Does anyone know what the stock intank fuel pumps are rated for IE 190lph?

 

The pump on the 96 is rated at 95 LPH vs. 58 PSI when used on the 300 and 105 LPH vs. 39 PSI on the 302 and 351. As long as you have the high pressure pump(s) in the tank(s), yours should be similar.

FWIW at a BSFC of 0.5 lbs/HP-hr, 105 LPH provides enough fuel for about 310 flywheel HP allowing for about 10% excess capacity.

 

Do you think the 1st generation Lightnings with the dual tanks had the same output intank fuel pumps?
Or were they high ouput for the Lightnings?

 

Not a clue.
IIRC they were only rated at something like 240 HP. If that is correct, there would be no reason to use a different pump.

 

The 1995 F-series fuel pumps (F4TU-9350-A1A) are rated at 125 LPH @ 310 KPA.

 

310 kPa converts to 45 PSI

 

The reason I'm asking guys....is because I'm looking into a kit the Lightning guys use. It's called a 2 pump trick. It works off a Hobbs switch that activates under boost and energizes the 2nd tank. So I would have both pumps pushing fuel at the same time.
It's a pretty wild setup.....and I need all the fuel I can get for my 408w and 6psi blower.

 

It would depend on the size of your injectors and the fuel pressure you are running.

If you have stock injectors and fuel pressure regulator then one pump is all you need.

The in-tank 1990+ pumps put out about 100 PSI against a blocked head.
They are rated at 125 LPH (33 GPH) @ 310 KPA (45 PSI) so the stock pumps can put out more than enough fuel for the 460.

A 460, 351 & 302 have a top fuel pressure of 45 PSI (310 KPA) and a 300 engine 60 PSI (415 KPA) so there is no problem. If you want more than you would have to go with an adjustable fuel pressure regulator.

The Injectors Flow #/HR are for the 300 = 14#/HR, 302 & 351 = 19#HR and the 460 at 24#HR.

So the injectors @42 PSI for the 14#HR = 2.45 GPH, 19#HR = 3.3 GPH & 24#HR = 4.2 GPH.

So a 460 at WOT = 33.6 GPH @ 42 PSI. and that would be enough fuel with a 33 GPH @ 45 PSI as the pump would put out more GPH at 42 PSI.

Any engine under the 460 would have more than enough fuel.

 

I'm sorry I forgot to give u a run down off my setup.

408w roller engine,
Powerdyne 9 psi s/c w/ a FMU 4:1 disc
FMS Massair conversion kit,
42# injectors,
PMAS 95mm MAF
Kirbarn Adj fuel pressure reg.
Full MSD ignition w/ boost retard (BTM)
Edelbrock Performer ported upper and lower truck intake
Heddman full length headers w/ custom exhaust


I'm looking into this 2 pump trick because I installed a AEM wideband A/F guage and I'm running alittle lean a W.O.T
It's reading 12-13 and I know I should be in the 11.5 area.

 

Sounds like you would need two pumps. As far as I know all injectors are rated at 43 PSI, so a 42# injector at about 42 PSI (WOT) would need more fuel then one pump could put out.

 

I also installed an inline Walbro 255LPH pump on the frame rail that is activated by a pressure switch.
So hopefully all 3 pummps will get me what I need.
What do you think?

 

I would think it should.

 

Thanks for all the advice.
I'll keep u posted after install.

 

Two things to consider in your sizing:
1) Boosted engines are a bit less efficient in their use of fuel. Use a BSFC of 0.55 lbs/HP-hr.
2) In order to maintain the same pressure drop across the injectors, your Fuel Metering Unit is going to raise the backpressure against which the pump(s) must flow. Typically gerotor pumps with low viscosity fluids like gasoline lose a fair amount of flow as pressure increases. IIRC there are flow/pressure curves for all the various Walbro pumps on the net. Time for a search.

 

The original pumps in my 1994 F150 5.0 were 77lt per hour I switched to 190 lt.


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