how big a fuel pump do you need?


Staff member
for a decent performance engine, that many guys build, I think your generally going to find an engine used on the street having under 450 rear wheel horse power equipped, with a carburetor(S) you'll need consistent fuel flow at 5-6 psi,and 80-110gph ,Holley,G.M. PERFORMANCE, SUMMIT RACING, edelbrock makes a decent manual fuel pump that produces a rated 80- 110 gph suitable for most street cars, there are several electrical in line fuel pumps available
but once you exceed about 450hp, ID strongly suggest a AN8-1/2" fuel line and a 3/8" return line with a high quality fuel pressure regulator be used

calculating the engines potential fuel requirements at a given horse power level is hardly a "BLACK MAGIC ART FORM", all you need is to use simple math
before you buy any electric fuel pump be sure it pushes the required volume per minute and at the correct pressure level,
read the related info carefully, efi pumps will require a fuel pressure regulator and generally run in the 44 psi-70 psi ranges
low pressure electrical fuel pumps are available for carb applications
Id just point out that in most O.E.M, in the fuel tank electric fuel pumps are cooled by sloshing fuel, if you let the tank regularly get below about 1/4 full the pump spends more time not being cooled to ideal levels and statistically it tends to wear out a bit faster, Id also point out that adding several ounces of Marvel Mystery Oil to each fill-up seems to help reduce wear issues and varnish and rust problems inside the fuel tank

look at the pictures in this thread carefully, similar too this,
the electric fuel pump is located in the lower 1/4 of the tank too insure its cooled by sloshing fuel



Filtering the Facts: How to Avoid Major Fuel Filter Mistakes


There are lots of options when it comes to fuel filters, but there are only a few smart choices for any engine making over 500 hp. Regarding filers, bigger is always better.

Photos and Words by Jeff Smith

In Shakespeare’s Richard III, in the middle of the battle, he cries “A horse, a horse! My kingdom for a horse!”

The 21st Century equivalent of that cry is a bit more muddled because when horsepower dies today, it might be more difficult to figure out where it went! We recently visited a shop where they had just removed a thumpin’ 572c.i. Chevrolet Performance big-block from a customer’s car because he had given up trying to make the engine run right. The solution was to swap in a late model LS engine.

Part of the conversion called for an upgrade from the original carbureted fuel delivery system to one designed for high-pressure and EFI. While removing the original fuel line, the guys discovered the real reason why the 620 hp Rat motor never ran right. The rear-mounted electric fuel pump was more than big enough to feed the engine, but was plumbed using a fuel filter with an area the size of a quarter. The filter was plugged with all kinds of debris and was obviously incapable of flowing anywhere near the amount of fuel the engine required. The engine didn’t burn a piston because the filter restricted flow so severely, it couldn’t make enough power to hurt itself!

This may sound like a simple oversight — which it obviously is. But, this is not an isolated case. Making big power in the 21st Century has never been easier. Magazine stories today don’t consider a 500-hp engine to be anything special. Attention seems to have focused now on street engines making upwards of 1,000 hp. What is often overlooked is the volume of fuel it requires to make this kind of horsepower. Yet, it seems many enthusiasts have not made the mental transition when it comes to filters. While most everyone’s attention is focused on high capacity fuel pumps, there’s more than a little thought and consideration that must be paid to the filter as well.

Let’s start with the more demanding EFI fuel delivery system. The best way to build a high-pressure EFI fuel delivery system is by designing it as a return system. This starts with a pre-filter ahead of the pump, along with another filter after the pump with a finer filter and the entire system plumbed with sufficient size lines and full-flow fittings. The return line must also be the same size as the feed line to prevent backpressure. We will focus this story on filters, but an emphasis on the entire system as a whole is the only way to create a successful and efficient fuel delivery structure.

The most critical location or position in any fuel delivery system is the inlet side of the pump. All pumps, including electric fuel pumps, will deliver maximum performance when the inlet to the pump is unrestricted. This is because pumps are designed to push fuel and are generally not efficient at pulling fuel into the inlet. This is why submerged, in-tank pumps are by far the most efficient. However, an inlet filter is still required because high pressure EFI pumps operate using very tight tolerances. If debris finds its way into the pump, the result is likely a quick failure.

We will be using Aeromotive’s recommendations for filters, and these same requirements will hold true with any high-output fuel delivery system. The idea is to create a balance between protecting the pump while minimizing flow restrictions. Aeromotive specifies a 100-micron filter for the inlet side of an EFI pump. A micron is equal to 0.00039-inch, which means a 100 micron filter is capable of trapping debris that’s at least 0.039-inch in diameter and perhaps slightly smaller. This will prevent large foreign material from harming the pump. As the filter’s micron rating number becomes smaller (trapping finer particles) it also becomes more of a restriction. A 100 micron rating on the inlet side still filters large particles but is a minimal restriction. On the high pressure side of the pump, the spec is far tighter to remove material that could foul a fuel injector. The Aeromotive spec for this filter recommends 10 microns (0.0039-inch), a full 10 times finer than the inlet side.

But, even more important than the particle size is the filter’s surface area. Common sense dictates that a large surface area for a filter is probably more important than its screen size. A large surface area allows the filter to do its job for an extended period of time without worry that debris will reduce fuel flow. That’s why these filters are so large. Keep in mind that during part-throttle operation, nearly all of the fuel is returned to the tank. This moves the fuel through these filters far more often than a non-return system.

There’s also a choice of filter materials. Aeromotive and others offer both paper (cellulose) or a cleanable stainless steel. Obviously, the stainless media allows the user to clean the filter and re-use it — assuming, of course, your cleaning solution (like dirty solvent) does not add debris to the filter!

One important point is to never use a cellulose or paper filter with E85 fuel. Aeromotive says they have seen issues where ethanol creates a gel when used with a paper fuel filter. Remember, ethanol is predominantly an organically-based fuel, as opposed to pure gasoline that is petroleum-based. E85 is no different that grain alcohol except for the 15-percent gasoline mixed with it. So, to prevent this “biological fouling” — essentially a bacterial slime — from growing inside your fuel system, stick with stainless steel filters. To support this, Aeromotive makes a special 40-micron stainless steel filter specially designed for use with E85.

Carbureted systems are no less vulnerable, as evidenced by the builder’s misuse of that tiny fuel filter on that 572c.i. big-block example in our story introduction. It’s easy to understand how this oversight could happen. While carbureted fuel pressures are significantly lower than EFI systems, fuel volume is still a crucial requirement. The engine’s horsepower potential determines the flow capacity required of the system. You can’t make horsepower without fuel.

A simple equation can help in determining capacity. We’ll keep the math to a minimum, but if a normally-aspirated big-block Chevy is capable of 750 hp, let’s assume a BSFC number of 0.5. BSFC is the acronym for brake specific fuel consumption — a fractional rating of the pounds of fuel required to make one horsepower for one hour. In this case, that comes to a half-pound of fuel per horsepower per hour. If the number were larger (0.65 for example), the engine would require more fuel to make the same horsepower. Conversely, if the BSFC number is smaller (0.35 as an example), it is more efficient at converting fuel into power, requiring less fuel.

So with a BSFC of 0.5, this means for a 750-hp engine, we divide 750 by 0.50, which gives us a minimum of 375 pounds of fuel per hour. In order to ensure we will supply enough fuel, we will add a little “head room” to the number, making it 400 pounds of fuel per hour as a safety margin. Divide 400 pounds by the weight of gasoline at 6.2 pounds per gallon and that equals almost 65 gallons of fuel per hour at a minimum pressure of at least 5 to 6 psi.

