to suck air in a low fuel condition. If you go with
a larger return line(larger than the supply) you know
you wont ever have a pressure build up in the return
causing the regulator to act goofy. I'm not sure about
the bulkhead fitting. The coil of line is for expansion
in the tank, it will break a suction if one were to
develop

Posted By: DTT

Re: Fuel system setup questions - 07/31/09 01:04 AM

Quote:

what pump and regulator?

Mallory 140 pump. Mallory return style regulator.

Posted By: jamesc

Re: Fuel system setup questions - 07/31/09 02:44 AM

i don't see any reason to coil the return line. the reason for coiling the vent line is to prevent fuel from sloshing out the vent. as mentioned they recommend using a return line one size larger that the feed for the reason stated.

Posted By: RussW

Re: Fuel system setup questions - 07/31/09 03:17 AM

Quote:

Quote:

what pump and regulator?

Mallory 140 pump. Mallory return style regulator.

I'm using the same, I run # 8 feed to the carb and 3/8 steel return w no issues

Posted By: Ron Silva

Re: Fuel system setup questions - 07/31/09 06:00 AM

You can get a -8 an female to -6 an male reducer and then screw it onto a bulkhead fitting. But I doubt you can get it as one fitting. And here is a second way that is more compact. In stead of a Bulkhead fitting you can screw the reducer onto a -8 Male X -8 Male fitting. But it has to be tight to make it seal. So you would have to adjust the clearance or tightness on the sheetmetal that is passes through by adding washers or sanding the bottom of the reducer fitting as I already have on this one. It would not hurt if the whole thing was slightly loose on the sheetmetal as long as you backed it with a wrench when you tightened other fittings/lines onto it. Which you should anyways.

Ron.

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Posted By: Ron Silva

Re: Fuel system setup questions - 07/31/09 06:01 AM

the two fittings together

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Posted By: Cab_Burge

Re: Fuel system setup questions - 07/31/09 04:38 PM

Quote:

Quote:

what pump and regulator?

Mallory 140 pump. Mallory return style regulator.

I would call Mallory and ask them about using a return line on that pump, I don't think it has enough power to feed a good size motor at WOT and use a return style regulator

I hope I'm wrong

I have used that pump before on a stock stroke 440 with 906 heads and a single four barrel set up, 2 3/8 feed lines into two Fram fuel filters Y into the pump #8 line to the Mallory two port regulator they recommended, that set up was marginal on that combination

Posted By: DTT

Re: Fuel system setup questions - 07/31/09 06:38 PM

Quote:

You can get a -8 an female to -6 an male reducer and then screw it onto a bulkhead fitting. But I doubt you can get it as one fitting. And here is a second way that is more compact. In stead of a Bulkhead fitting you can screw the reducer onto a -8 Male X -8 Male fitting. But it has to be tight to make it seal. So you would have to adjust the clearance or tightness on the sheetmetal that is passes through by adding washers or sanding the bottom of the reducer fitting as I already have on this one. It would not hurt if the whole thing was slightly loose on the sheetmetal as long as you backed it with a wrench when you tightened other fittings/lines onto it. Which you should anyways.

Ron.

Thanks! I hadnt thought about that...Im gonna try it and see how it works.

Posted By: 62SAVOY

Re: Fuel system setup questions - 07/31/09 09:31 PM

Quote:

4) Does anyone make a reducer that is also a bulkhead? Meaning I can go from -6 to -8 but doing it in a bulkhead through my bed floor.

Maybe try these?

http://www.jegs.com/i/Earl%26%23039%3Bs/361/9892086/10002/-1

http://www.jegs.com/i/JEGS/555/100222/10002/-1
This one is kinda like what was shown in a earlier post.

Posted By: sixpackgut

Re: Fuel system setup questions - 07/31/09 09:42 PM

Quote:

Quote:

Quote:

what pump and regulator?

Mallory 140 pump. Mallory return style regulator.

I would call Mallory and ask them about using a return line on that pump, I don't think it has enough power to feed a good size motor at WOT and use a return style regulator I hope I'm wrong I have used that pump before on a stock stroke 440 with 906 heads and a single four barrel set up, 2 3/8 feed lines into two Fram fuel filters Y into the pump #8 line to the Mallory two port regulator they recommended, that set up was marginal on that combination

um, i'm over 700 hp and run a mal 140 and return style reg. -8an to and from with a stock tank and a 1/2 inch pickup. my fuel pressure is rock steady at over 130 mph

Posted By: Ron Silva

Re: Fuel system setup questions - 08/01/09 12:31 AM

I have a return style regulator that is DOWNSTREAM of the carb and does not kill any of the flow going to the Carb. It is a BACKPRESSURE Regulator and may work for you.

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Posted By: dartman366

Re: Fuel system setup questions - 08/01/09 12:42 AM

Quote:

I have a return style regulator that is DOWNSTREAM of the carb and does not kill any of the flow going to the Carb. It is a BACKPRESSURE Regulator and may work for you.

That is exactly how I did mine and used a comp 140 with -08 pressure and return and I have no issues running 10.00@131.00

Posted By: sixpackgut

Re: Fuel system setup questions - 08/01/09 01:01 AM

Quote:

I have a return style regulator that is DOWNSTREAM of the carb and does not kill any of the flow going to the Carb. It is a BACKPRESSURE Regulator and may work for you.

mine is the same way

Posted By: DTT

Re: Fuel system setup questions - 08/03/09 09:36 PM

Ive ran this setup for about a year without any real issues. I just decide to change my fuel cell and figured Id see if I should up the size of my return while Im at it along with any other changes....I am running a 3/8 return and 1/2 feed.... My regulator is the backpressure type too...

Should I up the size of my return to 1/2 (-8) as well???

and I still havent decided if Im going to remove the foam or not....... Thanks