Fuel Line Size - 5/16 and 1/4 Return Lines

[Padawan]

All,
Quick Question:

Do I need to run 3/8 fuel lines or will the 5/16 work?

I'm most likely using this post filter https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/filters/efi_filters/parts/162-550

Holley Sniper - 550-510 https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/factory_refurbished_-_sniper_efi/parts/FR550-510

302
E303 Cam
AFR 165 Heads
In tank fuel pump 190lph from Breeze

Guessing around 320hp

I just don't want to starve the engine.

Everyone I've spoke to has been running 3/8 fuel lines but they all have had 347 or bigger engines


Love to hear your thought s on fuel line size...

Thanks

[phileas_fogg]

I use a 5/16" feed and 1/4" return for my Holley Terminator system. It feeds my 302 with E303 cam just fine.


John

[ggunter]

If you see how much fuel squirts out of a 5/16 line at 58 psi you could empty a 15 gallon tank in just a few minutes. You won’t starve your motor. If your running a drag car that’s another story. You need volume.

[cv2065]

I ran 3/8" all the way around. I said...why not...I'm already down here.

[edwardb]

The 5/16 and 1/4 inch lines will be fine for your engine setup. Easily.

[rich grsc]

I ran 3/8" all the way around. I said...why not...I'm already down here.
You don't have a near stock 302.:p

[cv2065]

You don't have a near stock 302.:p

That's true Rich! :)

[Padawan]

That's true Rich! :)

I'll run the lines 5/16 line and 1/4 as the return that came with the kit...now just need to figure out the adaptors. AN6...ect... all greek, but I'm figuring it out...

Thanks...

[BradCraig]

I’ll respectfully disagree with some of the others, Holley is very clear about recommending min 3/8 supply and return for the Sniper. So easy to run now, so why not? If you run the smaller stuff, make sure to verify pressure with a gauge and as long as you are within range you should be good. Now, having said that, I am running 3/8 supply and 5/16 return on my Camaro (5/16 was original fuel line) and my plan was to rip out the 5/16 if pressure was too high. :-)

[Papa]

I'm running -6AN lines for both supply and return with 3/8" ports for both on the pump hanger. At this point in the build, it's easy to run what the Sniper wants.

https://thefactoryfiveforum.com/attachment.php?attachmentid=84613&d=1524423650

Recommended hanger:

https://www.promracing.com/high-flow-fuel-pump-hanger-for-1986-1997-mustangs.html

[NAZ]

AN fuel line sizes are in multiples of 1/16", therefore, -8AN is 1/2" nominal (ID for hose & OD for tubing). Here's a good explanation on how to properly size fuel line and why it matters if you're plumbing for a carb or FI: https://premierwd.com/fuel-system-knowledge-series-fuel-line-size-vs-pressure-drop-presented-by-fuelab/

https://help.summitracing.com/app/answers/detail/a_id/4879/~/what-size-fuel-line-do-i-need%3F (https://premierwd.com/fuel-system-knowledge-series-fuel-line-size-vs-pressure-drop-presented-by-fuelab/)

[RBachman]

I just installed one of these yesterday. Runs great. But read through the directions very carefully before you install it. All of them, not just the quick start thing. In fact, forget about the quick start thing and read the downloadable full manual: https://documents.holley.com/199r11031r.pdf

Regardless, Holley recommends 3/8" lines and 60-pisg at the inlet. I'm using a Holley HP in-tank pump. I have the Sniper controlling the fuel pump, the fan, and a secondary temperature alarm.

[cv2065]

I have a carb now, but plumbed fuel lines that would make it easy to go FI in the future if I wanted to.

[BradCraig]

I just installed one of these yesterday. Runs great. But read through the directions very carefully before you install it. All of them, not just the quick start thing. In fact, forget about the quick start thing and read the downloadable full manual: https://documents.holley.com/199r11031r.pdf

Regardless, Holley recommends 3/8" lines and 60-pisg at the inlet. I'm using a Holley HP in-tank pump. I have the Sniper controlling the fuel pump, the fan, and a secondary temperature alarm.

Great point, why Holley doesn't include the full install manual in the box I'll never know. Most Sniper issues are caused by people not RTFM.

[RBachman]

Great point, why Holley doesn't include the full install manual in the box I'll never know. Most Sniper issues are caused by people not RTFM.

Exactly! Heck, if you're not careful those directions will show you how to quickly fry the ECU. The complete manual is a necessity, and why Holley doesn't include a copy is incredibly stupid. Thankfully, I printed it off and read it before the Sniper arrived, and also read the installation recommendations from some of the Sniper forums. Glad I did, because the quickie instructions did not adequately warn you about a few things. Regardless, my experience thus far is that the Sniper is an excellent product when compared to FiTech. For example(s), they work, wiring is easier to install, Holley has incredible customer service, and greater reliability.

[Padawan]

Spoke with Dave at Factory Five....he said with the Holley Sniper to run 3/8 both ways...