Looking for recommendations on electric fuel pumps
#1
Racer
Thread Starter
Looking for recommendations on electric fuel pumps
I am contemplating whether I should get rid of my mechanical fuel pump and replace it with an electric fuel pump. Has anyone else done it? What did you use and, most importantly, how and where did you mount the electric pump? I found this on the net which I found interesting: http://www.mechanicalcaveman.com/bes...l-pump-review/
#3
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You haven't given us reasons why you want to change so it might be nice to hear that. The changeover, done right, is a bit involved.
As to the best place, as a general characteristic, unlike the mechanical, electric pumps push better than they pull. So back of the car and under the tank. You can also modify the tank to have one installed inside the tank. That would tend to reduce the noise, as all the pumps are noisy.
You will need a relay to supply power to the pump and for safety's sake, some kind of mechanical switch that either detects loss of oil pressure or a g-sensitive switch. This is to shut off fuel flow in case of an accident. Nice thing about mechanicals is when the engine stops, the pump stops as well. These switches are easy to wire up and you can find directions easily enough.
They are all noisy, I had a Holley mounted up near the motor in a jury-rigged fashion, simple enough and it works, but not really ideal. My pump now is an Edlebrock and I have it mounted on the rear frame and over the muffler as you can see in the picture. Once the motor starts the exhaust drowns out the sound of the pump.
The way I have it mounted makes it accessible from under the car with the spare tire carrier removed.
As to the best place, as a general characteristic, unlike the mechanical, electric pumps push better than they pull. So back of the car and under the tank. You can also modify the tank to have one installed inside the tank. That would tend to reduce the noise, as all the pumps are noisy.
You will need a relay to supply power to the pump and for safety's sake, some kind of mechanical switch that either detects loss of oil pressure or a g-sensitive switch. This is to shut off fuel flow in case of an accident. Nice thing about mechanicals is when the engine stops, the pump stops as well. These switches are easy to wire up and you can find directions easily enough.
They are all noisy, I had a Holley mounted up near the motor in a jury-rigged fashion, simple enough and it works, but not really ideal. My pump now is an Edlebrock and I have it mounted on the rear frame and over the muffler as you can see in the picture. Once the motor starts the exhaust drowns out the sound of the pump.
The way I have it mounted makes it accessible from under the car with the spare tire carrier removed.
Last edited by ignatz; 01-21-2018 at 08:23 PM.
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Lagonia (01-21-2018)
#4
Racer
Thread Starter
#5
Race Director
Why do you want to get rid of the mechanical pump. If it is bad just replace it with another mechanical one and drive another 100K trouble free miles. It takes about an hour of time. To put in an electric is going to take a lot more time and money for no performance gains.
Just saw your next post. If the pump is bad replace it with a good mechanical pump.
PS I have run over 500 HP to 7000 rpm with a mechanical pump. Nothing wrong with a mechanical pump
Just saw your next post. If the pump is bad replace it with a good mechanical pump.
PS I have run over 500 HP to 7000 rpm with a mechanical pump. Nothing wrong with a mechanical pump
Last edited by Gordonm; 01-21-2018 at 09:36 PM.
#7
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I don't see the need in your case, but if I did change a 79 to an electric pump I'd likely use a 82 EFI pickup in the tank and put a TBI pump into it. Pick a brand like Walbro. Then, put a regulator under the hood to control the pressure to the carburetor.
If you are concerned about having it simply powered with the ignition on via a relay, there are ways to wire it so that it will only run when either the key is in the start position or there is oil pressure.
If you are concerned about having it simply powered with the ignition on via a relay, there are ways to wire it so that it will only run when either the key is in the start position or there is oil pressure.
Last edited by lionelhutz; 01-21-2018 at 09:36 PM.
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NewbVetteGuy (01-21-2018)
#8
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Forgot to mention regulation. With varying demands on the fuel supply, your pump will need to supply at WOT without dropping pressure as well as at idle and some sort of regulation is required to keep you at reasonable pressures. The Edlebrocks have two variations. From memory 120 GPH and internal regulation and 160 GPH and no regulation. I am pretty much in agreement with the other advice you are getting is you really oughta stay with mechanical and solve your starvation problem that way.
What is your HP and carburation setup? - Never mind, I see a lot of info in your other post!
What is your HP and carburation setup? - Never mind, I see a lot of info in your other post!
Last edited by ignatz; 01-21-2018 at 10:02 PM.
#9
Melting Slicks
I forgot people still used mech. pumps!
Today the cheapest way to fuel a 400 horsepower engine is the $89 walbro in-tank unit. Dime a dozen and very quiet, with the proper regulator it could be used in a variety of applications.
There are better pumps available also. Walbro also makes a "450" which supports far more than 400 horses. Same in-tank deal too.
All you need to use in-tank pump is:
1. A tank that supports an in-tank pump (it needs to hang in such a way that all fuel can be used up from the tank. They sell "hydramats" to help absorb and hold fuel in applications where the owner is retrofitting an electric pump into a tank not originally designed for one) The tank needs a feed and return line minimum.
