[lucky1]

Can operating an electric fuel pump near the tank simultaneously with the

Mechanical pump damage the mechanical pump ?


Thank you.

[steve25]

Why are you running both?
It’s very hard for a mechanical pump to suck thru a electric one, especially if the electric one is not gravity fed real well!

[67drake]

Tell me about it. When I bought my LeMans the previous owner had a cheap Mr. Gasket pusher pump installed back by the tank, above fuel level in the tank, that was in addition to the mechanical pump. That thing acted as a restriction if anything. Pulled the POS out and haven’t had an issue since.
Mount it lower than tank level or buy a pump that will lift fuel.

[Jay S]

I run check valves so the mechanical pump is able to pull full flow and bypass the electric. I turn on the electric as a helper pump for full power at the strip (just under 600HP on a couple cars) or to prime the carb. It is off most of the time. Carter sells an electric pump kit with the check valves, it was designed to run in tandem with the mechanical pump.

[tom s]

I have been running a pusher at the tank through #8 hose to a factory mech pump for 25 years.Electric is on a switch under the dash,run it when racing and for priming.NO issue pulling from the pusher with a pair of 750 NASCAR AFBs.FWIW,Tom

[JLMounce]

Is there a reason you don't move strictly to an electric pump in general?

The best setup in my opinion is to use an in-tank pump, in a new EFI ready tank that has an internal sump. Then use a bypass regulator to run the 5-7psi to your carb that it requires. You can even plumb that so it takes advantage of the stock line from the mechanical pump to the carb. Unless you're specifically looking for the mechanical pump to be in place, nobody would be the wiser.

It's a bit more funds, but it's not that much more work than plumbing the electric pusher. It's the best reliability play though.

[mgarblik]

Originally Posted by tom s

I have been running a pusher at the tank through #8 hose to a factory mech pump for 25 years.Electric is on a switch under the dash,run it when racing and for priming.NO issue pulling from the pusher with a pair of 750 NASCAR AFBs.FWIW,Tom

I have had that same set up for decades as well. Small pump on the frame rail looks like a fuel filter with a couple wires coming out of it. Something like 4 PSI.

[tom s]

Mine is a Holley,dont remember what one.Tom

[Formulajones]

Pretty much as JLmounce said, electric in the tank is the way to go if you've got a thirsty engine making some power.
It's clean, simple, and reliable and has the ability to support bigger power in the future if setup properly. It's also very quiet
Only real draw back is cost.

[Tom Vaught]

I have run an Electric Fuel Pump, at the tank for many years.
First a Holley "Red Pump". Then a Holley "Blue Pump". (Both had vane sticking issues).

Went with a Carter 4603 electric fuel pump and a By-Pass Circuit some years later.
Very dependable. E-pump was off unless priming carbs or "acceleration runs on the street". Fuel went thru the by-pass to the mechanical fuel pump.

Then I stepped up when Tanks,inc first came out with the in-tank pumps.

255 liter/hr normal installation with a good FP regulator.

Later went to a 400 liter/hr pump in the tank.

System in the car now is TWO EFI 450 liter pumps on a special fuel pump "dual mount cover" The latest EFI pumps are alcohol tolerant. Only one pump is used at a time, the other pump is a Back-up pump when I go on trips to the bridge.

The dual fuel pump mount (made in the Chicago area) required fuel tank mods to put
both 450 pumps in the tank. The tank is a aftermarket (Tanks,inc tank).

Very sweet system and the fuel with be there if I reinstall a vortech supercharger on the car: YSI (1200 HP Unit).

Tom V.

Spend the money on a good fuel system.

[slowbird]

We did it for years and years never an issue

[sdbob]

Ran a Conelec pump on 421 GP back in the 70s with mechanical pump. Then took same pump put on my SD. Lasted till about 8 yrs ago, pump finally gave out. Only used electric at the strip or on street for maximum fuel delivery. As car would shut off in 2nd when hot without. Now bought a Robb Mc high volume mechanical pump, 500hp. Havent got it mounted as it is little physically different,close though.

