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as a continuation of this thread: http://forums.tccoa.com/showthread.php?t=141698

yet deserving on its own of a new thread, I present to you another part of my tricked out build.

Working on making a custom fuel hat.

THIS is why "high flow" pumps can't seem to thrive in our cars, and I'm gonna prove it!

Exit of the stock tube of an MN12 pump hat vs a shiny bright 316 alloy, 1/2" OD, 0.035" wall, stainless steel tube:



Complete garbage I tell you! BUT, that's not the worst part....look at the beginning of that tube where the fuel pump actually feeds it....it's even smaller!










Anyone care to calculate the area % increase? I bet you'll be shocked. :eek:


Waiting on a couple of these...




:idea:
:wiggle:
 

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well id agree but guess what size hose is coming out of a 405 lph fuel pump its small even fore and other company use small hose if the pump isant any bigger i see know advantage

On a side not a single 405 on e85 on 10 psi on a 35 shot with a 11.2 air fuel ratio, not counting meth the pump had no issues on another note just at fore innovations has customers on gas making over 600 rwhp on gas on a boosted application with just one pump and stock lines and everthing

robert
 

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GM, I would seriously consider using one of these as a tubing bender.
I tried using what you have pictured above for 1/2" aluminum line, and all it would do is kink it.
I tried using a bender with a lever....still kinked.
Here is what works perfect with no kinks.
http://www.bonanza.com/listings/Yellow-Jacket-60325-Deluxe-Ratchet-Tubing-Bender-Reverse-Bender-60342-Included/101638219?gpid=41279011981&gpkwd=&goog_pla=1&gclid=CIaCz5KKjLUCFStgMgodW3gAYg

see if you can rent or borrow one of these as they are a little pricey.
if something else works for you, then great.
 

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Discussion Starter #4
well id agree but guess what size hose is coming out of a 405 lph fuel pump its small even fore and other company use small hose if the pump isant any bigger i see know advantage

On a side not a single 405 on e85 on 10 psi on a 35 shot with a 11.2 air fuel ratio, not counting meth the pump had no issues on another note just at fore innovations has customers on gas making over 600 rwhp on gas on a boosted application with just one pump and stock lines and everthing

robert
The advantage will be that a bigger tube, properly bent, will help reduce losses. That is my theory that I'm gonna actually test out---I have another fuel hat here, it will remain stock so as to compare the two.

GM, I would seriously consider using one of these as a tubing bender.
I tried using what you have pictured above for 1/2" aluminum line, and all it would do is kink it.
I tried using a bender with a lever....still kinked.
Here is what works perfect with no kinks.
http://www.bonanza.com/listings/Yellow-Jacket-60325-Deluxe-Ratchet-Tubing-Bender-Reverse-Bender-60342-Included/101638219?gpid=41279011981&gpkwd=&goog_pla=1&gclid=CIaCz5KKjLUCFStgMgodW3gAYg

see if you can rent or borrow one of these as they are a little pricey.
if something else works for you, then great.
I totally agree that one of those tubing benders likely sucks. Which is why I ordered two, and will both be introduced to both my plasma cutter, my tig welder, and thick mild steel.

Can you see what I plan to do now? :D
 

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The advantage will be that a bigger tube, properly bent, will help reduce losses. That is my theory that I'm gonna actually test out---I have another fuel hat here, it will remain stock so as to compare the two.

...

Can you see what I plan to do now? :D
What losses are you referring to?

I'm pretty sure that with the gained VOLUME you'll lose PRESSURE with that larger dia. line...

Have you crunched the numbers on that?
 

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I'll give ya a hint the forumla's named after this guy called Boyle. :D
 

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Discussion Starter #7
What losses are you referring to?

I'm pretty sure that with the gained VOLUME you'll lose PRESSURE with that larger dia. line...

Have you crunched the numbers on that?
Im talking about losses in flow due to bends and kinks in the stock tubes.

As for larger diameter, the same could be said about using-8AN fuel hose, but that's not my point. My point is that I believe that there are some localized losses due to the stock tubing being the way it is.

I'll give ya a hint the forumla's named after this guy called Boyle. :D
Actually, his name was Bernoulli. You're thinking about gas flow instead of liquid. ;)

Besides, I'm counting on the pressure dropping. Yes, because in the case of bends and kinks, the pressure that builds up is not due to fluid flow, but resistance. I want the pressure to drop in the sense that I want the restrictions that [could] be causing the pressure rises because then it could allow more fluid flow before reaching the fuel system pressure.

