How much fuel can fuel lines support - looking at -10AN(.62)

SuperRunner · Post by **SuperRunner** » Thu Jan 03, 2008 7:32 pm

I am trying to find out how much fuel my lines can support. I think I may need to upgrade yet again.

I am running -10AN lines or .625, but I am sure that has been restricted to .5" in some places. My fuel pressure is 43psi, but will probably up it to 55psi. Anybody know of a calculation I can use?

hotrod · Post by **hotrod** » Thu Jan 03, 2008 11:01 pm

In pressurized fuel systems a -10 line will move a ton of fuel. Unless you are feeding an aircraft engine or a AA fueler that is probably good enough.

Eaton has a chart to figure fuel flow capacity of its lines in their catalog. It is intended for oil so it is very conservative for gasoline due to its lower viscosity.

viewtopic.php?t=2471&highlight=eaton

I will add a link as soon as I find it stand by.

Well they reorganized their rather poorly organized website so it took a while to find the chart it is on page 357 of this industrial hose catalog segment.
http://hydraulics.eaton.com/products/pd ... 43-380.pdf

Larry

Ron C. · Post by **Ron C.** » Thu Jan 03, 2008 11:21 pm

If you have varying restrictions and you need an accurate calculation (like for a blown application) you need to do a flow test on the actual line or system. Formulas can be way off.

I usually do a limited time test, like 15 sec or 30 sec and measure the actual flow in a container at the pressure required.

You'll sleep better at night knowing actually what it really is.

Blessings.........Ron Clevenger.

bill jones · Post by **bill jones** » Thu Jan 03, 2008 11:38 pm

-I did some math using flow from Hilborn nozzles as follows:

1-.035" Hilborn nozzles flow approx 97pph at 45psi.

2-eight .035" nozzles flow 776PPH--which will support about 1550hp on gas.

3-one .035" nozzle is .0009621 square inch area.

4-eight .035" nozzles equal .0076968 square inch area.

5-being conservative on hose and fittings with a diameter of .500" equal .1963 square inch area.

6-hose and fitting square inch area of .1963 divided by .0077 equals 25.5.

7-this means the half inch hose is 25-1/2 times larger than eight nozzles sized to make something like 1550 hp---so it looks to me like #10 hose at 45psi is plenty big.

8-BUT you have to take into account the G-force against the fuel inside the hose----the height the fuel has to be pumped etc---and I didn't take any of that into account.

SuperRunner · Post by **SuperRunner** » Thu Jan 03, 2008 11:55 pm

Seems my -10AN line will be plenty, as it can handle 600gph. I am looking to move at most 300gph. But I should definatly test it for restrictions. I am using all radius bends, so that should help. My pickup tube may need to be increased a little. It is -10AN as well. I will need -12AN for sure. I will be running E98, so I need quite a bit of volume.

BLACK BART · Post by **BLACK BART** » Fri Jan 04, 2008 5:07 am

SuperRunner, your #10 line is most likely not .625" inside diameter. If you look on the Aeroquip, Goodridge, or XRP web sites you can find the dimensions for the various hoses. Some of the push on hose is made to actual sizes such as 10/16" = 5/8" or .625", but most of the steel braided stuff is smaller on the inside. For instance the Aeroquip braided stainless AQP hose is listed at .560" for the #10 size. Worse yet, the fittings are even smaller. For a #10 adapter they list the inside diameter at .480" which is a lot smaller than the 5/8" we usually associate the #10 line and fittings with.

I don't know what you are running or if your line is big enough or not, but I do know that if you are running a stainless braided line you may be shocked at how small the inside size actually is compared to what you thought it was.

Regardless of size, I think flowing the system is a smart move. Good luck, CJ

SuperRunner · Post by **SuperRunner** » Fri Jan 04, 2008 10:52 am

The stated ID of the hose is .625, but being rubber line, I am sure that varies.

Bill, yeah, the length of the hose and gravity aren't considered in those calculations. And I will be running ethanol, so I need about double the size needed for race gas. I was running 860cc injectors at 55psi with -6AN lines, and I had the injectors at 100% duty cycle, and would begin to run lean at 18psi with E85. Since then I have upgraded my whole fuel system, and have 1600cc injectors. Problem is my transmission doesn't hold long enough for me to tune.