The feed would goto a regulator. Vettes have a "filter regulator" mounted on the chassis which does both but I avoid them because they are not adjustable. Instead, mount a typical Aeromotive somewhere near the engine and plumb feed/return to it. Then from that regulator you can feed a fuel rail or carb or w/e
Today the cheapest way to fuel a 400 horsepower engine is the $89 walbro in-tank unit. Dime a dozen and very quiet, with the proper regulator it could be used in a variety of applications.
There are better pumps available also. Walbro also makes a "450" which supports far more than 400 horses. Same in-tank deal too.
All you need to use in-tank pump is:
1. A tank that supports an in-tank pump (it needs to hang in such a way that all fuel can be used up from the tank. They sell "hydramats" to help absorb and hold fuel in applications where the owner is retrofitting an electric pump into a tank not originally designed for one) The tank needs a feed and return line minimum.
The feed would goto a regulator. Vettes have a "filter regulator" mounted on the chassis which does both but I avoid them because they are not adjustable. Instead, mount a typical Aeromotive somewhere near the engine and plumb feed/return to it. Then from that regulator you can feed a fuel rail or carb or w/e
#10
Drifting
Lagonia- I had a problem with heat sink after the car was shut off. The heat from my NOM 454 boiled the fuel out of the carb on my 68 convert and required cranking the starter for at least 30 seconds to re-fill the fuel bowls before it would start. I mounted a Holley electric pump on the front side of the radiator mount on the lowest point on the car and tied into the existing fuel line from the gas tank. Used a pressure regulator installed between the pump and carb with a return line to the gas tank. Power goes thru a relay- check online to see how to wire for your car so it has power only with the motor running and the ignition switch on. It solved my dry start problem. I turn on the ignition, count to ten while the pump re-fills the carb and it fires up instantly when I turn the key to start. .
#11
Melting Slicks
I don't see the need in your case, but if I did change a 79 to an electric pump I'd likely use a 82 EFI pickup in the tank and put a TBI pump into it. Pick a brand like Walbro. Then, put a regulator under the hood to control the pressure to the carburetor.
If you are concerned about having it simply powered with the ignition on via a relay, there are ways to wire it so that it will only run when either the key is in the start position or there is oil pressure.
If you are concerned about having it simply powered with the ignition on via a relay, there are ways to wire it so that it will only run when either the key is in the start position or there is oil pressure.
If you're going with an adjustable regulator, go with the Holley; you won't find a better one cheaper.
You should know that there are a lot of Chinese knock-offs claiming to be Walbros that are not; and they fail quickly. Buy a real one from a reseller; not Ebay.
If you're afraid of fuel starvation, you can go with a Holley Fuel Mat in the tank, too but they're spendy...
Adam
Last edited by NewbVetteGuy; 01-21-2018 at 11:52 PM.
#12
Race Director
Prior to EFI, I was running a stock replacement carter fuel pump powering my 450hp 400ci small block, no problems.
After EFI, Walbro 255lph in the fuel tank via an Aeromotive Phantom sump setup. Again, no problems.
After EFI, Walbro 255lph in the fuel tank via an Aeromotive Phantom sump setup. Again, no problems.
#13
Racer
Just read your other post, A good aftermarket mechanical (high flow) fuel pump will work fine as well as an electrical set up. I think that decision will be based on cost and your skill level.
The WOT issue sure sounds like the carb needs to be dialed in.
What do the plugs look like? Maybe a WOT pass, shut car off, let it cool off and read the plugs. See if you are leaning out.
The stumble can also be caused by the accelerator pump, too big or too small. Any black smoke come out during this acceleration?
just 2 cents being thrown out there
The WOT issue sure sounds like the carb needs to be dialed in.
What do the plugs look like? Maybe a WOT pass, shut car off, let it cool off and read the plugs. See if you are leaning out.
The stumble can also be caused by the accelerator pump, too big or too small. Any black smoke come out during this acceleration?
just 2 cents being thrown out there
#15
Le Mans Master
Aeromotive Street Pump and regulator here. Very quiet and reliable. Mounted it inside tire tub in front of fuel tank. 3/8 feed with 5/16 return line. Wired to Hobbs switch. No oil pressure and the pump receives no power.
#16
I like electric pumps because they can't leak gas inside the engine when the diafragm breaks. ( don't know if this is the case on a C3, but is the case on other car's I've worked on).
Always use an inertia switch for your own safety. Can't hear the pump ticking over the exhaust
Always use an inertia switch for your own safety. Can't hear the pump ticking over the exhaust
#17
Racer
Thread Starter
The high flow mechanical pumps do not have a return line like the stock one does - is that an issue or does something different need to be plumbed out in case I go for one as a stop gap measure?
#19
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You want the return on the mechanical pump. People who have eliminated it have had fuel boiling issues. You can run a return from a regulator at the carb or if the pump regulates to the correct pressure then you can run a small orifice from the fittings by the carb to the return line. This lets some fuel flow back to the tank.