Fuel pump specs (carbureted) , updated. Keep them specs comming!. Its all just aviable information bundled on one page.
Not going to discus whats my favourite, its just info to share and make your own plan.
Webers work best at approx 4 psi of fuel pressure (Not 2 psi like many of the older books stated.)
Holleys run 6-7 psi fuel pressure.
and you need Volume not Pressure to keep the float bowl full of any carburetor.
Fuel pump specifications:
Facet silver Top, 36 GPH free flow, 23 GPH @ 2 psi. 11.5 GPH @ 4 psi.
Facet Red Top 40 GPH free flow, 35 GPH @ 2 psi. 20 GPH @ 4 psi
Facet Blue Top, 45 GPH, 38 GPH @ 2 psi. 23 GPH @ 4 psi
Facet Dura Lift 40285, 33 GPH Free Flow, 4-7 psi @ no flow.
Facet Dura Lift 40222, 33 GPH Free Flow, 9-11 psi @ no flow, 17 GPH @ 4 psi
Facet Dura Lift 40290, 50 GPH Free Flow, 12-15 psi @ no flow, 20 GPH @ 8 psi
Holley Red flows 97 Us GPH free flow - 67 Us GPH @ 5psi, 71 GPH @ 4 psi
Mallory Comp 110, 110 free flow, about 90 Us GPH @ 6psi. about 95+ Us GPH at 4psi, factory preset at 7psi @ 20 Us GPH.
Mallory Comp 140, 140 free flow, 120+ Us GPH @ 6psi. about 135 Us GPH @ 4psi, factory preset at 12 psi @ 110 Us GPH
Carter P4600HP flows 100 Us Gph free flow.
Steward Warner 240A, ?
The more pressure a pump has to deliver the less GPH is pumped by the pump. That’s why we are not interested in free flow numbers given by the manufacturers.
Modern fuel pump calculators calculate:
250 bhp you´ll need 24 GPH @ 4 - 7 psi, that’s about max a Facet Dura Lift (40290) can handle.
350 bhp you’ll need 33 GPH @ 4 - 7 psi, so that leaves a Facet Red & Blue Top out.
400 bhp you’ll need 37 GPH @ 4 – 7 psi.
4 psi for the weber carb, 7 psi for a Holley carb.
Facet Red & Blue top pumps have no flow at 7 psi while Holley recommends 7 psi at idle, and a minimum 4 psi at engine redline for their carbs. So that rules a Facet pump out when running a Holley carburetor on any engine.
You also don’t want to be on the edge of a pumps capacity cause as the pump wears it affects its GPH.
Especially the Facet Red & Blue wears out fast. Unless you don’t drive that often.
If you run multiple carbs, you’ll have to take into account multiple float chambers have to be filled at the same time and rate. And as multiple carbs have multiple pump jets you’ll need some extra capacity (Volume in GPH) to keep up the demand.
Facet Red or Blue pumps can be used if running them simultaneously.
Red & blue are the same pumps with the difference that the Red has a filter inside and the Blue not (no restriction hence the slightly more GPH).
Not going to discus whats my favourite, its just info to share and make your own plan.
Webers work best at approx 4 psi of fuel pressure (Not 2 psi like many of the older books stated.)
Holleys run 6-7 psi fuel pressure.
and you need Volume not Pressure to keep the float bowl full of any carburetor.
Fuel pump specifications:
Facet silver Top, 36 GPH free flow, 23 GPH @ 2 psi. 11.5 GPH @ 4 psi.
Facet Red Top 40 GPH free flow, 35 GPH @ 2 psi. 20 GPH @ 4 psi
Facet Blue Top, 45 GPH, 38 GPH @ 2 psi. 23 GPH @ 4 psi
Facet Dura Lift 40285, 33 GPH Free Flow, 4-7 psi @ no flow.
Facet Dura Lift 40222, 33 GPH Free Flow, 9-11 psi @ no flow, 17 GPH @ 4 psi
Facet Dura Lift 40290, 50 GPH Free Flow, 12-15 psi @ no flow, 20 GPH @ 8 psi
Holley Red flows 97 Us GPH free flow - 67 Us GPH @ 5psi, 71 GPH @ 4 psi
Mallory Comp 110, 110 free flow, about 90 Us GPH @ 6psi. about 95+ Us GPH at 4psi, factory preset at 7psi @ 20 Us GPH.
Mallory Comp 140, 140 free flow, 120+ Us GPH @ 6psi. about 135 Us GPH @ 4psi, factory preset at 12 psi @ 110 Us GPH
Carter P4600HP flows 100 Us Gph free flow.
Steward Warner 240A, ?
The more pressure a pump has to deliver the less GPH is pumped by the pump. That’s why we are not interested in free flow numbers given by the manufacturers.
Modern fuel pump calculators calculate:
250 bhp you´ll need 24 GPH @ 4 - 7 psi, that’s about max a Facet Dura Lift (40290) can handle.
350 bhp you’ll need 33 GPH @ 4 - 7 psi, so that leaves a Facet Red & Blue Top out.
400 bhp you’ll need 37 GPH @ 4 – 7 psi.
4 psi for the weber carb, 7 psi for a Holley carb.
Facet Red & Blue top pumps have no flow at 7 psi while Holley recommends 7 psi at idle, and a minimum 4 psi at engine redline for their carbs. So that rules a Facet pump out when running a Holley carburetor on any engine.
You also don’t want to be on the edge of a pumps capacity cause as the pump wears it affects its GPH.
Especially the Facet Red & Blue wears out fast. Unless you don’t drive that often.
If you run multiple carbs, you’ll have to take into account multiple float chambers have to be filled at the same time and rate. And as multiple carbs have multiple pump jets you’ll need some extra capacity (Volume in GPH) to keep up the demand.
Facet Red or Blue pumps can be used if running them simultaneously.
Red & blue are the same pumps with the difference that the Red has a filter inside and the Blue not (no restriction hence the slightly more GPH).