Despite the fact carburetors don’t demand the same pressure as EFI systems, flow is still important. With flow rates increasing with higher horsepower engines, a full return-style system is the best way to build a system, even for a carburetor. This can be easily accomplished with a return-style regulator.

If you’re not sure of the cartridge’s filter rating, it is stamped on the closed end of the filter. In this case, it’s a 100 micron filter.

Regarding filters for a carbureted application, a 100-micron inlet filter is still a good idea while the pressure side filter does not have to be quite so fine, so a 40 micron filter with a large surface area would be the best. Because of these lower pressures, these inline filters can be slightly smaller with no fear of flow restrictions. For example, the Aeromotive PN 12335 filter offers a slightly shorter 5.5-inch long body with a stainless steel 40-micron filtering ability that can easily accommodate even a dual-carbureted Pro Stock big-block application.

As street cars become more sophisticated and engines continue to make more power, the fuel filter is one of those few instances where bigger is better and where more surface area only means more flow. So at least here, you can’t go wrong by going big.

Sources: Aeromotive; 913/647-7300;; Holley Performance Products; 270/781-9741;; Edelbrock(Russell); 310/781-2222;
how can you possibly set up your fuel system unless you know the pressure and flow rates required and what currently exist's



(HP x BSFC = pounds of gasoline)
500 hp x .5 BSFC = 250 pounds of gasoline.
500 hp x .75 BSFC = 375 pounds of gasoline.

Since a gallon of fuel weighs about 6.2 pounds, we find that in our first example, 250 / 6.2 = 40 gph (gallons per hour) and 375 / 6.2 = 60 gph.

the needle/seat, in a carbs float bowl,controls the fuel level by opening and closing the needle valve, in the fuel bowl, and its designed to generally can control fuel inlet pressures below 8 psi
(but generally works best at 5-6 psi)volume of flow only come into play once the needle valve opens and that relates to how quickly the floats being raised back to the point the needle seat closes

A carburetor setup requires very low fuel pressure—somewhere between 5 and 6 psi,pressures higher than 6 psi can force open the flow control valve on some carbs,
be aware that you,ll need to correctly set the carbs floats to regulate the fuel level in most carbs and the needle & seat valve that controls fuel flow into the carb can get crud trapped between the needle and seat causing the fuel bowl to constantly flood, so check that carefully, if thats your issue!



A COUPLE HIGHER FLOW ELECTRIC FUEL PUMPS (this pump has proven to work really well in many 500hp-to-600hp carb equipped cars) (this is overkill unless your exceeding 600hp) makes no logical sense to run 1/2" or AN#8 lines to and from a pressure regulator , or fuel pump or fuel filter,with restrictive AN#6 or 3/8" lines so use a regulator and lines and fittings that all match and allow max flow with little restriction

if your looking for an EFI fuel pump this link and its sub links will be useful


your limiting the potential power its designed too feed to under 400hp
fuel injection usually requires a 40psi plus fuel pressure, the line size and the fuel pressure regulator will have a big effect on your results, theres some threads and calculators above that will help,
generally a 110-150 gph pump and 3/8" / AN#6 lines minimum ,works fine up to about 550- maybe even 575hp, IN A FEW CASES with carbs BUT above that POWER LEVEL Id suggest a 1/2 AN#8 line
(Ive always used AN#8 and a 135 gph-150 GPH rated pump on carb equipped application's for street/strip cars")
and selecting a fuel pump that can supply at least 50% more flow than the carb or injectors can flow to compensate for the flow restrictions the filter and lines etc. provide. THERES A SET OF CALCULATIONS BELOW TO ALLOW YOU TO MATCH YOUR APPLICATION TO WHAT YOU NEED IN A FUEL PUMP FLOW RATE
now I,m sure youll find formulas that indicate you can easily get by with a 70-80 gph fuel pump on most street driven engine combos, but my experience, and that of many other muscle car owners, has shown that the rated flow and the actual fuel delivery varies due to restrictions in fuel lines and fittings on those fuel lines and inertial loads, during acceleration
I generally run hard lines for fuel supply and return, but I have run flex lines inside 3/4" emt electrical tubing inside the frame rails ,except for the last 18" between fuel pressure regulator and carb. I buy flex and or hard lines at the local hydraulic supply after I measure very carefully then have them fabricate the lines.. with the correct ends fabricated on the ends of the lines.
Ive found , running 3/4" EMT tubing which is fairly easy to bend then slipping flex line thru it to be a good system, and yes before you ask youll want to have two because youll have a RETURN LINE , but having two hard lines and skipping the flex inside the protective outer EMT, takes up less room
FuelFlowDiagram02a1.jpg ... a-5250.pdf

one of the most common mistakes less than experienced performance enthusiasts, face and very commonly over-look, is the fact that the internal cross sectional area on many hydraulic and fuel line fittings are considerably more restrictive to flow that the fuel limes or hydraulic lines inside diameter they were designed to be used with, and it varies a great deal between different manufacturers, now ideally the fittings internal passage cross sectional area is both consistent and the same or greater that the tube or hydraulic line size, it listed to match, , so a 1/2" inside diameter fuel line, or hydraulic lines?hoses, for example should have components for the connections and fittings that have significantly smaller internal cross sectional areas, it does you very little good to use lets say, AN#8 or half inch fuel lines if the internal cross sectional area of the connections and fitting used with those lines is only 3/8" or smaller in cross sectional area,this is an area where dealing with a local hydraulic supply shop that has the correct tools and fittings to custom fabricate your fuel lines, coolant or lubrication lines is a very good idea!
talk to a local professional at your local hydraulic supply, measure accurately, take the time to explain what your trying to accomplish and take several pictures to show them what your doing, and get them too fabricate any high pressure fuel or coolant lines and related fittings




Up to 45 GPH= 3/4 GPM = 5/16" or -04 AN
Up to 90 GPH = 1.5 GPM= 3/8" or -06 AN
Up to 250 GPH =4.2 GPM= 1/2" or -08 AN
nearly ideal for transmission and oil coolers :D
Up to 450 GPH =7.5 GPM= 5/8" or -10 AN
Up to 900 GPH = 15GPM 3/4"or -12 AN






keep in mind that thats the minimum required, a fuel system has restrictions to flow rates like filters ,fitting and internal line flow restrictions requiring you to have a slightly higher actual supply volume and pressure
I used a earlier version of this fuel pump on my last carb race car

any electric fuel pump location, should be as close to the tank and as low as possible, having the pump gravity fed from the tanks a big help because electric pumps PUSH fuel FAR more efficiently than they can draw or suck fuel, if it takes much resistance to get fuel to flow to the electric fuel pump feed its almost always going to cause some problems.

