low pressure inline fuel pump with 1/2" inlet/outlet that will flow thru if it fails?

[mtomac]

the 6.5 pump is the closest thing I've found but it has 3/8 inlet/outlet, anyone found anything else?

[ 07-25-2003, 10:23 PM: Message edited by: Micheal Tomac ]

[EWC]

Have you considered any of the high performance fuel pumps , like a Barry Grant ? The BG 400 has a bypass regulator that is built in and adjustable . I ran one on a drag car and really liked it , but I could only get the pressure down to 9 psi at the lowest .

[Kennedy]

Contrary to popular belief, we do not need a high psi, high volume lift pump. Just a switch from vacuum to PSI is all we are looking for...

I haven't gotten to the electronics part yet, but have some prototype pump/fitting combos just about ready to go.

[a64pilot]

John,
I would think that high volume, low pressure would be ideal. Something along the lines of a centrifical (sp?) would be nice if any such thing exists.

[mtomac]

Edelbrock sells a pump made by Essex Industries part #1792 that has a free flow rate of 160 GPH, and is factory preset to 12 PSI with 1/2" NPT inlet/outlet. A regulator or a parallel bypass would get the psi down to where we need it. The newer 6.5 pump is 10-15 psi but only flow 32 GPH with a 3/8" inlet/outlet

[Kennedy]

The actual volume is quite low as evidenced by the ability of the little 6.5 pump to keep up...

The psi on the 6.5 pump is over rated OR it just never gets there. One or the other, but 5-6 psi is the norm. So long as we stay on the positive side of atmosphere a lift pump should be beneficial in keeping gasses entrained. Beyond that, I believe there will be little/no gain...

[a bear]

Why high volume? The 6.5 lift puts out way more than whats needed. If any pump puts out less than whats needed it would not be able to remove the vacumn due to getting out run by the Bosch LP suction pump. Bottom line is if it creates pressure it's enough.
I would think a high volume pump would have to bypass a lot to get the pressure down due to the high volumn design itself. Would take a hell of a bypass. Any volume that is not needed would be recirculated. Then there goes the need for high volume. :D

[ 07-28-2003, 07:32 PM: Message edited by: a bear ]

[NWDmax]

Just ran my lift pump down to 1/2 psi @ idle and it runs as good as ever with none of the dreaded
a** present.
I think the stock pump can pull more than we'd believe.... ;)

[NWDmax]

With the volume of fuel being bypassed wouldn't that heat the fuel even more and possibly cause an "outgassing" condition adding yet more bubbly to the fuel?

[a64pilot]

a bear,
High volume would be nice as no matter what mods you did in the future, fuel starvation is not an issue. I think it is an issue for some of these really strong Cummins as an example. With a centrifical pump there would be no bypass, the pump cannot by design produce a high pressure, the compressor would simply "slip", shouldn't be cavitation unless spun at a high RPM. Also a centifical pump would allow fuel to flow through if the pump motor failed. Now I don't know if such a fuel pump exists except for turbine engines, just wondering.

[Gbenzx01]

Mike,
We installed the Stanadyne fm100 pump/filter/water sep @ 84gph & 8psi but still have 3/8 ports unless the fm1000 is used.
No pic but we installed at frame rail almost identical to CntrlCalDmax. It is 5mic just until it gets swapped @ abt 5000mi since we too have the cat 2mic post oem.
Did not install pressure guage but used one at cat shop that screwed into bleed port on cat filter. With everything direct & no fuel bypassed it showed abt 5.5psi @ idle setting. Punchin the hi idle upto 1250rpm it dropped to abt 5 psi & very little difference @ 1800rpm. After setting the bypass valve on the frame rail @ a 45 degree angle all rpm checks show an avg of 5psi loss.
We're running at the 45 deg setting & at hwy speed tripping the pump switch makes no difference when running w/o trailer. With one of the 5ers(8k & 10k) can definitely see a loss of power until pump is back on & valve is returned to 100%. Will try the heavy weight gnecks when I get the hookup & see how much it bogs down pulling 14 & 15klbs. Still need the guage if I can get a chance sense the static chks mean very little with a truck made to work like this one.
If, if I were to guess, do believe that under very heavy load the fm100 needs to be at 100% & no bypassing to keep the system out of suction mode. For us, the most ideal configuration.....

Thanx, Gben