fuel line questions

[Fox_84]

I have to change out the fuel lines in my 93 gt, feed and return. Right now the car has the stock 302 with no work at all. In the near future it will have a built 302 possibly blown but regardless, the goal is 500hp, maybe a little more. Since I have to replace lines now, do I go ahead and upgrade them to fit my needs later or will that be a mistake for now? Do I go with bigger sized lines and if so, I want to go with stainless steel braided lines so I dont have to bend them to fit like steel lines. Or do I need to stay with steel lines and just work at bending them to mount to factory brackets? If I can go bigger and better now to fit my needs for later and the car still run fine, what do I need to do and where do I get the parts? I am looking to do this right, but would like to save the money of having to replace lines now and also replace later after the engine build. Thanks in advance.

 

[jrichker]

The SS braided hose is $3.60-$5.00 per foot plus fittings. Possible hose sizes are -6 (3/8"), and -8 (1/2").

http://www.amazonhose.com/default.asp for hose, fittings and complete hose assemblies

See http://www.aircraftspruce.com/catalog/mepages/alumtube_2024.php for aluminum fuel line tubing.

The 37 degree flare is the same flare angle as the AN fittings. Slide the flare nut, and then the flare cup on the line and flare away. Don't try to cheat and use a 45* automotive flare tool, you'll get leaks.

Any shop that makes hydraulic lines can flare the tubing and provide the fittings for a small price if you don't have access to the proper tools. Any industrial supply store will have a 37 degree flaring tool for sale. They tend to be somewhat expensive - $75 or more
http://www.mcmaster.com/ctlg/DisplC...319476238962&ScreenWidth=800&McMMainWidth=588

or
http://www1.mscdirect.com/CGI/NNPDF...H&PMT4NO=6174876&PMITEM=74787516&PMT4TP=*LTIP

 

[Vipersix]

1/4" ID is plenty large enough for 500 bhp. You won't be experiencing any performance losses as long as you have a pump which has adequate volume/pressure ratings for your setup. The lines are basically a moot point until you get to the point of limiting the volume for high power ranges.

 

[Fox_84]

So i can go with bigger than factory lines just so long as I put a larger pump, even with my stock engine until I go larger? What size line/pump combination should I go with to handle 500+hp? Should I go with stainless steel braided rubber hose or steel lines? What setup all together would be the best to go with?

 

[Fox_84]

Anymore ideas on what I should do? Any help at all???

 

[Vipersix]

You don't necessarily have to increase your pump simply because you get larger supply lines. Think of your fuel system as a water hose sticking out the side of your house. If you open the *****et half-way, you might get 5 gal/hr which we'll equate to a stock fuel pump. Let's say your injectors require 4 gal/hr at 80%. By simply replacing the hose with a larger diameter line will not change the needs of the injectors, they still need 4 gal/hr and are receiving 5 gal/hr.

Where people get into problems is by having too SMALL supply lines. The pump is capable of providing 5 gal/hr at our required pressure and the injectors only require 4 gal/hr but the tiny tube can only provide 3 gal/hr. Therefore, as long as the pump you currently have is capable of providing enough fuel for your needs you won't have to get a new one.

A n/a 500 bhp engine should require injectors somewhere in the realm of 35 lbs/hr @ 80%. At that rate, you're looking at peak volume to be 35 gal/hr (130 lph). So you'll need to get yourself a pump which will flow at least 35 gal/hr at the pressure you intend you run. Don't forget that pump volume decreases as pressure increases.

Beyond that, it doesn't matter what type of fuel line you use. If you go with solid lines, don't forget to periodically include rubber fittings to allow for vibrations.