in an ideal install you'll frequently use a factory made baffled fuel cell to replace the original and use an internal mount fuel pump that allows fuel around the pump to cool the pump and provide a far more efficient fuel supply
read this thread
and use the calculator


if you choose to add a weld on sump don,t cut a huge sump size hole is reduces tank structural strength, this picture suggests drilling large holes in the tank floor before welding on the sump, Ive found 3-to-5 1/2" holes rather centrally located over the sump and AN#8 fuel lines are all thats required even on an 800hp big block car




now many guys do find that its much cheaper to weld a sump to an existing fuel take and modify it for a larger external mount electric fuel pump


before you get crazy chasing some problem your sure is an intermittent fuel delivery issue
(1) Do a compression test!
(2) verify your ignition advance curve, and verify the ignition systems working correctly , the spark plugs are new, properly gaped and the ignition wires in excellent condition visually and with an OHMS meter.
(3) adjust your valves, correctly
(4) carefully verify theres no vacuum leaks, in lines or gaskets
(5)Check the fuel delivery system, WITH A GAUGE, while the engines under real operational inertial loads to verify you have a consistent 5-6 psi at the carburetor inlet port
(6) change out the fuel and air filters, especially if over 3-4 months old
(7) actually check your exhaust back-pressure levels
(8) verify your return style fuel pressure regulator and fuel lines function as intended
(10) actually look for and read installation instructions and rated flow and pressure limitations on fuel pumps and filters
(11) If ALL of the above are normal, only then start looking at the carburetor, and tuning issues

I think most guys would be amazed at how often, a high flow water separating fuel filter installed near the fuel tank that,s being checked and drained, with the filter medium changed regularly will cure or prevent a good many TUNING ISSUES ... 68213.html


38fit3.jpg ... m_sbs_sg_2 ... d_sbs_sg_1

fuel injection usually requires a 40psi plus fuel pressure, the line size and the fuel pressure regulator will have a big effect on your results, theres some threads and calculators above that will help,
generally a 110-150 gph pump and 3/8" / AN#6 lines minimum ,works fine up to about 550- maybe even 575hp, IN A FEW CASES with carbs BUT above that POWER LEVEL Id suggest a 1/2 AN#8 line

yes I know you don,t want to read the linked info and use calculators.....its mandatory if you want correct ... _Pump.html

read thru these threads carefully ... l-pressure ... g-140.html ... 1.htm#FPHP


viewtopic.php?f=55&t=7787&p=34866&hilit=stainless+fuel+lines#p34866 ... ciency.htm










viewtopic.php?f=55&t=231&p=275&hilit=+fittings#p275 ... ewall.html



as a rough guide, and assuming your running a carb engine with the correct fittings and fuel pump etc
this is about the max hp those fuel lines can be expected to support

AN4 (5/16")=375hp
an6 (3/8")=575hp
AN8 (1/2")=850hp

if your running a return style fuel pressure regulator it depends on the instructions that come with it and the number of ports,its usually mounted AFTER the two carb inlet fuel feeds
the pump feeds the fuel log, the fuel log feeds both carb inlets and the regulator mounted on the far end of the fuel log from the fuel feed bleeds off excess pressure to the return line to the the tank.

but on some models its mounted just before the fuel log on the port labeled "CARB" and the two other ports are labeled "feed" for the pump and "RETURN", for the return line

Assume a BSFC of 0.55 and gasoline at 6.25 lbs/gallon: BFSC Brake Specific Fuel Consumption

horse power x 0.55 = pounds of fuel burned per hour


600hp x .55=330lbs
330lb /6.25lbs per gallon=52.8 gallons an hour minimum fuel used.....keep in mind pumping loss thru the lines , inertial loads and heat can easily reduce actual flow rates by more than 50% so if you require 50gph your unlikely to meet demand with less than a 100-120 gph pump even with the correct line sizes
[/b] ... ncies.html

HERES SOMETHING FAR SUPERIOR, to stock fuel filters if you need something better
25-201BK_exploded_500.jpg ... ilter-1212


Machined from 6061-T6 aluminum and hard anodized black
Flows up to 12.32 gpm @ 45 PSI and 2.63 gpm @ 6 PSI with -10 port fittings
Filters as low as 7 microns
Viton o-rings and gaskets ensure outstanding performance when using gasoline, alcohol or gasoline/alcohol blended fuels
End caps are machined with -10 AN female fittings with o-ring receiver groove
End caps have pressure intensifiers for greater sealing of end gaskets
2” OD x 10” length for easy mounting
Commonly available replacement filter cartridges
Laser etched with AEM logo, flow and filter replacement information

The AEM High Flow -10 AN Inline Fuel Filter is CNC machined from 6061-T6 Aluminum and Hard Anodized Black. AEM’s engineers designed this filter with the racer in mind and with the intention of maximizing flow, filtration and ease of installation. The end caps are machined with -10AN female fittings with o-ring receiver groove that allow the filter to flow up to an astonishing 12.32 gpm @ 45 PSI and 2.63 gpm @ 6 PSI. All sealing o-rings and gaskets are made of Viton for outstanding performance when using gasoline, alcohol or gasoline/alcohol blended fuels. The commonly available replacement filter cartridges filter as low as 7 microns. The standard 2” OD allows for easy mounting virtually anywhere in the vehicle.
read thru the links and sub links





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Staff member

heres a chart on Holley electric fuel pumps ... 7914-3.pdf

if you super charge or use turbos read this,1667.html

Fuel Type:
Gasoline | Alcohol
Filter Material:
Stainless Steel Mesh
Overall Length:
Overall Diameter:
Material Type:
MFG. Part #:
Sold in Quantity:
Stainless steel filter is 3.75" long, 1.60" OD, and .80" ID.
Compact design offers weight savings over full size filter. Comes with stainless steel high-flow element. Can be cleaned and reused. Purple anodized aluminum housing. NOT compatible with ethanol (E85).

Available with -6 AN, -8 AN, -10 AN, or -12 AN inlet/outlet.

lets say youve got a 450 hp sbc and your looking for a decent mechanical fuel pump, the choice is between two in your catalog , one pumps 35 gallons per hour and one pumps 80 gallons per hour, but costs a bit more, so you want to know if the smaller pump will work?


The average advertised weight of a gallon of premium fuel is 6.34 lb/gallon.
Brake Specific Fuel Consumption or B.S.F.C.
Brake Specific Fuel Consumption or B.S.F.C. is the amount of fuel required to produce 1 HP for 1 hour. This means that an engine with a B.S.F.C of .5 will burn 1/2 or .5 lbs of fuel to produce 1 HP for one hour. Determining exact B.S.F.C for a specific engine is complicated and requires an engine dyno.
Based on industry standards the B.S.F.C for:
Normal Aspirated Engines is .45 - .55
Supercharged Engines is .55 - .60
Turbocharged Engines is .6 - .65

need to calculate fuel required:
Target Hp * B.S.F.C. = Fuel required in lbs/hr
450 *.6 = 270 lbs/hr
Most fuel pumps flow rate is advertised in gallons per hour:
Lbs/hr / fuel weight per gallon = gal/hr
270 / 6.34 = 42.6 gal/hr
but remember pump losses, and a fuel pressure regulator and a return line fuel feed system designs flow requirements ?
well on a mechanical fuel pump that supplies about 7psi at the pump, getting more than 4-5 psi at the carb, under hard acceleration is going to be a challenge, due to flow restrictions, pumping losses, etc. youll find that the 80 gallon pump matched to a quality fuel pressure regulator,is about the minimum required, and a 100-110 gallon flow at 7 psi would be a nice option




fuel .fuel .-fuel feed into fuel rail& injectors. then out too....fuel pressure regulator...then too..return line to fuel tank


it might help if you think, fuel pump provides fuel flow volume,
fuel pressure is a measure of resistance to fuel flow,
the fuel pressure regulator acts as a valve that opens if the pressure exceeds about 42 psi (YES some versions like yours are manually adjustable) but the reason its there is to maintain a consistent 39 psi-42 psi to do that you allow the fuel pump to stack or pressurize fuel in the fuel rail and in theory the fuel pressure regulator only allows excess fuel volume to flow back to the fuel tank through the return line if that fuel pressure exceeds the 42 psi, the pump is designed to provide a bit more than the required 42 psi too insure fresh cool fuel is cooling the fuel pump while maintaining that consistent fuel volume at the fuel pressure, when you tromp on the throttle the flow of fuel drastically increases, the regulator momentarily restricts out going fuel to maintain the fuel rail pressure and volume, until the flow demand drops enough, for excess volume and the resulting increased pressure that results to open the regulator again,