[Jay S]

I just help someone that had a pump similar to that Mr Gasket electric pump in series with the stock pump, a few weeks ago on a OHC tempest. It wasn’t working very well and was flooding out occasionally. It has the pump similar to the Mr Gasket, I call them chatter pumps. I think they are diaphragm operated. They are usually rated for 4 psi, but when they go out of stroke I think they have a tendency to spike the pressure and push fuel past the needle and seat. Plus the flow is too irregular to work very well consistently . Maybe someone else’s has made one work, but I have never had success running them with carb with the mechanical pump, or by themselves either for that matter. I thought maybe it would halfway work in series with a mechanical pump, but that wasn’t the case. The pusher pump needs to be a vain style pump like the Holley red street pump or Carter Street pumps, or similar pumps to work very well. Something that has a built in regulator with consistent pressure, and doesn’t just go out of stroke when there is no demand.


I have two cars with in tank pump Tanks Inc systems feeding carbs. They work pretty much flawlessly, but are quite a bit more elaborate to set up versus the pusher and mech pump with the check valves. On my cars with Tanks set ups the fuel system was done from scratch. I just tied into the stock line adding the pusher pump with the stock mechanical pump on the pusher pumps.

Versus feeding a fuel injection set up, the in-tank set up returns a lot more fuel when set for the low pressure. The return line really needs to be as big as the feed line. My cars with the in Tanks setup are hard to keep clean where the tank vents from the fuel vapors. I suppose you could use a charcoal canister and fix that. Lots of vapors coming out of it on a hot day though, might take a couple canisters and a pretty elaborate set up to the carb for making it happy. The vent is stupid simple.

I have another car with a sump welded to the stock tank and is all electric with tandem electrics. One pump pulls from the stock factory pickup, and the other pulls from the sump with a check valve inline, running low pressure street pumps with no regulator, ussually kick in the sump pump at the track. I have another car with a fuel cell and 2 holley's blue 15psi pumps and a fuel regulator. 2 trash grinders is a bit on the loud side!

[Formulajones]

Originally Posted by Jay S

I have two cars with in tank pump Tanks Inc systems feeding carbs. They work pretty much flawlessly, but are quite a bit more elaborate to set up versus the pusher and mech pump with the check valves. On my cars with Tanks set ups the fuel system was done from scratch. I just tied into the stock line adding the pusher pump with the stock mechanical pump on the pusher pumps.

Versus a feeding a fuel injection set up, the in-tank set up returns a lot more fuel when set for the low pressure. The return line really needs to be as big as the feed line. My cars with the in Tanks setup are hard to keep clean where the tank vents from the fuel vapors. I suppose you could use a charcoal canister and fix that. Lots of vapors coming out of it on a hot day though, might take a couple canisters and a pretty elaborate set up to the carb for making it happy. The vent is stupid simple.

That's how I set them up here. Yeah it's a bit involved to set up and when said and done costs about a grand start to finish but it's a fantastic setup for a bigger HP carb setup, and about a necessity if going EFI.
In fact I ran these Tanks Inc fuel setups on carbs for years and when those cars were switched to EFI, it was just as simple as changing the spring in the regulator for EFI pressures and done.
When I do this I always set them up with 1/2" feed and return lines so when I'm running carb pressures, the 1/2" return does the job.

If the car is equipped with the charcoal cannister, I use it. This requires welding some extra connections on the Tank Inc tank so I can hook up all the lines required, but will function as the factory intended when finished, and vent through the cannister. Works excellent.

In fact the Tanks Inc systems have worked so well for me I completely modified the floor of a Vega I'm restoring now just to accept a 2nd Gen F-body Tanks Inc 21 gallon tank, complete with a walbro pump and sender etc.... It's also getting 1/2" feed and return lines, and will be supplying fuel to a carbed 500hp 327. That way the fuel system is solid and ready for more power later.

