Dr L-88

Hi Jim,

What problems, if any, might one encounter with using a small inline electric fuel pump with a max 5 psi (near the tank outlet) for filling a carburetor (or fuel injection) for ease of starting. Turn the pump on to fill the carb, then turn it off and let the accelerator pump and mechanical fuel pump handle fuel delivery from there. I’m asking because my car may sit for a few weeks between starts which results in long cranking just to get fuel to the carb.

Yeah, I know, IFFFFFFF I would drive it more often I wouldn’t have this problem. Hope you’re doing well Jim. I sent you an email a week or so ago just to catch up.

As always, thanks in advance.

Rex

Vette5311

Just my 2 cents worth, I have this same problem, I have a Holley carb. I keep a squirt bottle with gas and put fuel in the float bowls through the vent tube. Starts right up.

Chalie M

Hey Rex I hope you & Jim are well ( from what I remember reading here on the Forum it’s been a tough couple of years for you both, my heart goes out for you guys…)..

To give input to your question I would think as long as the electric pump is a full by-pass type pump (I don’t know if that’s the correct term/description or not? The electric pump would allow fuel to go fully through the pump & siphon 100% when it was off I wouldn’t see a problem using it on a carb or Rochester F.I. ?

ALWAYS interesting to hear Jim’s input?

I know you got some serious cars in your stable & probably know this already:-).?

** I always did not mind when I would start my 65 (327/365) & it didn’t start right up after sitting, Actually I would always crank my car up first for a couple of seconds to get some oil going through the engine & prime the fuel bowl some especially up North here in Pa. In those winter months.
After pushing down on the gas pedal a couple of times to set the choke & get the accelerator pump to squirt some gas in the carb it would light right up on the next crank, but maybe down where you are at it doesn’t get that cold:-)?
Since upgrading to the Rochester F.I. (my first winter with it ) I’m thinking on maybe doing the same starting procedure, I know it doesn’t have a accelerator pump like the carb did as long as the choke was set on the F.I. It would fire immediately I’ll see this winter?**

Regards Chalie
Ps (not sure if you got to use them Velocity stacks yet would like to see a pic of what you’re working on with them?)

DansYellow66

I did this for years. It didn’t seem to work for me as well or reliably as using a squirt bottle. I used a Holley pump and even with attempts to insulate it from the frame, I was probably reluctant to run it long enough to fully fill the bowls due to the noise. But it never seemed to hurt the performance of my mechanical pump when it was shut off, although my car has never been to the drag strip to give a really full-out test of the system. I finally bypassed it a couple years ago but it’s still mounted under there along with the wiring and switch.

Leo Guggenbiller

Rex, IWhen I bought my 61 back in 76 it came with a Carter electric fuel pump bolted to the rh frame rail just in front of the rear spring hanger. It remains there today. It is nice to be able to fill the fuel bowl before cranking the engine. I installed a Holley fuel regulator to keep pressure at 4 psi to the carb. It’s worked flawlessly until late, it has started weeping fuel from the electrical terminals. I am considering replacing it with a stock engine driven mechanical pump. I believe I will be following this post closely for what Jim has to say. BTW my 61 is a fuel car. Looking forward to Mr. Lockwood input.

Happy New Year to all
Drive em safe
Leo

jim lockwood

Hi Rex,

I think the concept of the priming pump makes perfect sense.

Whether or not you can make it work probably comes down to how the electric pump is constructed. If the electric pump doesn't have some sort of internal one-way valving, I think the mechanical pump would have trouble pulling fuel through it. The only electric pump I've ever disassembled was one of the low cost Carter pumps. That pump did NOT have any internal valving and I believe it would have blocked flow when powered off. Other pumps may have different internal construction. I just don't know.

If you can stand the noise of the electric pump, I think you'd be well served by using it in lieu of the engine-mounted mechanical pump. You'd gain the advantages of instant priming and cooler fuel (reducing the probability of fuel percolation).

Or, as you point out, you could just drive your car more often!

Jim

R66

Jim must be sleeping.
It would seem an electric pump for priming might be helpful as long as it wasn't used in series with the mechanical pump when cranking or the engine is running. This would probably over pressurize the needles and seats and flood the car without a regulator on the carburetor inlet.
The only other question I would have is if the pressurized fuel entering the inlet side of the mechanical pump could push the inlet check valve out of it's seat and make the mechanical pump unserviceable.
I am assuming both pumps are in the same fuel line in series.

OPS, Jim woke up.

jforb

I've used both electric and mechanical pumps on several cars, just because modern fuel evaporates so readily. As long as it's a low pressure low flow electric pump, of the "pulse" type, it works fine to run the electric pump just occasionally. The vane type pumps will probably block fuel flow when not running, so probably won't work in series. But you could TEE in a vane type pump.