if your, looking at the diagram,and asking what pressure the fuel rail feeding the carburetor is pressurized too its obviously controlled by the fuel pressure regulator just beyond it in the diagram, which is usually located near the carburetor and fuel rail, to maintain the indicated 5psi, beyond that is the return line feeding back to the fuel tank and that should be close to zero, the main feed line from pump to the first fuel pressure regulator which ideally is located on the inner front fender or firewall maintains the 8psi-12psi the fuel pump provides , keep in mind a fuel pressure regulator can only control the pressure between it and its pressurized feed source, by bleeding off pressure above the peak its set for, it has zero control past it, it only controls pressure between it and its pressure feed source ,in that diagram the first fuel pressure regulator is NOT mandatory in some applications, its the use of the secondary nitrous feed that makes it useful in the depicted application

this basic fuel system, and line size will work to over 650hp or more with the correct pump and regulator, youll want a MINIMUM of AN #6 or 3/8" fuel lines on both the feed and return lines on a 450 hp engine
We’ve created three abbreviated charts pulled from Aeromotive’s data. These pressure drop charts are based on rubber-lined AN fuel hose. If you were to use hard line or smooth PTFE line, the pressure drops would likely be slightly lower. Note the major effect hose length has on pressure drop. While hose diameter is critical for volume, it’s obvious that length adds to the load that the fuel pump must support.

A quick way to equate lbs/hr to horsepower is to divide flow by the bsfc. Example: 600 lbs/hr / 0.50 bsfc = 1,200 hp. This example uses a normally aspirated, gasoline bsfc. As you can see by the charts, it would not be wise to plumb a 1,200 lbs/hr system with -8 line through 15 feet since that would generate a fuel system pressure drop of 14 psi.

Clow also pointed out that making the fuel line too large as an over-compensation for pressure drop can also cause problems. He mentioned that some big race teams have discovered that oversized fuel lines/fuel rails can kill flow velocity, which should be 3 to 12 feet per second on the pressure side of the system. An overly large fuel line will develop excessive fuel pressure fluctuations. Big may be good, but bigger is not always better!

One further check to ensure the fuel system operates at maximum efficiency is to pay close attention to the electrical side of the pump. As you can imagine, amperage demand also increases with higher fuel pressures. This places an increased load on not only the charging system to supply the necessary current and voltage; it also requires reviewing wire gauge to ensure it can handle the current and prevent voltage drop to the pump.

The above chart lists the wire gauge size recommendations depending upon the combination of the pump’s current draw and the length of the wire running from the power source to the pump. This chart assumes no more than a 3-percent voltage drop. Always use the same gauge wire for the ground circuit.

We’ve included a chart listing Aeromotive’s brushless pumps all pushing against a 60-psi head pressure. The smallest of the pumps requires just over 11 amps while the big pump spikes the load to 24 amps. At full song it might be necessary to employ a charging system capable of 100 to 140 amps to handle ignition, fans, accessories, and the fuel pump to ensure the voltage remains stable.
Once the charging system is spec’d, even a small pump demanding 20 amps over a 15-foot length of wire will benefit from an 8-gauge wire to minimize the voltage drop. The best way to ensure the entire system is sized properly is to perform a dynamic voltage drop test. This could be done with a volt meter, or better a data recorder monitoring the voltage at the fuel pump under max load. If the voltage drops below 13.5 volts yet it shows 14.3 volts any other time, you then know you have a 0.80-volt loss and there is work to be done to bring that drop closer to 0.40-volt or less.

In Conclusion

Maintaining voltage at the pump is critical since voltage is torque to an electric motor and torque is what keeps the pump from slowing down as pressure rises. Aeromotive pump flow curves plot both 13.2 volt (battery only) and 14.4 volt (alternator-equipped) applications. It’s obvious looking at the flow curves that keeping voltage at 13.5 volts or better is important to maintain expected fuel flow volume. Of course, higher voltages (14.5-16.0 volts) will make the pump run stronger. This is the idea behind voltage-boosting boxes that bump the system voltage to the fuel pump. While this does increase pump output, it comes at the price of reduced pump lifespan.

While it may appear that choosing a fuel pump is a complex process, hopefully we’ve illustrated that it’s not black magic and that with careful planning you can design an efficient fuel system for virtually any engine. Making power means paying attention to the details. When that happens, your efforts make success look almost effortless.
related links ... ciency.htm





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Staff member ... 0_5250.pdf

if you super charge or use turbos read this


Electric fuel pumps SHOULD be mounted, inside the cars frame rails for protection in a crash, and ideally lower than the fuel tank if its possible, because electric fuel pumps PUSH fuel far more effectively than they PULL fuel from the tank.
even a minor restriction or the need to pull fuel from the tank to prime the pump frequently results in in far lower fuel pump life because a dry pump, gets hot and wears faster as fuel flow generally cools the pump motor.if your pump can,t get cooled it tends to wear out much faster, thats also why IN TANK FUEL PUMPS last much longer if you never let the tank get below 1/4 full. as sloshing fuel cools an intake fuel pump along with fuel flow.
in an ideal set-up that includes a sump and/or fuel cell.
mounting a fuel pump in the trunk invites fuel leaks and fires that could easily transfer rapidly into the drivers compartment
return style fuel systems tend to have fewer problems and more consistent fuel pressure for similar reasons








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I left my walbro 255lph high pressure EFI pump in my tank, i ran 3/8" hardline to my firewall and then -6an braided line to my regulator, then have two -6an braided lines coming off regulator (each line has own port on regulator) to the carb. Then i have -6an braided hose to 3/8" hardline back to the stock tank.

Engine is a 521cuin big block ford in my 1987 formula 350. Fuel pressure is set to 7psi and has a 950 holley double pumper. Car has been running successfully for about 2 weeks now but hasnt been on the road. the 521 should make 550hp minimum and more tq by 5500rpms.

My friend says that my pump doesnt flow enough to feed 600hp, i checked the pump and the 255lph pump should flow about 60-70GPH, and i tested my pump by taking the lines off the carb and putting the gas into a bucket to measure. running through the regulator, the pump ran for 60s and pumped out about 1.5 gallons. which makes it a 90GPH pump. Now From what ive read is that 140GPH pumps are the minimum for 600hp and that a 12s car in the 1/4 will need to pump 2.5 gallons a min to support that amount of power. My motor has 10.7:1 comp and runs 93 octane.

So can someone clarify is my pump is not enough for my motor? and how much power is it capable of supporting? I figured its able to handle 800HP forced induction EFI so for carb is should be fine at 600hp?

engine has been running fine and if anything is alittle rich 12.5/13:1 A/F at idle and some throttle spikes seem fine as well, sounds healthy.

keep in mind as resistance to flow (pressure) goes up, the VOLUME tends to drop, 600hp probably doable , supporting 800hp is very unlikely, especially with an6 line size ID say darn near impossible ... ter-NN.pdf

Assume a BSFC of 0.55 and gasoline at 6.25 lbs/gallon:

hp x 0.55 = pounds of fuel burned per hour


600hp x .55=330lbs
330lb /6.25lbs per gallon=52.8 gallons an hour minimum fuel used

yea thats what i calculated.

