Basic Fuel flow question on hose diameters
Thread Starter
Joined: May 2011
Posts: 8,485
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From: Wichita, KS
Basic Fuel flow question on hose diameters Will an equal length -12AN flow more/less/similar to 2 -6AN lines?
I find one site that states flow is directly proportional to the ID of the lines. Suggesting that 2 -6AN would flow similar to 1-12AN.
Yet I find another that says Area = Pi * Radius^2 which would indicate that the -12 has a greater area and flows more than than 2 -6's?
I find one site that states flow is directly proportional to the ID of the lines. Suggesting that 2 -6AN would flow similar to 1-12AN.
Yet I find another that says Area = Pi * Radius^2 which would indicate that the -12 has a greater area and flows more than than 2 -6's?
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Do the math- double the diameter, quadruple the area. 2' diameter pizza (1' radius) vs. 4' diameter pizza (2' radius). Area = pi x square of radius.
2' pizza - 3.1416 x 1 x 1 = 3.1416
4' pizza - 3.1416 x 2 x 2 = 12.5664 (4 x the 2' pizza)
2' pizza - 3.1416 x 1 x 1 = 3.1416
4' pizza - 3.1416 x 2 x 2 = 12.5664 (4 x the 2' pizza)
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Joined: Nov 2003
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From: Norn Iron
Will an equal length -12AN flow more/less/similar to 2 -6AN lines?
I find one site that states flow is directly proportional to the ID of the lines. Suggesting that 2 -6AN would flow similar to 1-12AN.
Yet I find another that says Area = Pi * Radius^2 which would indicate that the -12 has a greater area and flows more than than 2 -6's?
I find one site that states flow is directly proportional to the ID of the lines. Suggesting that 2 -6AN would flow similar to 1-12AN.
Yet I find another that says Area = Pi * Radius^2 which would indicate that the -12 has a greater area and flows more than than 2 -6's?
Although I did see someone post ages ago that just because a pair of hoses may calculate as the same area as a larger single...does not mean they flow the same. Can't recall his reasons though...might have been due to surface friction etc within the pipe ?
Interesting calculator here...Certainly putting numbers into this, a pair of small hoses flows nowhere near a single larger hose at the same pressure usng -6 and -12 as comparisons.
https://www.copely.com/tools/flow-rate-calculator/
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Thread Starter
Joined: May 2011
Posts: 8,485
Likes: 1,028
From: Wichita, KS
Don't go by hose sizes....measure the ID of the actual hose fittings, which are always smaller than the hose sizes, and all hose makers are not the same, nor are their fittings.
Although I did see someone post ages ago that just because a pair of hoses may calculate as the same area as a larger single...does not mean they flow the same. Can't recall his reasons though...might have been due to surface friction etc within the pipe ?
Interesting calculator here...Certainly putting numbers into this, a pair of small hoses flows nowhere near a single larger hose at the same pressure usng -6 and -12 as comparisons.
https://www.copely.com/tools/flow-rate-calculator/
Although I did see someone post ages ago that just because a pair of hoses may calculate as the same area as a larger single...does not mean they flow the same. Can't recall his reasons though...might have been due to surface friction etc within the pipe ?
Interesting calculator here...Certainly putting numbers into this, a pair of small hoses flows nowhere near a single larger hose at the same pressure usng -6 and -12 as comparisons.
https://www.copely.com/tools/flow-rate-calculator/
Looking at that fluid flow calc. It seems the larger line is leaps and bounds better?
-6 hose at 12 ft and 3 bar = 5.9 lpm 354lph (x2 708lph)
-10 hose at 12 ft adn 3 bar = 32.76 lpm 1965lph
-12 hose at 12ft and 4 bar = 57 lpm 3420lph
using 3/8 for -6 or 9.53mm.
using 5/8 for -10 or 15.88mm
using 3/4 for -12 or 19.05mm.
Feel like I did something wrong.
Reason I ask is guys seem to be getting more out of these AEM380 pumps by running separate -8 lines from each pump to each rail. Than guys merging -8 lines into a single -10 or -12 line. I'd think it would be the other way around.
This guys at a steady 13.5v and trapping 182 in a 3000lb setup. Yet others run out MUCH sooner with dual AEM's and "Y" in the system with a single larger line.
Last edited by Forcefed86; Oct 26, 2020 at 01:21 PM.
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Joined: Nov 2003
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From: Norn Iron
The numbers from the calculator do seem far too dramatic. But presumably there is some science/physics behind them.
Unless you were making a **** ton of power on methanol or something though...-12 feed line does seem a tad excessive.
Although I would do a -12 from tank to pump as it's just a gravity feed, via a suitably large filter for each pump.
Unless you were making a **** ton of power on methanol or something though...-12 feed line does seem a tad excessive.
Although I would do a -12 from tank to pump as it's just a gravity feed, via a suitably large filter for each pump.
On The Tree
Joined: Mar 2010
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From: London,Ontario,Canada
I also remember reading somewhere that hard line flows more than rubber in same size. Something about friction. So I would guess a lined rubber hose would flow more than pure rubber hose. So how much difference? Anyone else care to enlighten us?
Aleck
Aleck