Upgrade fuel pickup or not ?
#1 _parsons5000_
Posted 18 July 2014 - 09:12 PM
#2 _Bomber Watson_
Posted 18 July 2014 - 09:31 PM
You probly dont, but i would.
Cheers.
#3 _parsons5000_
Posted 18 July 2014 - 09:45 PM
#4 _Bomber Watson_
Posted 18 July 2014 - 09:56 PM
Not that hard really, cut the 5/16" line off the sender unit and braise some 3/8" stuff on, suitably bent.
Cheers.
#5 _parsons5000_
Posted 18 July 2014 - 10:05 PM
#6 _Bomber Watson_
Posted 18 July 2014 - 10:29 PM
Yep.
Reasonably straightforward if you have basic metal working skills, if not, any local shop should be able to do it easilly.
Cheers.
#7
Posted 18 July 2014 - 11:44 PM
The suction side of a pump is the weakest so it usually has a larger diameter hose than the pressure side.
I doubt you would get any benefit from the 3/8" fuel line if the pump is sucking through a 5/16" pickup. The Brown Davis tanks have an optional 1/2" pickup.
Have a look at the Aeromotive fuel system diagrams.
http://aeromotiveinc...etedsystems.pdf
#8 _hutch_
Posted 19 July 2014 - 09:04 AM
Isn't it like having a 200 mm water main running past your home and you have a 20 mm tapping coming off,you only get what the 20 mm pipe will flow ??? Or am I missing something here
#9 _parsons5000_
Posted 19 July 2014 - 11:39 AM
#10
Posted 19 July 2014 - 11:44 AM
Yes the maximum flow rate in any system is determined by the component in the fuel system with the lowest flow rate. If the engine does not require more fuel than the amount of fuel that can be delivered by a 5/16 fuel line then you are wasting your time going bigger.
The amount of fuel that flow through a fuel line is dictated by the size of the line and the fuel pressure or vacuum.
The mechanical factory pump is able to generate considerably more vacuum on the pickup side than the typical delivery pressure. If both the pickup and delivery fuel line are the same size then at a delivery rate of 6 psi the delivery fuel line will usually be the restriction.
A typical electric pump is able to generate more pressure on the delivery side than it is able to generate vacuum on the pickup side. If both the pickup and delivery side are the same size then at a delivery rate of 6 psi the pickup side will usually be the restriction.
Edited by ls2lxhatch, 19 July 2014 - 11:45 AM.
#11 _parsons5000_
Posted 19 July 2014 - 12:43 PM
i just dont want any restrictions so what would u suggest with my 400 hp setup ? i was going to run a holley inline 70 gph type and run a reg on the carcby log setup with a 3/8 line the whole way
?
#12
Posted 19 July 2014 - 03:03 PM
The best way to check your fuel system is to plumb it up out of the car and measure the fuel flow produced at your delivery pressure. Make sure the pump height to fuel height is the same as it will be in the car.
3/8" hose is the equivalent of -6 hose. It has an ID of 3/8"
3/8" tube is the equivalent of -6 tube. It has an OD of 3/8" the ID is determined by the wall thickness of the tube. It will always be less than the hose ID.
You can get a guide to hose sizes by looking at the sizes used by fuel system manufacturers.
http://aeromotiveinc...etedsystems.pdf
Or you can can use the the Ryco Chart.
The red line shows the hose size required for a low suction line to deliver 1 US Gal / min (60 US GPH)
It is drawn from a flow rate of 1 Gal/Min (60 GPH) to a flow velocity of 2 ft/sec (low suction line). It crosses below -8.
The blue line shows the flow rate produced by a -6 line at low suction.
The blue line is drawn from a flow velocity of 2 ft/sec through -6. It crosses at a flow rate of around 0.7 US Gal / min ( 42 US GPH)
The yellow line shows the flow rate required to delivery 1 Us Gal / min using -6.
The yellow line is drawn from 1 US Gal / min through -6. It crosses with a low flow rate of around 3.75 ft/sec.
Edited by ls2lxhatch, 19 July 2014 - 03:04 PM.
#13 _hutch_
Posted 19 July 2014 - 04:02 PM
#14 _Bomber Watson_
Posted 19 July 2014 - 04:06 PM
How much fuel the car uses in general driving, or even on a race track, and contiuous WOT are two very different things Hutch.
#15
Posted 19 July 2014 - 04:13 PM
also allow for Ethanol Fuels (316 S/S tube lines) etc, like Corrosion and Double the Flow.
never gave the pick-up a thought, till you made this thread Ryan
#16
Posted 19 July 2014 - 05:14 PM
400 hp naturally aspirated with take around 27-34 US GPH. If using nitrous then 34-41 US GPH.
See this document.
Aeromotive Techinical Bulliten #501
Edited by ls2lxhatch, 19 July 2014 - 05:22 PM.
#17 _Bomber Watson_
Posted 19 July 2014 - 05:34 PM
Which, funnily enough, is roughly a tank of fuel in 20 minutes
When planning a fuel system you need to plan it for WOT fuel requirements, not your average fuel usage.
Cheers.
#18 _hutch_
Posted 19 July 2014 - 07:07 PM
#19 _Bomber Watson_
Posted 19 July 2014 - 07:16 PM
Depends on what your doing mate?
Probably never, but for $20 worth of line and a few hours tinkering is it worth risking leaning out a 10k + engine?
Cheers.
Edited by Bomber Watson, 19 July 2014 - 07:18 PM.
#20 _parsons5000_
Posted 19 July 2014 - 09:15 PM
#21
Posted 20 July 2014 - 12:07 AM
The only way to know for sure is to test the fuel system in your car.
Disconnect the fuel line from the carby and run it into a 20 lt fuel container for one minute then measure the amount of fuel in the container.
#22
Posted 20 July 2014 - 12:11 AM
good measure ^
#23 _Mint_
Posted 20 July 2014 - 06:54 PM
for the first time recently i watched the fuel pressure gauge on my 308 on the dyno...at idle and cruise(bout 3000rpm) it had 7 psi then at wot it flickered and dropped straight down to 3 psi
i have a bigger pick up line in the sender unit on mine 3/8" steel tube did it myself years ago
1/2" ally tube all the way to the bay ..then -6 braid down the pump and then to the carb
it has a holden hi pressure mech pump
i am now in the process of putting an electric put on the car
Edited by Mint Julip, 20 July 2014 - 06:55 PM.
#24
Posted 25 July 2014 - 04:02 PM
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