"They said that to calculate for a return style regulator pressure to reduce free flow output of the fuel pump you use the following formula. MAX HP x .17= "pump free flow"

figure 550hp x .17 = 93 GPH free flow.

SO why does everyone Think that you need a 140GPH pump for like 500hp.

because the flow loss thru most fuel systems and restrictive filters and fittings reduce EFFECTIVE FUEL DELIVERED by about 50%, and if you measure flow at operational pressure you loose maybe 20% if you need 60gph you better be using AN8 or 1/2" lines and be pushing significantly more than 60 gph to the engine.


Staff member
STEVE/636C2 posted this info

"Hi-Volume Mechanical Fuel Pump Testing
The following is a write-up on some fuel system tests that I performed on my 1967 542” tri-powered stock-appearing Corvette with cast iron exhaust manifolds. Back in November of 2011 I posted a thread about the car making 671 rwhp on a DynoJet chassis dyno. After reading a thread by Alan Rothman that was based on him being concerned about the fuel system on his 10 second 127+ mph ’71 Corvette, I decided to run some tests. I was concerned that my Holley 12-454-25 170 gph pump might not be up to the task.

Just for arguments sake let’s say that my motor produces 800 hp at the flywheel. When you multiply that number by a BSFC number of .45 lbs/hr(estimate) and then divide it by 6.2 lbs/gallon for gasoline you would come up with a fuel requirement of approximately 58 gph at WOT. I have heard that you should select a pump with a free flow rating that is at least twice what the motor can actually consume. This would mean that I would need a fuel pump with at least a free flow rating of 116 gph. The Holley I am using should be more than sufficient based on their published numbers. But I had to try to find out for myself.

The system I had in place at the beginning of these tests is described as follows: the 3/8” pickup at the gas tank is attached to a 3/8” ball valve which connects to the 3/8” fuel line (about 11 feet long). The fuel line connects to the inlet side of a Holley 12-454-25 170 gph mechanical fuel pump with a -8 Fragola Push-Lite fitting. Another -8 Fragola Push-Lite fitting is attached to the fuel pump outlet and from there it goes into the Tri-Power 3/8” hard line (about 3 feet long) up to the first of two fuel blocks. The 3/8" fuel lines go from the fuel blocks to the carburetor bowls. The factory sintered fuel filters are used in each carburetor bowl. No regulator is used with this fuel pump and the fuel pressure is pre-set by Holley to 7.5 psi. All hard lines are 100% stock.

I modified this somewhat to enable the testing while the motor was running – a requirement for a car with a mechanical fuel pump. I disconnected the 3/8” fuel line that leads up from the pump to the first fuel block. I attached one leg of a 3/8” ‘Y’ fitting to this line. Another leg of the ‘Y’ goes to the factory fuel block and the final leg goes via 3/8” rubber hose to a 3/8” ball valve that hangs under the car. I have this car on a 4-post hoist that connects to a DynoJet chassis dyno with all the testing going on underneath. From the ball valve I have a 6” piece of 3/8” ID hose that allows the fuel to be directed into a 1 gallon container. The ball valve gives me the on/off capability.

The first series of tests involved the Barry Grant style 1-gallon test. Essentially the BG 1 gallon test is a measurement of how much time it takes to fill a 1 gallon container with fuel as delivered to your carburetor(s). His site states that a 12 second car should fill the 1 gallon container in 35 seconds, 30 seconds for an 11 second car, and 25 seconds for a 10 second car. I ran the first 2 systems twice and the third was run 3 times. All tests were performed with the Holley 12-454-25 mechanical fuel pump. For #2 and #3 the existing fuel system up to the Holley pump was eliminated with the 12’ of hose/line coming directly out of a 5 gallon container and feeding into the Holley pump. All tests are run at 1000 rpm:

System 1: Original (as described above) fuel system = 38 seconds (95 gph)
System 2: 3/8” ID rubber gas hose appx.12’ long feeding from 5 gallon jug = 38 seconds (95 gph)
System 3: ½” ID rubber gas hose and ½”OD steel tubing from 5 gallon jug = 38 seconds (95 gph)

This was a real eye opener. This test confirmed Rick’s (540 Rat) statement to me about 3/8” OD fuel line not being a restriction. I contacted Rick with regards to this testing because of his engineering background. I would like to thank him for all of the invaluable information he provided me with. Since it took 38 seconds to fill the 1 gallon jug that equates to a flow rate of approximately 95 gph – and that is at idle. That is well over the 58 gph that my motor requires. I then ran this test at 3000 rpm and the times were identical.

I also performed a test similar to System #2 with 3/8" rubber hose and an Aeromotive 140 gph electric fuel pump that operates at 14 psi. With no regulator attached and the pump back by the 5 gallon jug, it took 25 seconds to fill the 1 gallon container which equals 144 gph. With their regulator installed at the front of the 12’ hose and set to 6.5 psi it took 35 seconds to fill the 1 gallon container which equals 103 gph. This test was run just for comparison sakes.

The next series of tests were performed as a “flowing fuel pressure” test. I use this “flow gauge” when I am setting up the nitrous on my 632 car. The device is pictured here: http://www.appliednitroustechnology....flowguage.html. It is used to set fuel pressure based on the real demands of your nitrous jetting. There is a jet that fits into the end by the gauge that is based on the jetting you are currently running. You turn on the fuel pump while the end of this device is flowing fuel into a container and you can accurately set your flowing fuel pressure. I thought this might be a good test of what is happening under WOT demands so I connected it to the end of the ball valve.

I calculated the area of each .110” needle and seat and multiplied that value by 3(Tri-Power, remember) then calculated the needed diameter to match that area as approximately .190”. I placed a .190” jet into the end of the flow gauge. I ran each of these tests multiple times with the results being very close and, unfortunately, very dismal. The fuel pressure before the flow gauge was opened up was around 7.5 psi with all three of the above outlined systems. When the flow gauge was opened up the pressure dropped on all three systems to under 1 psi. I would have to think that these numbers would be even worse when the car is making a quarter mile run.

Again I ran these tests at 3000 rpm and again the results were identical. Clearly this current fuel pump setup was not up to my expectations or requirements.

Rick had been insisting that I needed a fuel pump that provides at least 14 psi instead of the 7.5 psi that mine had. I would then need a regulator to dial it back for the carburetors. I resisted because I absolutely have to have this thing looking stock when you open the hood. A regulator up by the carburetors will not work. After the above testing results I realized I had to make some modifications. I purchased a Holley 12-704 regulator and decided to try to shim the spring in the Holley fuel pump to increase the pressure. The regulator and all the extra plumbing is hidden under the car and can not be seen from the engine compartment. While I am sure that it would be better to have the regulator closer to the carburetors it is simply not going to happen in my case.

In order to verify my next rounds of testing I installed a Racepak Ultra Dash with data acquisition capabilities. I am now able to monitor and record data from the following sensors: rpm, voltage, oil pressure, oil temperature, water temperature, fuel pressure prior to the regulator, and fuel pressure at the carburetor bowl.

I disassembled the pump and machined 3 spacers (.100”, .150”, .200”) that would allow me to shim the pressure spring. Using a valve spring tester I recorded the spring pressure at two different spring heights for the spring with no shims and for the spring with each of the 3 different sizes. I wasn’t sure what thickness of shim I could get away with without risking damage to the pump so I decided to install the .150” first. While the pump was disassembled I also internally ported the inlet and outlet housings hoping to increase the flow a little.