I've never tried this on a performance car, that requires significant fuel flow.

Don't worry about the mechanical pump being damaged by having fuel forced through it, as long as the pump doing the forcing is of the low pressure type. It won't dislodge the check valves, or anything like that.

C2Dude

On low wing aircraft it is common to have an electric fuel pump inline with the mechanical. Used when starting, takeoff and landing, off in cruise. I used a Facet pump in the RV-6 I built. When switched off, fuel flows through it without restriction. Not very noisy either. If you consider a aviation type pump keep in mind they have AN fittings at both ends and that the angle of the bevel on those fittings is different than those on automotive fittings

plaidside

But I normally only do this after winter storage. If my cars sit for a week or two, I then tap the throttle to set the choke and the crank the engine for a seconds and stop. Then I depress the throttle, but not on my fuelie, and crank again. Repeat if necessary.

Dr L-88

Thanks to all for your comments. I had actually done this many years ago (yep, in the last century) on my 59 Corvette SS/GT (IHRA drag car). Of course it had an aftermarket high volume mechanical pump and a small AC electric pump in conjunction with a Holley pressure regulator set at 6 psi. Worked fine, had a lot of fun and spent a LOT of money. Did I mention I had a lot of fun ?

Perhaps I should have clarified in my original post that my main concern is just what “jforb” described. I’ve heard of this electric and mechanical pump combination resulting in damage to the STOCK mechanical pump and fuel finding its way into the oil pan and then, well, suffice it to say things got really ugly really quickly from there.


jforb - “Don't worry about the mechanical pump being damaged by having fuel forced through it, as long as the tank pump doing the forcing is of the low pressure type. It won't dislodge the check valves, or anything like that.”

Again, thanks for all who contributed.

Good to hear from you Jim. Southern Illinois isn’t that far from me.

jim lockwood

If you feel like venturing out, I'll have an extra pair of eclipse glasses with me. We'll be in Hamilton County.

Leo Guggenbiller

Carter electric fuel pump
This is the set up on my car at this moment. It will not inhibit flow when not running as I have cut the fuel line downstream and the tank is draining as I post this.

Drive em safe
Leo

Dr L-88

I have a similar fuel system on my 57 Jr. Stocker. Carter pump, Fram filter, Holley regulator, no mechanical pump.

TCracingCA

On one of my cars early on, I thought the thing to do was keep the mechanical stock fuel pump, but ended up for daily street driving added an electric pump that I could switch on. I split the line out of the tank, and connected using the return line going forward and plumbed to a fuel log. I had the mechanical feeding one end of the fuel log and the other end plumbed to the fuel log. Other than the fuel log, it looked stock. Thus starter key on, prime the carb, switch off, and then crank starter, cycling the mechanical fuel pump, instant start. It worked, so never tried anything else. In the modern I just run all electric fuel pumps, have two in all cars, in case one fails.

GordonR

I have installed low pressure Facet pumps frame mounted on a rubber insulator. I used a momentary switch wired to B+ with the instruction of running the pump for around 5 seconds to fill the bowls. I too have no experience with a high performance application outcomes.

Drummer Boy

Jim,
Would not an electric pump mounted inside the fuel tank be an option here as well? Inside the tank there would be far less noise. Yes, you would have to either 1. Cut larger hole in the existing tank or 2. Replace the tank with one that is meant for a submersible fuel pump.

Eddie

jim lockwood

Good question. I don't have any experience with in-tank pumps, Eddie. Perhaps someone with an EFI system could chime in.

jforb

GM used in tank pumps with carbs in a few cars in the 70s...Vega/Monza and Riviera come to mind.

Setting up a return line as well, and a bypass regulator or filter, might also help with vapor lock issues when it's warm out.

All kinds of fun things you can do with cars.

Dr L-88

Whoa Nellie…………. again I wasn’t looking to redesign the wheel here, but I do appreciate all the ideas……………. perhaps others can glean some information that will be useful to their fuel delivery situation. However…….. for ME, and my cars, 64 Z-06 with dual air meter FI and 67 L-88 tribute, I’m DEFINITELY NOT gonna modify the tank on either car. I was merely looking for a quick and easy method to fill the fuel bowl to make starting quicker after sitting for a while (too long) and fuel having evaporated. Maybe the squirt bottle is my best option, in conjunction with a more frequent driving schedule.

Thanks to all who contributed. I’ll take a standing 8 count at this point. Y’all can continue this discussion while I look for just the right squirt bottle.

Everyone take care and stay warm and dry 🥶