Fuel Pumps

Looking to solve a fuel starvation problem, I am running a 351 windsor with a Holley carb fed from a facet fuel pump, at 4500 rpm the facet pump can not keep up, result no fuel at the carb.
Are any of you running two pumps in parallel, would this be a solution, any other ideas welcome.
 

Randy V

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Mike,

Many people are running Facet pumps without issue. I'm not saying that it is of sufficient capacity and maybe you do need two of them in parallel. However, if that combination has worked well in the past but now it is not, I would first look to your fuel filters and possibly your fuel lines - even the braided ones as they will all start to break-down over time..
 

Seymour Snerd

Lifetime Supporter
Looking to solve a fuel starvation problem, I am running a 351 windsor with a Holley carb fed from a facet fuel pump, at 4500 rpm the facet pump can not keep up, result no fuel at the carb.
Are any of you running two pumps in parallel, would this be a solution, any other ideas welcome.

If by 4500 RPM you mean constant speed at 4500 RPM (i.e. light throttle) then there is something wrong with the pump. The easiest way to diagnose this is to disconnect the fuel line at the carburetor, point it into a container of a known size, and see how fast it fills up compared to the pump's rated output. If it's not at least half of that figure the look upstream for a problem.

That being said, if the facet pump you are referring to is the ~6" tall cylindrical one formerly known as Bendix, you should know that even Lamborghini doubled those up in order to supply 375 hp engines, so its easy for me to imagine it would not keep the float bowl full on a big V8 at high throttle. They are good for only about 35 gal/hr. However, driving around town it should be just fine all by itself. That pump should fill a gallon container in about 2 minutes.

The usual formula is 1/2 lb per hp-hour. Gas weighs 6 lb/gal. So you need 1/12 gal/hr/hp. At 360 hp that's 30 gal/hr so a single facet pump is on the raggedy edge.
 

Charlie Farley

Supporter
Alan,

You are what makes this forum so good.
Succinct, accurate advice.
Thanks
Not sure they all appreciate it though...
 
The facet pumps will cause a lean AFR with aggressive driving on a 351 with Holley. On a dyno the AFR will get lean enough to cause damage to the engine.

I wonder if it's possible to have both pumps (LH and RH) run at the same time? Provided the pipe diameter downstream of where they meet is of sufficient size this should supply enough fuel. Just an idea.
 

Seymour Snerd

Lifetime Supporter
Cliff raises a good point; a marginal fuel pump is really dangerous since it seems ok until that one time when you hold full throttle a little too long or whatever and you burn valves or pistons or detonate. Best to be conservative or at least put in a fuel pressure gauge and keep an eye on it.
 

Pat

Supporter
May be a stupid question but have you checked the float level, fuel filter screens, fuel pickup and the float chamber for debris? You may not be getting full flow. I've seen this happen when the fuel cell foam begins to degrade.
 
Hi, thanks for all your input, I have check the floats, filter and replaced the pump and fuel lines on one side, it was running on a dyno at the time 4200rpm 255hp, 319lb torque, about 155mph just don't want to damage the engine on the road
 

Randy V

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so Mike, the ten thousand dollar question is ~ did it ever work right or have you always had this problem?
 
Mike

easy test

detach the fuel line after your pressure regulator. if you don´t us a PR, than hook one up and set it to 5 PSI. THan put the hose in a reserve canister and measure how long it takes to fill up those 20 liters. A pump which i would percive as sufficient should manage this within 4 max 5 Minutes (75 gph against 5 psi). Everything else below i to less. Doubt that this POS Facets will be able to do that. Switch to a bigger pump. (Aeromotive or Holley Gerorotor).

By the way you have not confirmed that you did check the pick up as well. may be this is clocked.

TOM
 

Mike Pass

Supporter
Maybe check the rate of flow after the regulator. Sometimes the pump won't deliver the flow or the fittings or unions can restrict the flow. Checking what is actual coming out into your measuring container after the pressure reg is the only way to be sure. We have had two fuel flow issues. One was caused by crap in the filter when the pump system was a bit borderline. The other was a fuel union that needed opening out in diameter.
The big Holley 150 pumps will do the job and have internal regulation.

Cheers
Mike
 
We pump 20 litres in 2 minutes useing all aeromotive equipment ( pumps/filters/pressure regulator etc ), at 5 psi through all -8 pipes except final -6 lines to carbs. Frank
 

Seymour Snerd

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We pump 20 litres in 2 minutes useing all aeromotive equipment ( pumps/filters/pressure regulator etc ), at 5 psi through all -8 pipes except final -6 lines to carbs. Frank

In American that's 158 gallons/hr. :)

Regarding the Holley 150 pumps: how do they sound? I've got dual carter pumps fully rubber mounted, etc., and they still make an obnoxious growling sound.
 

Mike Pass

Supporter
Not run the Holley 150 pumps yet. Hope they aren't too noisy. If they are then it's out with the megaphone tailpipes again!
Cheers
Mike
 
Chuck is running the 125 gerorotor Holley pump and once answered me that he can hardly hear them running. My Aeromotive Vane pumps are quite loud , especially when they face the full back pressure and can not flow enough ( in idle).

Other than that the aeromotive equipment ( my whole fuelsystem, including filters and regulator is aeromotive and as on ranks setup lines are AN 8 except the last two after regulator to carb which ar AN 6.)
I have a set of 150 PH Holleys but not installed yet.
 

Jim Rosenthal

Supporter
The Holley pumps are LOUD. I have one in my Cobra, the red pump, and it makes a lot of noise. Then again, it is RIGHT behind where I sit in the car. I would think two Facet pumps would make a lot less noise, but I agree with the above that one Facet pump would not keep up with a decent size Ford V8.

Too bad (the old lament) that they won't make the SW pumps again. Those kept up fine, didn't they....
 
I had look at replaceing the pumps with Holley pumps but some are saying that they will not suck the fuel from the tank as they are mounted above the tank, Edelbrock also make a pump 6.5 psi 120gph(part no 1791) but again should be mounted below the tank. What areomotive pump are you running, do the holley pumps work OK.
The Edelbrock pump looks good and they say its quieter than most, but will it work.
 

Seymour Snerd

Lifetime Supporter
I would think two Facet pumps would make a lot less noise.
In my front-engined Lambo, where the Facet pump was mounted by the differential, you could hear the pump quietly ticking only with the engine off. When I rubber mounted it using the Facet kit, you could not hear it at all from inside the car.

With all this reminiscing about my Lambo's Bendix/Facet pumps, and complaining about my Carter 4070's noise, I'm going to replace the Carters with a pair of 36 gph Facets. Not only will they be quiet, but they have a built-in 70 micron fuel filter, and I believe I can join the two without check valves, thus significantly symplifying the plumbing on my car. And 72 gph should be plenty for 500 bhp. Great thread!
 
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