These changes resulted in a fuel pressure prior to the regulator of 10.5 psi with fuel pressure at the carburetor bowl adjusted to 6.0 psi. I wanted at least 14.0 psi prior to the regulator. Since this .150” shim only increased the pressure by 3.0 psi, I didn’t want to spend any more time testing the other shims. At this point I decided to eliminate the idea of using shims and ordered Holley’s high pressure spring assembly.

Once this diaphragm assembly arrived I installed it in the pump and was rewarded with much higher fuel pressure. At 900 rpm the fuel pressure prior to the regulator was 16.0 psi while the fuel pressure at the carburetor bowl was adjusted to 6.5 psi. At 2000 rpm the fuel pressure prior to the regulator jumped to 17.0 psi while the fuel pressure at the carburetor bowl remained at 6.5 psi. Now I felt I was getting somewhere.

I ran the BG 1 gallon tests with the motor at 900 rpm and at 2000 rpm. I also decided to run the BG 1 gallon test with the flowing fuel pressure assembly attached – a test I had never tried before. Attaching that flowing fuel pressure assembly to the end of the hose would cause a significant restriction and should result in a longer time to fill the 1 gallon container. The following is a summary of the results:

.................................................. ...............................900 rpm……………...2000 rpm
BG test with 6" of -6AN hose after ball valve:.....45sec / 80 gph............34sec / 106 gph
BG test with .190" jet after ball valve:..................50sec / 72 gph...........37sec / 97 gph

Again, I was very happy with these results. At 2000 rpm the time to fill the 1 gallon container was now the same as the electric pump. When the .190” jet was added to the equation it only took 3 seconds more to fill that same 1 gallon container. This time increasing the rpm had a definite and positive impact.

The final set of tests were based on the flowing fuel pressure assembly. The following are the results :

.................................... 900 rpm....... 2000 rpm
Pressure after pump:.....4.5 psi.............5.5 psi
Pressure at carb bowl:...2.0 psi.............3.5 psi

The increase in rpm again had a positive effect especially on the pressure at the carburetor bowl.

Do these tests have any real-world validity? I sure hope so but the final proof will come when I take the car out to the drag strip.

Steve "



Staff member
IF YOU HAVE A GOOD DEAL OF SPARE CASH, AND YOUR DEAD SET ON A MECHANICAL FUEL PUMP, holley sells 170 GPG and 200 GPH pumps but they are darn expensive and ALL OF THEM require a return style fuel pressure regulator and AN # 8 lines ... /overview/
this holley pump has the AN#8 size ports ... -1rev1.pdf

one factor I see guys ignore at times is when a in tank fuel pump goes bad, guys read the instructions about dropping the fuel tank to get access to the in tank fuel pump to replace it, which in some cars makes the replacement procedure a HUGE P.I.T.A. and start thinking ,...hey Ill just tap into the fuel line and install one of the outside mount electric fuel pumps and avoid all that work, FORGETTING that the defective in tank fuel pumps going to significantly restrict fuel flow, as its still in the fuel line in the tank



the AN#8 or 1/2" inside diam. fuel lines and a decent fuel cell would be required along with the correct fuel pressure regulator to use these pumps, remember you can calculate the size fuel pump required, but the pump, used to feed the system and return lines the tank or fuel cell design and the fittings used the length of the lines ,will all effect the flow rates youll get
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Staff member
I helped sort out a tuning issue on a friends chevelle yesterday ,the problem was that he assumed that he knew what was going on in his engine but failed to actually do any testing. his car had a symptom that should have raised a few mental red flags, yet he ignored the rather obvious evidence and assumed he knew the cause without testing.
Heres what happened,
he had a 350hp 396 bbc in a 1967 chevelle that he had recently rebuilt with a rather radical flat tappet cam, a new EDELBROCK rpm oval port intake and a 780 cfm carb, new higher compression pistons, and a new off brand, import manual fuel pump he got from a local auto parts store. on hard acceleration the car would start blowing black smoke out the exhaust, which obviously indicates a rich fuel/air ratio, but if you hooked a fuel pressure gauge to the carbs fuel inlet line with a tee under the hood and revved the engine the pressure didn,t seem to jump much. and the fuel level in the carb seemed to stay consistent and not flood.
he was not running a fuel pressure regulator with a return line, just a fuel line to the pump on the block from the rear fuel tank, and a line from the pump to the carb inlet port, with a small fuel filter mounted next to the carb.
I convinced him to mount a test gauge on the carb inlet port after extending a 6 ft section of fuel line so the gauge could be observed from the pass seat,with a passenger watching it while he ran thru the gears,while the car was under acceleration, as a test, what we found was that the pressure started out at about 6psi but under hard acceleration, it slowly climbed to 11 psi, but dropped rapidly if the engine rpms dropped.
IT looked very similar to this fuel pump
I convinced him to add a return style fuel pressure regulator and return line to the car, as a test, but because he was very reluctant to run the return line back into the fuel tank,or spend the cash on a fuel pressure regulator until he was sure that would cure the problem, we ran the spare return style fuel pressure regulator I had on the shop shelf, to a 3/8" barb brass tee fitting mounted on the inlet side of the pump, from the return style fuel pressure regulator we temporarily mounted on his pass side fender skirt, just to test the idea, that adding it would cure his problem.
and yes it did! BTW this is not that common in my experience, in fact Ive seen several manual fuel pumps that failed to pump enough fuel at higher rpms that cause an engine to starve for fuel or go lean, rather than build to much pressure, but the key here is taking the time to test and verify whats going on rather than guessing.
and yes once I proved the problem and its cure hes ordered the fuel pressure regulator and fuel lines and fittings so hes going to do the modifications required as soon as the parts needed arrive


fuel pressure and fuel flow volume are two totally different factors
the needle/seat, in a carbs float bowl,controls the fuel level by opening and closing the needle valve, in the fuel bowl, and its designed to and generally can control fuel inlet pressures below 8 psi, the manual fuel pumps designed to supply a constant 6-8 psi in most cases
(but generally works best at 5-6 psi)volume of flow only come into play once the needle valve opens and that relates to how quickly the floats being raised back to the point the needle seat closes




the normal manual fuel pump supplys a fuel pressure at the carb inlet port that can and probably does vary from 6-8 psi, the carbs needle valve will allow fuel to flow into the fuel bowl when the fuel level drops enough to allow the needle valve too open, the potential flow volume has little effect on the carb AS LONG AS ITS SUFFICIENT to keep up with demand and supply the carb with more than enough fuel to allow the floats to shut the needle valve when the carbs fuel bowls fill, having a surplus potential flow volume hurts nothing as long as the pressure can,t over come the floats weight ant push open the needle valve, having LESS than the required flow volume when the fuel bowl float is allowing the needle valve too fully open results in a lean miss fire at higher rpms
yes there ARE some aftermarket manual fuel pumps that produce 15 psi that will flood a carb, without a fuel pressure regulator with a return line design, in use.
you might want to read thru these links and sub links, for related info , each link might be useful






viewtopic.php?f=55&t=211 ... ewall.html

allen said:
grumpy my original mechanical fuel pump failed on my chevelle, so I removed it, screwed on a block off plate and added a carter electric fuel pump I had sitting on the shelf that looks like this one
the car runs fine until you accelerate hard, then it breaks up once it hits 2 gear , that to me indicated its running out of fuel, do I need a performance fuel pump rated at 110gph or one rated at 130gph, as I have zero idea what the original mechanical pump was rated at?