[455dan]

Originally Posted by lucky1

Can operating an electric fuel pump near the tank simultaneously with the

Mechanical pump damage the mechanical pump ?


Thank you.

Been running the SD TA that H-O Racing built for street the way they set it up for a Q-jet for 44 years.

They used Carter pumps on it. Rotary mounted in front of the tank to a larger than stock line to a mechanical Carter on the engine. The original Rotary electric finally failed about 8 years back so just replaced it with another identical unit from Carter. Still has the mechanical pump that was on it in 1979...
My understanding was that with the small fuel bowl of the Q jets having more volume (not pressure and IIRC it is the lower 4ish psi unit) is key and helps at the top end keeping the bowl full.

I don't believe it wears out anything having both a mechanical and electric rotary.

[Jay S]

Originally Posted by Formulajones

That's how I set them up here. Yeah it's a bit involved to set up and when said and done costs about a grand start to finish but it's a fantastic setup for a bigger HP carb setup, and about a necessity if going EFI.
In fact I ran these Tanks Inc fuel setups on carbs for years and when those cars were switched to EFI, it was just as simple as changing the spring in the regulator for EFI pressures and done.
When I do this I always set them up with 1/2" feed and return lines so when I'm running carb pressures, the 1/2" return does the job.

If the car is equipped with the charcoal cannister, I use it. This requires welding some extra connections on the Tank Inc tank so I can hook up all the lines required, but will function as the factory intended when finished, and vent through the cannister. Works excellent.

In fact the Tanks Inc systems have worked so well for me I completely modified the floor of a Vega I'm restoring now just to accept a 2nd Gen F-body Tanks Inc 21 gallon tank, complete with a walbro pump and sender etc.... It's also getting 1/2" feed and return lines, and will be supplying fuel to a carbed 500hp 327. That way the fuel system is solid and ready for more power later.

Just under a grand is pretty close to what I spent not counting labor, 1/2” the entire way.

Good good to know that the existing charcoal setup can work with the tanks system. So far I have put them on 69 and older cars without a factory charcoal canister. I would want to try running if the system was on the car already.

[glhs#116]

Originally Posted by Jay S

I run check valves so the mechanical pump is able to pull full flow and bypass the electric. I turn on the electric as a helper pump for full power at the strip (just under 600HP on a couple cars) or to prime the carb. It is off most of the time. Carter sells an electric pump kit with the check valves, it was designed to run in tandem with the mechanical pump.

I've been really closely pondering something like this. But I've had some thoughts that are maybe specific to just how I think about things...

• I am sorta into really minimising the modifications (especially obvious ones). For example, I sorta really want to keep the stock pump-to-carb hard line and mechanical pump
• I'm pretty keen that an electric pump not stay running in case of an accident or something. Usually this means an oil pressure switch in conjunction with something that can override that while starting
• I hate electrical complexity
• I hate the sound of an external electric pump
• I don't want to have to replace the tank and replumb everything

So what I've been leaning towards as an idea is this:
• Keep my factory style mechanical pump
• Add a pusher pump with bypass like https://www.summitracing.com/parts/crt-p4602rv
• Add a full throttle switch like one of these "nitrous switches" and tie that to the electric pump

To my thinking this could be about perfect. Nice quiet stock functionality for most street driving. Electric kicks in for passing and at the track without me having to remember anything. I can just briefly hold the pedal down for a few seconds before starting if I want to prime. No worries about the pump running when the motor's off because of the throttle return spring and no need to plumb some oil pressure switch.

To my thinking this seems almost a flawless plan. Am I missing something obvious? Has anyone used a good WOT switch that fits nicely to a QuadraJet?

Sam

[OG68]

Originally Posted by glhs#116

To my thinking this seems almost a flawless plan. Am I missing something obvious? Has anyone used a good WOT switch that fits nicely to a QuadraJet?
Sam

Have you considered using an automatic 'Downshift' switch?

[lucky1]

Thanks for the response. 👍

[steve25]

I would want a roll over safety switch even in a street car that has a electric pump that I have added!