That would be like saying "oh I'm gonna put in really really small tubing and a super small pump to save on costs because this gets the psi up to 40 in the fuel a lot easier!" yea the pressure will get up there, but you have crap for actual flow.
 

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LOL... I understand your take on flow losses due to resistance in the stock tubes. I was ribbing you about loss of fuel pressure due to the larger diameter of the lines. I'm sure the difference is ultimately negligible in terms of what any fuel pump worth a crap can pump. However, my point is, the pump(s) WILL have to work harder to maintain the same pressure in those lines as it/they would have to work to maintain pressure in the stock lines.

We are talking about gas flow. ;) A GAS (GASoline) which is both a gas (vapor) and a solid (fluid) so both law's/principals apply. And GASoline has a very high tendency to vaporize. For those materials that can exist as a vapor, some vapor is present even when the material is in its liquid or solid state.

Touché.
 

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Yup I agree with you. They will have to work harder, but it will not be for naught since there should be extra flow in there.

As far as gasoline vaporizing, would it still do that under 40+ psi of pressure? I would tend to think it would be subdued at that point, otherwise the fluid flow modeling of fuel injectors would be highly unstable since fuel flow would be all over the place :zdunno:
 

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Ohh... about 275%?
actually just a bit more than that. The tube was cut with one of those roller cutters, so it has an edge to it on the inside. Remember, 1/2" OD, 0.035" wall. ;)
 

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Yup I agree with you. They will have to work harder, but it will not be for naught since there should be extra flow in there.

As far as gasoline vaporizing, would it still do that under 40+ psi of pressure? I would tend to think it would be subdued at that point, otherwise the fluid flow modeling of fuel injectors would be highly unstable since fuel flow would be all over the place :zdunno:
Highly unlikely, the "boiling point" of any liquid is more of a factor of the pressure / temperature relationship. On carbed vehicles this was called Vapor lock .. the engine heat would cause the fuel to boil inside of the lines, but of course these were around 6 psi on average. With a Return style system, the fuel is heated and returned to the tank making the overall fuel temperature higher than it would be in a Returnless system. Back in the 80's, Ford dealerships were marketing a device to make it seem like your gas mileage was increasing which basically routed the fuel lines through the radiator hoses, causing the fuel to expand which made the fuel level read higher in the tank and on the gauge .. :tongue:
 

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actually just a bit more than that. The tube was cut with one of those roller cutters, so it has an edge to it on the inside. Remember, 1/2" OD, 0.035" wall. ;)
305% then.

Bonus points for being the only one daring enough to attempt this venture? lol
 

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305% then.

Bonus points for being the only one daring enough to attempt this venture? lol
Yea bonus points = I didn't charge you normal shop rate of $60/hr for your crank gears :tongue:
 

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Well that's a bargain then, it would have cost me a month's pay otherwise! :tongue:
 

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Hmmm

I don't have such problems. If I get to where I need more fuel I just add a larger pump & supporting injectors LMAO!!!


1/2" line to the front and 3/8" return and enough pump to keep volume and pressure.
 

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Cool project!

Some observations:

The overall flow is set by the pump pressure, and the smallest orifice it flows thru.

If there is no orifice, then it's a flow calculation based on the curves in the line.

Adding cross section to the system will increase peak flow.

Pressure drops are curves and restrictions, if everything's the same size, pretty much. But It's never the same all the way thru. :)



Something I haven't seen any mention is the fuel mass; increasing volume of the piping increases the mass of the fuel in the line.

This fuel is hard to start (and stop); it wants to stand still while the car moves out from under it, at launch...

Straight fuel line runs increase the inertial effect of the acceleration on the fuel pressure.

A 10' column of fuel 0.1320215375"sq is about a half-pound of fuel. (.410"dia)

A large diameter hard bend at the rear of the car can help, but it still opposes flow.
(think of the mass of the column of fuel, as you come off the line; the acceleration is trying to stuff the fuel back in the pump.)

If you're this serious about it, you should flow model the whole line, Including inertial effects, at your maximum expected acceleration.

At least with a return type system, you don't have to worry about what gear shifts are doing to your injectors and regulators. :) (think about the transients...)

I've looked at it a bit; it looks like with 40lb injectors, you might want to look at the reflected pressure pulse at the fuel regulator after the injector closes, there could be a resonance with the regulator diaphragm, which could cause the fuel pressure to drop, when you want it open. As changing the pressure setting changes the spring pressure, the resonance will shift depending on the regulator setting.

Just my $0.02; YMMSV. :)
 
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