theres a great deal of info in the links below, the problem many guys have is in not understanding that they need a return style fuel pressure regulator a decent filter and adequate line sizes once they start boosting power levels well past the original rated power.
a fuel pump might be rated at 110-gph or 130 gph but once you start restricting the intake and exit ports there's a very noticeable drop in the actual effective flow rate, a 130 gallon per hour pump will be needed to flow 55-75 gph, actually reaching the carburetor inlet port,thats required in many cases, once the restrictions and inertial loads in the fuel lines, and filter etc. are calculated, and a return style fuel pressure regulator makes the system pressure and volume far more consistent and dependable, a 3/8" line size is usually adequate up to about 525hp, once you go past that Id strongly advise swapping to 1/2" or AN#8 line size but remember the weak link in the chain, concept, it does you zero good to have 1/2" lines if the interior openings in the adapters, you use on the lines or filter or fuel pump, etc. or the fuel line exiting the fuel tank is a 3/8" or smaller size. and installing a fuel filter that has 3/8" in and out lines thats rated at lets say 60 gph is certainly going to restrict flow regardless of the fuel pump used. I see guys that spend decent cash on a 130 gph fuel pump who then install crappy fuel filters like these, (pictured below) that were never designed for a performance application or hook up a performance engine, they expect to produce 500 plus hp, they built, to the original 5/16" or 3/8" internal fuel line from the tank.
you DO understand that theres a very visable and meassurable difference between a O.E.M. style replacement fuel pump, designed as a replacement part that can be swapped in, that might provide a bit higher flow, and a true performance aftermarket electric fuel pump. right?
any serious fuel delivery system will require a fuel cell, or major changes to an existing fuel tank, and larger diameter fuel lines and a better fuel filter aling with a matched return style fuel pressure regulator and return lines, you can,t simply swap in a few components the whole system, (end to end) will need to be upgraded if you expect relieable fuel delivery by the time your exceeding about 550-600 hp.!/Pumps/c/14136041/offset=0&sort=normal


only to experience fuel starvation issues , who act clueless as to the potential cause.
if you expect to maintain a solid 500hp or higher engine output level, your going to find that a 3/8" stock fuel line, fuel filter,fuel tank lines and strainer sock assembly is very likely to cause fuel starvation issues under sustained fuel demands at that power level, your also very likely to find the stock fuel pump , won,t keep up with demand


you will be amazed at what youll learn reading links[/b]




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Staff member

look at the chart above ,related to an edelbrock electric fuel pump, while that particular pump may not be what youll be using all electric pumps will be some what similar in that fuel volume and pressure output varies with current draw,and the stock alternator in most cars is semi ,marginal at supplying the required current under some conditions.
swapping from a stock 105 amp alternator to an aftermarket 180 amp-200 amp alternator has consistently made a noticeable difference in cooling fan speed and at times fuel pressure.
remember that on any turbo or super charged engine application the fuel pressure MUST be indexed to the engine boost, to maintain the ideal fuel/air ratio, and you'll generally want most engines to run in the fairly lean 14.7:1-13.5:1 range at idle but be tuned to transition smoothly and consistently, to a fuel/air ratio closer to about 12.6:1 as the rpms AND loads on the engine are increased,







it should be rather obvious that as the alternator current produced increases theres a potential for the the cars fuel pump output to increase ,especially if the current battery or alternator is marginal under full loads
one factor I seldom see being mentioned is that the alternator output in amps and volts has a very measurable effect on the cars electrical cooling fans, and electric fuel pump pressure delivered to the engines fuel rail, or carburetor inlet, especially if you don,t have a dependable return line style fuel pressure regulator and a fuel pump that easily provides more than enough pressure and volume of fuel at the minimum volts and amps the cars alternator and charging system provides.
Ive repeatedly seen the cooling fans run more efficiently and the ignitions run more consistently with a larger amp rated alternator.
Couple formulas:
Power(Watts(equipment rating))=Volts x Amps
Amps= Watts divided by Volts
Volts= Watts divided by Amps
READ THE SUB LINKS ... nt-output/ ... ulator.htm

check your alternator's current easily ,as its output-can be verified and tested, many auto electrical places and some like Autozone will load-test your battery and alternator for free with a heavy tester.

oil cooler fans

head lights

radiator cooling fans


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solid fixture here in the forum
just want to add that the AEM fuel filter above is actually a wix filter, part no 24003

and napa sells the same filter for 66 bucks, napa gold 4003. the aem is between 65-119 dollars depending on the source, but summit has the original wix for 45.


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Staff member
87vette70TA said:
Fuel Pumps
All fuel pumps are listed in horse power rating from least to greatest.

  • ... et%29.html"]A2007-A High Pressure (-8 inlet & outlet)
    Maximum HP: Internal Pressure Relief Valve
    GPH/PSI Range: 75-100 GPH/0-70 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder see part # A2005-A, D2032-A 2015 Series
  • ""]A2011-A Low Pressure (-8 inlet & outlet)
    Maximum HP: 600 hp Carb
    GPH/PSI Range: 95-100 GPH/0-5 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder see part # A2005-A, D2033-A or 2015 Series
  • ""]A2005-A (-8 inlet & outlet)
    Maximum HP: 650 hp Inj/800 Carb
    GPH/PSI Range: 65-90 GPH/ 0-90 PSI
    Considerations: If your actual horsepower is close to the Max Hp limit and/or you are considering a power adder, see 2015 series
  • ""]D2015-A (-8 inlet & outlet)
    Maximum HP: 1000 hp Inj/1050 hp Carb
    GPH/PSI Range: 85-115 GPH/0-160 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder see 2025 Series
  • ""]DB2015-A (-12 inlet and -10 outlet)
    Maximum HP: 1000 hp Inj/1050 hp Carb
    GPH/PSI Range: 85-115 GPH/0-160 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder see 2025 Series
  • D2033-A (-8 inlet & outlet)
    Maximum HP: 1400 hp Inj/1600 hp carb
    GPH/PSI Range: 180-190 GPH / 0-10 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, See Part # 2345-A
  • ""]D2032-A (-8 inlet & outlet)
    Maximum HP: Internal Pressure Relief Valve
    GPH/PSI Range: 140-180 GPH / 0-70 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, See Part # 2345-A
  • ""]D2025- A (-8 inlet & outlet)
    Maximum HP: 1400 hp Inj/1600 hp Carb
    GPH/PSI Range: 140-180 GPH / 0-80 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, see Part # D2035-A or 2345-A
  • ""]DB2025-A (-12 Inlet and -10 Outlet)
    Maximum HP: 1400 hp Inj/1600 hp Carb
    GPH/PSI Range: 140-180 GPH / 0-80 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, see Part # D2035-A or 2345-A
  • ""]D2035-A (-12 inlet and -10 outlet)
    Maximum HP: 1800 hp @ 14V, EFI and Carb engines
    GPH/PSI Range: 180-210 GPH/0-80 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a larger power adder, see Part # 2345-A

""]Aircraft Applications

Displaying 1 thru 10 of 18 Products. ""]Next Page >
87vette70TA said:
Fuel Pumps All fuel pumps are listed in horse power rating from least to greatest.

  • ""]2345-A (-12 inlet and -10 outlet)
    Maximum Horsepower
    2000 hp @ 14 VDC EFI (1000 hp on Methanol)
    2400 hp @ 16.5 VDC EFI(1200 hp on Methanol)
    GPH/PSI Range: 200-250 GPH/0-75 PSI
    Considerations: If your actual horsepower is close to the Max Hp limit and/or you are considering power adder, see part# 34706 or 34712 Mechanical Pump
  • ""]B2311-A (-12 inlet -10 outlet)
    Maximum Horsepower:3200 hp @ 14 V (1600 on Methanol)
    GPH/PSI Range: 340-370 GPH/0-30 PSI
    Considerations: If your actual horsepower is close to the Max Hp limit and/or you are considering power adder, see part # 34704, 34706 or 34712. If converting to Fuel Injection please see part # 2345-A or Weldon's Mechanical Pumps -- 34704, 34706 or 34712
  • ""]TC250-100, 2.5" Band Clamp
  • ""]34704 4+ GPM Mechanical Fuel Pump
    1.25 GPM, 13 PSI at 1000 RPM up to 4.8 GPM, 100 PSI at 4000 RPM, up to 2400 HP on racing fuel / 1100 HP on methanol
    [*] ""]34706 6+ GPM Mechanical Fuel Pump
    1.75 GPM, 13 PSI at 1000 RPM up to 6.8 GPM, 100 PSI at 4000 RPM, up to 3600 HP on racing fuel / 1800 HP on methanol
    [*] ""]34712 12+ GPM Mechanical Fuel Pump
    3.15 GPM, 13 PSI at 1000 RPM up to 12.45 GPM, 100 PSI at 4000 RPM, up to 6000 HP on racing fuel / 3000 HP on methanol
    [*] ... oller.html"]14000 Fuel Pump Controller
    Input: 12-16 Volts
    Amps: Up to 28 Amps
    Controller allows you to toggle between controlled and full speed
    [*] ""]"NEW" From Weldon -- Sportsman Fuel Pump
    Maximum HP: 1200+ hp Carburetted
    GPH/PSI Range: 150 GPH @ 28 PSI
    Considerations: If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, See Part # D2035-A or B2311-A

""]Aircraft Applications



Staff member
87vette70TA said:
As you can see, Aeromotive is a Joke compared to a WELDON.!store/r0nxr/!/Pumps/c/14136041/offset=0&sort=normal

DB2015-A (-12 inlet and -10 outlet) This pump is ideal for Hi-performance Street/Strip Cars.




Maximum HP:
1000 hp @ 14V EFI (500 hp on Methanol)
1050 hp @14V carb (525 hp on Methanol)
GPH/PSI Range:
85-115 GPH / 0-160 PSI

If your actual horsepower is close to the Max HP limit and/or you are considering a power adder, see 2025 Series


All billet body pumps are 100% serviceable/repairable
Self Priming

- Pump may be mounted above fuel cell
vertical or horizontal mount
Breakaway coupling prevents pump/motor damage in the event of contamination
All internal wear components are 100% metallic

No plastics or composite materials. Our internal pumping elements are made of high speed tool steel and bronze. This results in the longest lasting, highest quality, most durable pump available.
Body machined from billet aluminum
For carbureted or injected engines
Provides Consistent Performance with no fall-off in flow
Precise fuel delivery
Blades self-compensating for wear
5.5 lbs
Current Fluids

Weldon Pump offer the widest range of fuel compatibility.
Gasoline - Diesel - Methanol - Ethanol - Nitromethane - All racing fuels Comments
Requires appropriate bypass regulator, a -6 return line at a minimum is recommended.
Item is in stock.

Click the “Order” Button to add an item into your shopping cart.
Part # Description Price Qty. DB2015-A Fuel Pump $728.00

87vette70TA said:
[ ""]

""]"NEW" From Weldon -- Sportsman Fuel Pump

Weldon debuts the Sportsman Fuel Pump: their first hand-adjustable pump/bypass combination�lifetime warranty included Cleveland, Ohio: Weldon, the only racing fuel pump maker who uses all-metallic internal pumping components�no plastics or Phenolics permitted�has announced a new and innovative fuel pump with an integral bypassing regulator. Called the Sportsman, it is petite, light weight and supports race engines producing up to 1200 horsepower. Because its internals are made entirely of tool steel, including the pump ring, pump rotor, and pump vanes, the Sportsman�s inner working parts will neither fracture nor deteriorate with heat nor will its flow be impaired when fuel pressure is increased. Operating on 12 to 16 volts this 4.1lb fuel pump has impressive pumping power with surprisingly low amperage draw. Efficiencies in the pumping chamber have a decisive effect on reduced amp draw. Featuring AN-10 inlet and outlet ports and AN-8 bypassing port (all ports chamfered and counter bored for O-ring seals) the Sportsman boasts a Teflon diaphragm with a 1.7 sq. in. surface area. This diaphragm effectively reduces fuel pressure fluctuations and is compatible with all fuels. .
""]More Info


  • Our commitment to quality is unsurpassed in the industry. Our products don't just last for a few races or a few seasons, they last as long as you need them.
  • Our products are not disposable. After long periods of use, certain component parts may exhibit wear and require replacement. We offer replacement component parts for most of our product line.
  • Customer service is crucial to us. We realize it does us little good to manufacture the best products if we are not able to advise people on how best to use them. Call us at
    1-440-232-2282 or email us at to experience the Weldon difference.
  • One stop shopping. You can call us for advice on how to build your fuel system and then buy many of the necessary components.
  • Unique performance charts. Every pump we sell is flow tested and shipped with a chart showing the exact pressure vs. flow data.


Weldon Pump began in 1942 as a division of the Weldon Tool Company founded in 1918 by Carl Bergstrom. As WWII drew to a close, so too did Weldon Pump's production as the need for military pumps was diminishing. Revitalized by a creative and burgeoning aftermarket, Weldon Pump began production on pumps for general aviation. Business took off and peaked in 1979 with the production of over 12,000 aircraft pumps. 1980 brought about our first high performance marine application and the rest is history.
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solid fixture here in the forum
thought i would drop this in here... considering a setup similar to this for the ls motor... ... -044-combo

dual bosch 044's and these guys make a neat little manifold for them... however the manifold outlet is only a -6 so i think ill skip the manifold and use a -8 -8 -8 Y connection to run the supply line to one of the above mentioned WIX filters.

the filter is 3/4" NPT in and out so a couple adapers will be required to put that big sucker in line but i imagine itll work real good since its rated to 12 gpm of flow and both those pumps combined flow about 4 gallons per minute. it should handle the flow just fine. if i was going road racing i would consider this setup also in the trick bracket but probably use a surge tank in series instead of running them parallel... an alternative to the sump


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solid fixture here in the forum
the inlets are on the flip side of the pumps, and these are external, however i think bosch and walbro make good in tank pumps, that isnt gonna work in my application


The online Race speed shops on Fleabay I watch Grumpy have been selling out of Weldon Racing fuel pumps.


The Grumpy Grease Monkey mechanical engineer.
Staff member
read these links


Fuel Hose Sizes
AN SizeTube or Hose ODTube or Hose ID
-6 3/8” .297”
-8 1/2” .391”
-10 5/8” .484”
-12 3/4” .609”



Id point out carb equipped cars will generally require a 6-9 psi and if your trying to supply over 450-500 hp youll want AN#8 or 1/2" inside diam. size fittings
if its a fuel injection application, your generally dealing with 38-44 psi fuel pumps
but again if your trying to supply over 450 -500 hp youll want AN#8 or 1/2" inside diam. size fittings,
if you stick AN#6 or 3/8" fittings that restricts flow significantly
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